travel jabs side effects

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• Typhoid Vaccine (Intramuscular Route)

Side Effects

Drug information provided by: Merative, Micromedex ®

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

• general feeling of discomfort or illness
• pain, redness, swelling, tenderness or a lump at the place of injection
• unusual tiredness or weakness

Incidence not known

• Difficulty in breathing or swallowing
• hives, itching, or redness of the skin
• swelling of the eyes, face, or inside of the nose

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

• difficulty in moving
• joint pain or swelling
• muscle aches, cramps, pain, or stiffness

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

• Precautions

Portions of this document last updated: Feb. 01, 2024

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Travel vaccinations

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• Vaccination is a way to protect yourself against certain infections.
• Travelling can expose you to serious diseases that rarely occur in Australia.
• You can protect yourself by becoming vaccinated against diseases that are more common overseas.
• Vaccines are usually very safe with only minor side effects.
• Visit your doctor 6 to 12 weeks before you travel, so you can have any vaccines you might need.

What is vaccination?

Vaccination helps keeps you safe from certain infections. Vaccines contain tiny amounts of dead or weakened viruses, bacteria, or other substances that help your immune system prepare to fight a future infection. Vaccination is safe, effective and especially important when travelling.

Why should I get vaccinated before I travel?

Many infectious diseases are uncommon in Australia, due to widespread vaccination and other public health measures. This is not the case in many other countries.

Travelling can make it more likely for you to catch infectious diseases that are very rare in Australia.

These infections can cause serious illness, even in people who are usually fit and healthy. Sometimes they can be life-threatening. If you return to Australia with an infectious disease, you may also put other people at risk.

People who are pregnant , babies and young children , older people and people with a weakened immune system have a higher risk of infection when travelling. For these people, getting vaccinated before travelling is even more important.

Some countries require you to be vaccinated against certain diseases before you can visit. If you do not have the required vaccinations, they may refuse your entry, or require you to have the vaccination(s) at the border. Talk to your doctor about which vaccines or boosters you may need before you travel.

Which vaccines do I need before travel?

Health risks vary from one region to another. Over time new outbreaks may occur and new vaccines may become available.

If it has been a while since your last vaccinations, you may need boosters. That is why it is important that you visit your doctor well before your trip to discuss vaccination.

Your doctor will consider factors such as:

• your vaccination history
• whether you are pregnant or planning a pregnancy
• any past or present illnesses, and your general health
• the season of travel
• your destination(s), length of stay and type of travel

It is important to keep up to date with your vaccinations for diseases including:

• measles , mumps , rubella
• influenza (flu)
• chickenpox (varicella)
• polio (poliomyelitis)
• diphtheria , tetanus and whooping cough (pertussis)

You may also need one or more vaccines for diseases such as:

• hepatitis A and/or hepatitis B
• yellow fever
• tuberculosis (TB)
• meningococcal disease
• Japanese encephalitis

There may be other infections, unique to countries or regions, that are not covered in this list. Your doctor can advise you of any other vaccinations you may need before you travel.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, vaccine clinics and other health services.

How long before I travel should I see my doctor?

You should see your doctor at least 6 weeks (and preferably 12 weeks) before you leave Australia. This will give your immune system time to respond to any vaccines you need. Also, you may need more than one dose of some vaccines.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

What if I have been vaccinated against these diseases in the past?

You should still check with your doctor if you need any vaccinations for travel. Even if you have been vaccinated before, your immunity to some diseases reduces with time and you may need a booster.

Are vaccines safe?

Vaccines used in Australia are approved for use by the Therapeutic Goods Administration after a careful safety testing process. Overall, the chance that a vaccine will cause serious harm is extremely small. Being vaccinated is far less risky than the risk of getting a disease because you were not vaccinated.

If you have a weakened immune system due to certain diseases or medicines, ask your doctor how this affects your vaccination schedule. Your doctor will review your general health and ask you about any medicines you take to make sure vaccination is safe for you.

Rarely, a person may develop an allergic reaction to a vaccine. Always let your doctor know if you have any allergies or if you have reacted to a vaccine in the past. This will help them advise whether a particular vaccine is suitable for you.

What are the side effects of vaccinations?

All medicines, including vaccines, may have side effects. In the case of vaccines, side effects are very minor and usually go away within a few days. Common side effects are:

• redness, pain and tenderness at the site of an injection
• headache , nausea or tiredness

If you are concerned that you have side effects related to a vaccine, see your doctor. You can also report and discuss possible side effects by calling the Adverse Medicines Events (AME) Line on 1300 633 424 (1300 MEDICINE).

How much do vaccinations in Australia cost?

The cost of vaccinations in Australia depends on the vaccination. Many vaccines are free under the National Immunisation Program (NIP) which you have access to if you have Medicare .

Some travel vaccines may not be covered by the NIP, and you will need to buy them. You can check costs with your doctor. Ask your doctor if there is a fee for the consultation and vaccination service, as this can vary in different clinics.

What is the Australian Immunisation Register (AIR)?

The Australian Immunisation Register (AIR) is a national register that records all vaccinations given to people in Australia. It helps you to track your immunisations. You can easily check your immunisation history by applying for a statement through your myGov account online or asking your doctor. If you have Medicare, you will automatically be added to the AIR when you receive any vaccines.

Resources and support

For more information on travel health visit the Immunisation for travel page at the Department of Health .

For information about vaccine side effects and safety, visit:

• NPS MedicineWise
• Department of Health

To report or discuss possible side effects from vaccination, call Adverse Medicines Events (AME) on 1300 633 424 (1300 MEDICINE) from anywhere in Australia 9am–5pm AEST (except on NSW public holidays).

Learn more here about the development and quality assurance of healthdirect content .

Last reviewed: November 2023

Recommended links

• Recommendations for severe allergic reactions (opens in a new window) choosingwisely.org.au
• 5 questions to ask your doctor (opens in a new window) choosingwisely.org.au

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• Safe travels! 10 tips for a healthy holiday
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Vaccine Side Effects

Most people don’t have any serious side effects from vaccines. The most common side effects—like soreness where the shot was given—are usually mild and go away quickly on their own.

What are common side effects of vaccines?

The most common side effects after vaccination are mild. They include:

• Pain, swelling, or redness where the shot was given
• Feeling tired
• Muscle and joint aches

Fainting can also happen after any medical procedure, including vaccinations.

Keep in mind that most common side effects are a sign that your body is starting to build immunity (protection) against a disease. Learn more about how vaccines provide immunity .

What about serious side effects?

Serious side effects from vaccines are extremely rare. For example, if 1 million doses of a vaccine are given, 1 to 2 people may have a severe allergic reaction.

Signs of a severe allergic reaction can include:

• Difficulty breathing
• Swelling of your face and throat
• A fast heartbeat
• A bad rash all over your body
• Dizziness and weakness

If you experience a severe allergic reaction, call 9-1-1, or go to the nearest hospital. Call your vaccination provider or your healthcare provider if you have any side effects that bother you or do not go away. Please report any potential side effects experienced from vaccination to the Vaccine Adverse Event Reporting System , a program co-managed by the U.S. Centers for Disease Control and Prevention and the Food and Drug Administration to ensure that all recommended vaccines remain safe.

Keep in mind that getting vaccinated is much safer than getting the diseases vaccines prevent. Learn more about vaccine safety .

What if I feel sick after getting vaccinated?

If you experience a severe allergic reaction, call 9-1-1, or go to the nearest hospital. Talk with your doctor if you’re concerned about your health after getting vaccinated. You or your doctor can choose to report the side effect to the Vaccine Adverse Event Reporting System (VAERS) .

In the very rare event that a vaccine causes a serious problem, the National Vaccine Injury Compensation Program (VICP) may offer financial help to individuals who file a petition. Learn more about VICP . The Countermeasure Injury Compensation Program (CICP) may help pay for the costs of medical care and other expenses for people seriously injured from a COVID-19 vaccine. Learn more about the CICP .

Talk with your doctor if you’re concerned about your health after getting vaccinated. You or your doctor can choose to report the side effect to the Vaccine Adverse Event Reporting System (VAERS) .

In the very rare event that a vaccine causes a serious problem, the National Vaccine Injury Compensation Program (VICP) may offer financial help to individuals who file a petition. Learn more about VICP .

Do childhood vaccines cause autism? No. Vaccines do not cause autism. Many studies have looked for a link between vaccines and autism, and the research clearly shows that vaccines don’t cause autism. Learn more about these studies and autism .

Find information about specific vaccines and possible side effects .

Get Immunized

Getting immunized is easy. Vaccines and preventive antibodies are available at the doctor’s office or pharmacies — and are usually covered by insurance.

Find out how to get protected .

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A Timeline of COVID-19 Vaccine Side Effects

Key takeaways.

• Most people have a sore arm right after being vaccinated, and more body-wide effects like fever and chills within 8 to 12 hours. 
• Most side effects stop within 48 hours.
• The vaccine cannot cause a COVID-19 infection, so symptoms mean your body is building a healthy immune response.

If you’re getting ready for the first, second, or booster dose of your COVID-19 vaccine, you may wonder about what side effects to expect and how to deal with them.

Some side effects happen right after your shot, like mild pain in your arm. Others may take hours to develop. Remember that with the two-dose vaccines like Pfizer-BioNTech and Moderna, you may notice more side effects after the second shot.

Illustration by Theresa Chiechi for Verywell Health

This article offers a step-by-step timeline of possible symptoms to help you understand what to expect after the jab.

Right After Vaccination

The COVID vaccines are intramuscular , or "IM" for short. That means the liquid in the syringe goes directly into a muscle when the needle goes in.

Your body's immune system sees this as a threat, and pain at the injection site is part of its response. That's why your arm may feel sore, turn red, or swell a bit. Some people who get the Moderna vaccine may experience "COVID arm," a delayed skin reaction with raised, red welts on the arm.

The mild pain that COVID-19 vaccines may cause is similar to what some people report after the tetanus vaccination, Michelle Barron, MD , senior medical director of infection prevention and control for the University of Colorado Health, tells Verywell.

The Centers for Disease Control and Prevention (CDC) recommends placing a cool, wet washcloth over the area to help ease any pain. Moving or exercising your arm also may help.

15 Minutes After Vaccination

The risk of anaphylaxis —a severe allergic reaction to the vaccine—is lower just 15 to 30 minutes after vaccination. This reaction is very rare, but the CDC requires everyone who gets the vaccine to wait in the clinic for 15 minutes after getting the shot, just in case it happens.

“If you've had allergic reactions in the past, we want people staying for 30 minutes,” Kate Mullane, DO, PharmD, professor of medicine and infectious disease specialist at the University of Chicago, tells Verywell.

Although it's rare, it's possible to have an allergic reaction within the first 15 to 30 minutes after the jab. It's much more common to feel some soreness in your arm at the injection site, and the surrounding skin may get a little red and swollen.

12 Hours After Vaccination

Other side effects may start within a few hours, or up to 12 hours after the shot. People commonly report systemic side effects, like fever, headaches, muscle aches, joint pain, chills, and fatigue.

In the Pfizer-BioNTech vaccine trials, more than 77% of participants reported at least one systemic reaction. The most common were fatigue, headache, and new or worsened muscle pain.

Some less common side effects include nausea and swollen lymph nodes (especially in the armpit).

There's no need to worry about any of the flu-like symptoms. The side effects mean your body is working hard to build the antibodies and cells it will need to fight the virus, if or when you are exposed to it.

“Although you feel terrible, it's a good thing, because those systemic effects are telling you that your body is making an immune reaction,” Mullane says.

12 to 48 Hours After Vaccination

Once these body-wide side effects set in, they can last for 12 hours or more. Experts say these side effects should all stop within 24 to 48 hours after your shot, though you may still have some slight fatigue or arm soreness after that.

Mullane says it’s best to avoid important events or take on key tasks the day after your vaccination if you’re concerned about the side effects. That's because your vaccine appointment and the window for peak symptoms aren't likely to happen at the same time. Most side effects come later.

It’s OK to take an anti-inflammatory medication like Tylenol or ibuprofen to relieve any symptoms. But Mullane says not to take it before the shot, as it can interfere with your immune response.  

Many people report a sore arm, mild fever, or other symptoms after vaccination. These are not serious and will go away on their own. An August 2021 report from U.S. health officials found that, with 187 million people in the U.S. getting at least one dose, the vaccine benefits are far greater than the risks. But rare and serious complications may occur. They include:

• Guillain-Barré syndrome  (Johnson & Johnson)
• Thrombosis , or blood clots (Johnson & Johnson)
• Myocarditis (Pfizer-BioNTech and Moderna)

After 48 Hours

If you still have severe symptoms two full days after your vaccination, you may want to talk with your doctor to see what to do next. It’s possible that while you had vaccine side effects, you were also ill with COVID-19 or a different infection.

“If the symptoms persist beyond the 48 hours and aren't getting better, or if you develop any kind of respiratory symptoms, you should get evaluated,” Barron says.

It’s important to note that you cannot get COVID-19 from any of the approved vaccines. However, it can take up to two weeks after the second shot of the two-dose vaccines, or the single dose of the Johnson & Johnson, to mount a full immune response.

A COVID infection and its symptoms are still possible until the end of this two-week waiting period. It also is possible to have a breakthrough infection, which means you have COVID even though you got the vaccine.

What This Means For You

If you’re worried about how your body may respond to the vaccine, plan to take it easy in the day or two after your appointment. While it’s safe to exercise, go to work and be around other people during that time, side effects like fever and fatigue may make it uncomfortable to do so.

Side Effects Vary

When you hear about other people's experiences, remember that the vaccine side effects can vary greatly. Barron says that, in general, the side effects reported in the clinical trial data are the same as what people say after getting their own vaccines. 

“In the clinical trials, younger people were more likely to have reactions than older people,” Barron says. “They tended to have more of the systemic symptoms like the fever and chills and older people just reported a little bit of fatigue and arm soreness.”

“The healthier you are, the more in tune your immune system is, the higher the likelihood that you're going to have side effects because your immune system gets turned on,” Mullane adds.

If you don’t have intense side effects, like a high fever or body aches, it doesn’t necessarily mean your body won’t be protected against the virus. The time or intensity with which people’s immune systems respond to vaccines can differ based on many factors.

While the side effects can cause some pain and discomfort, Barron says that these effects are far better than the risks of getting sick with COVID-19.

“Forty-eight hours of side effects versus potentially the risk for hospitalization and death—I sort of think that favors the vaccine,” Barron says. “If there's any hesitation because of side effects, I’ll say the disease is far worse…or has the potential to be far worse.”

The best way to prepare yourself for a COVID vaccine is to learn about the possible side effects to expect. For most people, this means some mild symptoms like a sore arm, or flu-like symptoms that last up to two days before going away.

In rare cases, a serious reaction or complication may follow COVID vaccination. That's not a reason to avoid a vaccine because the benefits still outweigh the risks, but it is a good idea to keep a close eye on how you feel after getting your shot. Call your healthcare provider if you think your symptoms are serious.

Frequently Asked Questions

Part of the body's immune response to a vaccination is swelling in the area where the injection occurred. As a result, this causes soreness at the injection site. Movement and stretching can help by loosening up the muscle and decreasing inflammation, while also allowing the medication to spread out from the area.

COVID-19 vaccine side effects are very common and most often occur after the second dose for those vaccines requiring a two-dose series. One study showed that 70% and 75% of participants reported soreness at the injection site after the first and second doses, respectively. Up to 70% reported body-wide reactions like fatigue, headache, fever, and muscle aches.

COVID arm may appear about seven days after receiving the Moderna vaccine. It usually goes away within a few days but may last up to 21 days.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page .

Johnston MS, Galan A, Watsky KL, et al. Delayed localized hypersensitivity reactions to the Moderna COVID-19 vaccine: A case series .  JAMA Dermatol . 2021 May;157(6):716. doi:10.1001/jamadermatol.2021.1214

Centers for Disease Control and Prevention. Possible side effects after getting a COVID-19 vaccine.

Centers for Disease Control and Prevention. Interim considerations: preparing for the potential management of anaphylaxis after COVID-19 vaccination.

Centers for Disease Control and Prevention. Local reactions, systemic reactions, adverse events, and serious adverse events: Pfizer-BioNTech COVID-19 vaccine.

Rosenblum HG, Hadler SC, Moulia D, et al. Use of COVID-19 vaccines after reports of adverse events among adult recipients of Janssen (Johnson & Johnson) and mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna): Update from the Advisory Committee on Immunization Practices — United States, July 2021 . MMWR Morb Mortal Wkly Rep. 2021;70:1094-1099. doi:10.15585/mmwr.mm7032e4

Sheltering Arms Physical Rehabilitation Center. 5 exercises to reduce arm soreness after the COVID-19 vaccination .

Memorial Sloan Kettering Cancer Center. The second dose of a COVID-19 vaccine: Side effects, why they happen, and how to treat them .

Chapin-Bardales J, Gee J, Myers T. Reactogenicity following receipt of MRNA-based COVID-19 vaccines .  JAMA . 2021;325(21):2201. doi:10.1001/jama.2021.5374

Johnston MS, Galan A, Watsky KL, Little AJ. Delayed localized hypersensitivity reactions to the Moderna COVID-19 vaccine: a case series .  JAMA Dermatol . 2021;157(6):716. doi:10.1001/jamadermatol.2021.1214

By Claire Bugos Bugos is a senior news reporter at Verywell Health. She holds a bachelor's degree in journalism from Northwestern University.

Vaccinations and Adverse Reactions FAQs

Reactions to vaccines.

Vaccines are both effective and safe, however side effects sometimes occur. These are usually mild reactions and are part of the normal immune response to vaccination. Serious reactions to vaccination such as anaphylaxis are extremely rare.

Common mild vaccine reactions

Mild reactions can affect up to 15% of people following vaccination. These reactions generally occur within a day or two of immunisation and are transient. Live viral vaccines (MMR, Yellow Fever, Varicella) can occasionally cause symptoms such as fever, headache, tiredness and/or rash. These may be delayed until several days after vaccination.

Uncommon, severe adverse reactions

Although they can be severe, most rare vaccine reactions occur soon after immunisation, are self-limiting and do not lead to long-term problems. Anaphylaxis, for example, although potentially life-threatening, is quickly and very effectively treated and has no long-term effects. After vaccination, it is very important to stay for 10-15 minutes of observation.

If you have any concerns about the safety or effectiveness of vaccines, please feel free to discuss this with one of our doctors.

What are the likely side effects?

Modern vaccines are less likely to cause side effects, and there are no restrictions on normal activities - most people can work, drive a car, play sport or go to the gym. Still, it is better to take it easy if you are experiencing any side effects. Modern vaccines do not leave a scar.

If you have a history of fainting after injections, make sure you tell the doctor. You may be asked to lie down during vaccination and for a while afterwards so we can be sure you are feeling well before leaving the clinic.

What if I have a cold?

It is medically-safe to be vaccinated if you have a runny nose, sore throat or cough. You should delay vaccination if you have a fever over 39°C or are sick enough to have to stay in bed.

Allergic reactions (Anaphylaxis)

Allergic reactions are rare but may be very serious. After vaccination, notify one of our staff immediately if you feel:

• Warm or itchy, or develop a rash
• Faint (especially on standing up) or dizzy
• Shortness of breath, or start to wheeze or cough
• Your throat, face, hands or limbs begin to swell
• Nausea or stomach pain
• Suddenly tired

Symptoms usually develop within 15 minutes of vaccination, (hence the need to wait in the clinic after vaccination). Occasionally allergic symptoms can occur several days later. If you develop one or more of the above symptoms after leaving the clinic, seek medical help immediately. Persons with severe allergies to eggs may not be able to be immunised against yellow fever, flu, and MMR. Travellers with penicillin allergy however can be vaccinated safely.

Fevers and feeling unwell

Live virus vaccines such as Yellow fever, varicella (chickenpox) and MMR (measles, mumps, and rubella) may cause a fever, headache, tiredness and muscle aches in up to 15% of people, beginning 3-10 days after vaccination. MMR may also cause a transient rash in 5% of people. Most vaccines used today contain killed organisms or fragments of organisms and cannot cause the illness they are used to prevent. A good example is the flu vaccine which cannot cause the flu. However, some people react more strongly to vaccines and may feel unwell afterwards. If you develop a fever or become unwell after vaccination, please call our clinic and speak to one of our doctors or nurses.

Sore or red arm

The most common side effect following vaccination is a sore arm. If you use your arm normally after vaccination, it will help ease the soreness more quickly. In some people, vaccines may cause a lump or hardness at the injection site which persists for a few weeks. If your arm is red, hot and/or sore, place an ice pack over the affected area. You can take paracetamol. Intradermal vaccines (e.g. rabies) may cause itchiness at the injection site and a small surface lump which may persist for a few weeks. This is all part of a normal immune response to vaccination.

Can I drink alcohol after vaccines?

If taking typhoid capsules, alcohol (and food) must not be taken within a few hours of each capsule. However, it is OK to have alcohol after other vaccinations.

There is no evidence that drinking in moderation is harmful after most vaccinations.

In general, there are several reasons to avoid excess alcohol consumption after a vaccination. Excess alcohol consumption can potentially mask the side effects of the vaccine and make it difficult to determine which side effects are attributable to the vaccine or alcohol.

Excessive alcohol consumption on a regular basis may also affect your immune system. Research has shown that alcohol intake of 15 or more drinks per week for men and 8 for women may suppress the immune system along with other factors such as smoking, a lack of sleep and a poor diet.

If you do decide to drink following a vaccine, you should attempt to drink in moderation. If you are concerned about this, you should contact the doctor or nurse administering the vaccine to confirm the safety of alcohol intake following an upcoming vaccine.

Diarrhoea or stomach problems

The oral typhoid vaccine (capsules) may cause mild to moderate nausea, stomach cramps and diarrhoea within 12-24 hours after taking each capsule. If symptoms are more severe after the second capsule, please call our clinic and speak to one of our doctors or nurses.

Will vaccines weaken my immune system?

There is no evidence that vaccination weakens the immune system. In fact, vaccination is a very effective way of strengthening the immune system’s response to diseases. However, to avoid the risk of unnecessary side effects, vaccinations should only be recommended when there is a significant risk of disease.

How do I manage common vaccine side effects?

Many types of vaccines have similar mild side effects which can be managed at home. Common side effects include localised pain, swelling or redness at the injection site, fatigue, muscle or joint pain, weakness, mild fever, or chills.

These side effects indicate that your body is building immunity against the disease. To manage these side effects, over the counter painkillers and fever reducers such as paracetamol or ibuprofen can be taken.

Plenty of rest and hydration are recommended following a vaccine. Most side effects should last no longer than two days. If they last longer, contact your medical provider.

Serious reactions to vaccines occur extremely rarely. If you experience a life-threatening allergic reaction, such as swelling in the face, lips, tongue, throat, difficulties breathing or hives, get immediate emergency medical assistance.

What are the side effects of the flu vaccine?

Like any medical products or medicine, the flu vaccine can cause side effects. Common side effects include redness, warmth or swelling at the site of the injection, headaches, tiredness or body aches. Over the counter pain relievers such as ibuprofen or paracetamol can be used to reduce these symptoms.

Rarely, fainting or dizziness may be experienced. This can be relieved by resting during and after receiving the flu vaccine. A mild fever is also a rare side effect and can also be relieved by taking paracetamol or ibuprofen.

Side effects should not last any longer than two days. Contact the doctor or nurse who is administering the vaccine if you are concerned about post-flu shot side effects.

Importantly, as the flu vaccine is not a live vaccine it cannot give you the ‘flu’.

What are the side effects of the typhoid vaccine?

The typhoid vaccine is used to prevent typhoid fever, a serious potentially life-threatening illness caused by Salmonella Typhi bacteria. The vaccine is widely considered to be both safe and effective at preventing this illness. However, a range of side effects may be experienced following the vaccine.

Two types of typhoid vaccine are available: a live, attenuated (weakened) oral vaccine and an inactivated (killed) vaccine in the form of an injection.

Side effects for the injection typically include swelling, redness or pain at the injection spot, headache, fever and general discomfort. These side effects can be alleviated through rest, over the counter pain medications, and hydration.

Side effects for the oral typhoid vaccine may include mild loosening of the bowel motions, nausea,  and abdominal discomfort or cramping within 12-24 hours after each capsule is ingested. Very rarely people may have moderate diarrhoea or vomiting. Oral typhoid vaccine side effects can be minimised through hydration and rest. If these side effects become severe, contact a medical provider.

Side effects for both typhoid vaccines should not last for more than two days after receiving them. As with any vaccine or medication, there is a very small risk of developing a serious reaction. However, typhoid fever is far more dangerous to your health than the typhoid vaccine. If you have any questions about the typhoid vaccine, or its side effects, contact the medical provider who administered the vaccine to you.

Should I exercise after getting a vaccination?

Generally, it is safe to exercise after vaccinations. However, it may be prudent to avoid very strenuous exercise for a couple of hours after a vaccination. You may experience side effects that could inhibit your usual workout intensity such as local tenderness. If you develop other side effects such as fatigue or body aches in the several days after vaccination, this may also reduce your capacity to exercise. If this does occur, try a lighter exercise than usual, and make sure to listen to your body.

How long do vaccinations last?

The list below outlines the usual duration of protection once the vaccination course is complete. For some vaccines, the duration of protection is uncertain.

• Chickenpox – long-term
• Cholera (oral) - up to 2 years
• Diphtheria - 10 years
• Flu vaccine - up to 1 year
• Hepatitis A - Probable lifetime protection
• Hepatitis B - Lifetime
• Japanese B Encephalitis - 2 years to , depending on the vaccine used
• Measles, Mumps, Rubella - Life time
• Meningitis - new conjugate vaccines give up to 5 years protection
• Pneumonia - >5 years, probably life time
• Polio booster - Life time
• Rabies (pre exposure) - Immune memory persists for life; booster doses needed only
• Tetanus - 5-10 years
• Typhoid (injection) - up to 3 years
• Typhoid capsules x 3 - 3 years
• Typhoid capsules x 4 - 5 years
• Whooping cough – immunity begins to wane after 3-5 years
• Yellow Fever - Long-term; certificate valid for life
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Vaccination - Yellow fever

There's a very effective vaccine that can stop you getting yellow fever if you're travelling to an area where the infection is found.

It's given as an injection into your upper arm.

But even if you have been vaccinated, it's important to prevent insect bites  as mosquitoes can also spread other serious illnesses.

Who should have the yellow fever vaccine

The yellow fever vaccine is recommended for people from 9 months of age who are travelling to:

• an  area where yellow fever is found , including parts of sub-Saharan Africa, South America, Central America and Trinidad in the Caribbean
• a country that requires you to have a certificate proving you have been vaccinated against yellow fever

You should be vaccinated at least 10 days before you travel to allow enough time for the vaccine to work.

If you or your child has had the MMR vaccine , you or they need to wait at least 4 weeks before having the yellow fever vaccine.

If it is not possible to leave a 4-week gap, the yellow fever vaccine should be given but an additional dose of MMR should be considered at a later date. Re-vaccination with the yellow fever vaccine can also be considered on an individual basis for those at on-going risk.

Yellow fever vaccination certificate

Some countries require a certificate showing you have been vaccinated before you're allowed entry.

This is known as an International Certificate of Vaccination or Prophylaxis (ICVP).

All vaccination certificates are now valid for life, including older ones with an expiry date on them. You'll be given a certificate when you're vaccinated at a yellow fever vaccination centre.

Check the  country information  on the TravelHealthPro website or with a yellow fever vaccination centre to see if you need a certificate for the area you're visiting.

A certificate is not needed for entry into the UK.

Keep your certificate safe and make a copy for your records.

If you lose your certificate, you may be able to get another one reissued if you have a copy showing full details of the vaccination batch number and the date you had the vaccination.

Where to get the yellow fever vaccine

The yellow fever vaccine and vaccination certificates are only available from registered yellow fever vaccination centres.

Find a yellow fever vaccination centre near you

How much the yellow fever vaccine costs

The yellow fever vaccine is not available for free on the NHS, so you'll have to pay for it.

It typically costs around £60 to £85.

How long the yellow fever vaccine lasts

The yellow fever vaccine provides lifelong protection for most people.

A further dose of vaccine is recommended for a small number of travellers who are visiting yellow fever risk areas, including those who were previously vaccinated when they were:

• under 2 years old
• living with HIV
• had a weakened immune system
• before having a bone marrow transplant

Rarely, a further dose of vaccine may also be advised if there's a concern about the traveller's risk of yellow fever, for example, if they're working or living for some time in a high-risk area.

Contact a yellow fever vaccination centre for advice if you're not sure if you need another dose before travelling.

Who cannot have the yellow fever vaccine

There are some people who cannot have the yellow fever vaccine when it's recommended.

People who cannot have the vaccine include:

• babies under 6 months old
• people with a weakened immune system, such as those with leukaemia or lymphoma
• people whose immune system is weakened by treatment, such as steroids and chemotherapy
• people who are allergic to any of the ingredients in the vaccine, including people with an egg allergy
• people who've had a severe reaction to a previous dose of yellow fever vaccine
• people with a thymus gland disorder or who've had their thymus gland removed
• people over the age of 60 who are travelling to areas where yellow fever vaccine is not generally recommended
• people who have a close relative who has had a severe reaction to the vaccine causing damage to the brain or other organs

If you need a vaccination certificate for the country you're visiting but you're not able to have the vaccine, contact a yellow fever vaccination centre.

They may provide you with an exemption letter, which may be accepted by officials in countries that usually require a vaccination certificate.

Who may be able to have the vaccine in some circumstances

If you're not sure whether you can have the yellow fever vaccine, ask a travel health specialist at the vaccination centre. They'll do a full risk assessment based on your or your child's medical history and where you're travelling to.

People who may be able to have the vaccine include:

• those aged 60 and over – only when travel to a high-risk area is unavoidable
• those who are pregnant – if travel to a high-risk area is unavoidable
• those who are breastfeeding – expert advice is needed for women who are breastfeeding babies under 9 months
• those with long-term (chronic) inflammatory conditions, such as rheumatoid arthritis – if on low-dose steroid therapy
• babies from 6 months to under 9 months of age – if travel is unavoidable and risk is high, expert advice is needed
• those living with HIV – only after specialist advice

Take extra care to  prevent insect bites  while travelling if you have not been vaccinated.

Side effects of the yellow fever vaccine

The yellow fever vaccine can cause some side effects, but the risk of not being vaccinated usually outweighs the risk of having side effects.

After having the vaccine, up to 1 in every 3 people gets:

• a  headache
• muscle pain
• a raised temperature
• soreness at the injection site

These side effects usually pass within 2 weeks.

Rarely, a person can get more serious side effects, including an allergic reaction to one of the ingredients in the vaccine.

A very rare side effect of the vaccine can cause problems with the brain or other organs, which can be fatal. This is more likely to affect:

• people aged 60 or older
• people with weakened immune systems
• anyone who's had their thymus gland removed or has a thymus gland disorder

Get medical advice if you feel very unwell within a few days or weeks of having the yellow fever vaccine.

Page last reviewed: 25 July 2023 Next review due: 25 July 2026

Study Largely Confirms Known, Rare COVID-19 Vaccine Side Effects

By Kate Yandell

Posted on February 27, 2024

SciCheck Digest

An international study of around 99 million people confirmed known serious side effects of COVID-19 vaccination. It also identified a possible relationship between the first dose of the Moderna vaccine and a small risk of a neurological condition. Social media posts about the study left out information on the vaccines’ benefits and the rarity of the side effects.

More than  half a billion doses of COVID-19 vaccines have now been administered in the U.S. and only a few, very rare, safety concerns have emerged. The vast majority of people experience only minor, temporary side effects such as pain at the injection site, fatigue, headache, or muscle pain — or no side effects at all. As the Centers for Disease Control and Prevention has said , these vaccines “have undergone and will continue to undergo the most intensive safety monitoring in U.S. history.”

A small number of severe allergic reactions known as anaphylaxis, which are expected with any vaccine, have occurred with the authorized and approved COVID-19 vaccines. Fortunately, these reactions are rare, typically occur within minutes of inoculation and can be treated. Approximately 5 per million people vaccinated have experienced anaphylaxis after a COVID-19 vaccine, according  to the CDC.

To make sure serious allergic reactions can be identified and treated, all people receiving a vaccine should be observed for 15 minutes after getting a shot, and anyone who has experienced anaphylaxis or had any kind of immediate allergic reaction to any vaccine or injection in the past should be monitored for a half hour. People who have had a serious allergic reaction to a previous dose or one of the vaccine ingredients should not be immunized. Also, those who shouldn’t receive one type of COVID-19 vaccine should be monitored for 30 minutes after receiving a different type of vaccine.

There is evidence that the Pfizer/BioNTech and Moderna mRNA vaccines may rarely cause inflammation of the heart muscle (myocarditis) or of the surrounding lining (pericarditis), particularly in male adolescents and young adults .

Based on data collected through August 2021, the reporting rates of either condition in the U.S. are highest in males 16 to 17 years old after the second dose (105.9 cases per million doses of the Pfizer/BioNTech vaccine), followed by 12- to 15-year-old males (70.7 cases per million). The rate for 18- to 24-year-old males was 52.4 cases and 56.3 cases per million doses of Pfizer/BioNTech and Moderna vaccines, respectively.

Health officials have emphasized that vaccine-related myocarditis and pericarditis cases are rare and the benefits of vaccination still outweigh the risks. Early evidence suggests these myocarditis cases are less severe than typical ones. The CDC has also noted that most patients who were treated “responded well to medicine and rest and felt better quickly.”

The Johnson & Johnson vaccine has been linked to an  increased risk of rare blood clots combined with low levels of blood platelets, especially in women ages 30 to 49 . Early symptoms of the condition, which is known as thrombosis with thrombocytopenia syndrome, or TTS, can appear as late as three weeks after vaccination and  include  severe or persistent headaches or blurred vision, leg swelling, and easy bruising or tiny blood spots under the skin outside of the injection site.

According to the CDC, TTS has occurred in around 4 people per million doses administered. As of early April ,  the syndrome has been confirmed in 60 cases, including nine deaths, after more than 18.6 million doses of the J&J vaccine. Although TTS remains rare, because of the availability of mRNA vaccines, which are not associated with this serious side effect, the FDA on May 5 limited authorized use of the J&J vaccine to adults who either couldn’t get one of the other authorized or approved COVID-19 vaccines because of medical or access reasons, or only wanted a J&J vaccine for protection against the disease. Several months earlier, on Dec. 16, 2021 ,  the CDC had recommended the Pfizer/BioNTech and Moderna shots over J&J’s.

The J&J vaccine has also been linked to an increased risk of Guillain-Barré Syndrome, a rare disorder in which the immune system attacks nerve cells.  Most people  who develop GBS fully recover, although some have permanent nerve damage and the condition can be fatal.

Safety surveillance data suggest that compared with the mRNA vaccines, which have not been linked to GBS, the J&J vaccine is associated with 15.5 additional GBS cases per million doses of vaccine in the three weeks following vaccination. Most reported cases following J&J vaccination have occurred in men 50 years old and older.

Link to this

COVID-19 vaccines — like all  vaccines  and other medical products — come with side effects, including  serious side effects  in rare cases. The vaccines were rolled out to protect people from a novel virus that has  killed  millions of people globally and would likely have killed millions more without the arrival of the vaccines. There is a broad consensus from experts and governmental health agencies that the benefits of COVID-19 vaccination outweigh the risks.

Researchers have  scrutinized  the COVID-19 vaccines’ safety and continue to do so. A  study  published Feb. 12 in the journal Vaccine reported on an international group of more than 99 million people who received COVID-19 vaccines, primarily finding links to known rare side effects. The study largely focused on the Pfizer/BioNTech and Moderna vaccines, which have been  widely given  in the U.S., as well as the AstraZeneca vaccine, which was  never authorized  in the U.S.

“What we take away, is that the Covid-19 vaccination campaigns have been very effective in preventing severe disease,” study co-author  Anders Hviid , head of the department of epidemiology research at the Statens Serum Institut in Denmark, told us in an email. “The few serious side effects that we have observed in this and other studies have been rare.”

Many popular posts on social media have shared results from the study, some lacking the context that the identified  health problems are rare , that most aren’t new and that the vaccines have proven benefits. Various posts made unfounded claims, stating or implying that people should not have received the vaccines , that the risks outweigh the benefits or that the  risk of the rare side effects is greater than was reported in the study.

“Hundreds of millions of people were used as lab rats and now the truth that WE ALL ALREADY KNEW can no longer be denied,” said one popular  post , referring to the vaccines as “experimental” and “UNTESTED.” The post shared a screenshot of the headline of a New York Post  article  about the new study, which read, “COVID vaccines linked to slight increases in heart, brain, blood disorders: study.”

“This thing was forced on people who faced almost no risk from Covid,” said another widely read post . “It is completely unacceptable.” The post shared statistics from the paper without making it clear that serious health problems after vaccination were rare and that risk varied by vaccine type and dose.

The Vaccine study confirmed that the Moderna and Pfizer/BioNTech vaccines are linked in rare cases to myocarditis and pericarditis, conditions involving inflammation of the heart muscle and lining. The rate of myocarditis was most elevated after the second dose of the Moderna vaccine. Myocarditis risk — which is greatest in men in their late teens and early twenties — was  identified via vaccine safety monitoring and first reported in 2021. Based on the current evidence, the  CDC says, the benefit of vaccination outweighs the risk of these conditions, which improve for most people after medical treatment and rest.

The study confirmed neurological and blood clotting conditions associated with the AstraZeneca vaccine. In the U.S., these  problems  were  linked  to the Johnson & Johnson vaccine, contributing to this vaccine no longer being recommended or available.

The study also identified a new possible safety signal indicating a potential link between the first dose of the Moderna and AstraZeneca vaccines and rare neurological conditions. This included an association between the first doses of the vaccines and acute disseminated encephalomyelitis, or ADEM, an autoimmune condition that causes inflammation of the brain and spinal cord.

Hviid emphasized that the researchers only saw these neurological events after first doses of the two vaccines. “We did not see these signals following further doses of these two Covid-19 vaccines, nor did we see them after any dose of the Pfizer/BioNTech vaccine which has been more widely used,” he said.

“We are also talking about very rare events,” Hviid continued. “As an example, the association between the first dose of Moderna and acute inflammation of the brain and spine would, if causal, correspond to 1 case per 1.75 million vaccinated. It is only due to the sheer scale of our study, that we have been able to identify this minute potential risk.”

Study Bolsters the Evidence Serious COVID-19 Vaccine Side Effects Are Rare

The Vaccine  study  drew on national or regional health records from eight countries with institutions participating in the  Global Vaccine Data Network , an international group that studies vaccine safety. The researchers analyzed health outcomes after around 184 million doses of the Pfizer/BioNTech vaccine, 36 million doses of the Moderna vaccine and 23 million doses of the AstraZeneca vaccine. 

The researchers focused on 13 health problems that either had a known association with vaccination or for which there was some rationale to investigate whether there was an association. To determine whether the health problems were associated with vaccination, they compared the expected rates of the health problems — or the number of health events that should occur based on background rates in the regions studied — with the number of events they observed in the 42 days after vaccination.

“This study confirms the primary already detected and validated side effects established by previous literature,”  Jeffrey S. Morris , director of the division of biostatistics at the University of Pennsylvania’s Perelman School of Medicine, told us via email, referring to the rare heart conditions associated with the Moderna and Pfizer/BioNTech vaccines, as well as the rare conditions associated with the AstraZeneca and Johnson & Johnson vaccines. 

Morris said that findings on ADEM — the rare autoimmune neurological condition linked to first doses of the Moderna and AstraZeneca vaccines — “might be a new safety signal.” 

ADEM  involves  inflammation to the brain and spinal cord, arising most often in children following an infectious illness. It has a  sudden onset  and typically eventually improves, with a full recovery in many, although not all, cases.

After the first dose of the Moderna vaccine, researchers observed seven ADEM cases, when they expected two. As we’ve said, Hviid calculated the rate of this side effect — if ultimately shown to be related to vaccination — to be 1 in 1.75 million following the first dose of the Moderna vaccine. 

The data show “this was indeed an EXTREMELY rare adverse event,” Morris said, referring to ADEM. “It is understandable at this incidence rate why it may not have been detected before now, and why a study with 99 million participants like this is important to find even the most rare serious adverse events that are potential minority harm risks of these vaccines.”

The authors of the study wrote that more research is needed into ADEM following COVID-19 vaccination, saying that “the number of cases of this rare event were small and the confidence interval wide, so results should be interpreted with caution and confirmed in future studies.” The authors also wrote that neurological  events  have been found to occur at a much higher rate after COVID-19 than after COVID-19 vaccination.

The study means that “early warning systems are solid,” said  Marc Veldhoen , an immunologist at the Instituto de Medicina Molecular João Lobo Antunes in Portugal, in a  post  on X, formerly known as Twitter. “To avoid any adverse reaction is not possible, but, identifying those at higher risk may be possible.”

Identifying those at greater risk of side effects can help guide decisions on which vaccines to recommend and what problems doctors should watch for in their patients.

Editor’s note: SciCheck’s articles providing accurate health information and correcting health misinformation are made possible by a grant from the Robert Wood Johnson Foundation. The foundation has no control over FactCheck.org’s editorial decisions, and the views expressed in our articles do not necessarily reflect the views of the foundation.

“ How do we know vaccines are safe? ” FactCheck.org. Updated 8 Jul 2021.

“ Selected Adverse Events Reported after COVID-19 Vaccination .” CDC website. Updated 12 Sep 2023.

Yandell, Kate. “ Tucker Carlson Video Spreads Falsehoods on COVID-19 Vaccines, WHO Accord .” FactCheck.org. 13 Jan 2024.

“ Safety of COVID-19 Vaccines .” CDC website. 3 Nov 2023.

“ How safe are the COVID-19 vaccines? ” FactCheck.org. Updated 17 May 2022.

Faksova, K. et al. “ COVID-19 Vaccines and Adverse Events of Special Interest: A Multinational Global Vaccine Data Network (GVDN) Cohort Study of 99 Million Vaccinated Individuals .” Vaccine. 12 Feb 2024.

COVID Data Tracker. “ COVID-19 Vaccinations in the United States .” CDC website. Updated 11 May 2023.

Liu, Angus. “ AstraZeneca withdraws US COVID vaccine application, shifts focus to antibody treatments .” Fierce Pharma. 10 Nov 2022.

Hviid, Anders. Email with FactCheck.org. 22 Feb 2024.

TheBlaze. “ Blood clots, neurological disorders, and swollen hearts: Multinational study on COVID vaccines paints a damning picture .” Facebook. 20 Feb 2024.

Dr. Anthony G. Jay (@anthonygjay). “ I post a lot of vids but rarely PLUG them WATCH my YouTube vid on this – it’s 6 minutes – before it gets taken down 🤐 .” Instagram. 20 Feb 2024.

bikinibottom_fish 🐟 (@bikinibottom_fish). “ Global Study Links COVID-19 Vaccines to Heart and Brain Issues! ” Instagram. 20 Feb 2024.

PatrioticBabe 🇺🇸 (@babedoesthenews). “ ❗️ .” Instagram. 20 Feb 2024.

RASPY RAWLS (@raspy_rawls2). “ … We told yall not to take that shyt but hey wat dew we know 🤷🏾‍♂️ …  .” Instagram. 20 Feb 2024.

Jaimee Michell (@thegaywhostrayed). “ I want to know if you think Trump holds any blame, and if not, why not? COMMENT your thoughts BELOW! ” Instagram. 20 Feb 2024.

Liberty Counsel (@libertycounsel). “ …  “Based on ‘conservative assumptions,’ the estimated harms of the COVID-19 mRNA vaccines ‘greatly outweigh the rewards,’ the article stated, noting that ‘for every life saved, there were nearly 14 times more deaths caused by the modified mRNA injections.’” … ” Instagram. 20 Feb 2024.

Shemeka Michelle (@ theshemekamichelle ). “ Remember when they called them “rare” breakthrough cases? Yeah, me too. #slight .” Instagram. 20 Feb 2024.

Mal’aki (@awake.the.mind). “ ‘Slight’ will turn to ‘significant’ soon enough. We tried to warn you all but we’re just crazy conspiracy theorists .” Instagram. 20 Feb 2024.

Steinbuch, Yaron. “ COVID vaccines linked to slight increases in heart, brain, blood disorders: study .” New York Post. 20 Feb 2024.

Vogel, Gretchen and Couzin-Frankel, Jennifer. “ Israel reports link between rare cases of heart inflammation and COVID-19 vaccination in young men .” Science. 1 Jun 2021.

Robertson, Lori and Kiely, Eugene. “ Q&A on the Rare Clotting Events That Caused the J&J Pause .” FactCheck.org. Updated 6 May 2022.

Kahn, Ilana. “ Acute Transverse Myelitis and Acute Disseminated Encephalomyelitis .” Pediatrics in Review. 1 Jul 2020.

Morgan, Hannah J. et al. “ Acute Disseminated Encephalomyelitis and Transverse Myelitis Following COVID-19 Vaccination – A Self-Controlled Case Series Analysis .” Vaccine. 12 Feb 2024. 

“ Global COVID Vaccine Safety (GCoVS) .” Global Vaccine Data Network website. Accessed 23 Feb 2024.

Morris, Jeffrey S. Email with FactCheck.org. 22 Feb 2024.

Frontera, Jennifer A. et al. “ Neurological Events Reported after COVID-19 Vaccines: An Analysis of VAERS .” Annals of Neurology. 2 Mar 2022.

Marc Veldhoen (@Marc_Veld). “ COVID-19 vaccines and adverse events of special interest: A multinational Global Vaccine Data Network (GVDN) cohort study of 99 million vaccinated individuals Anything in those anti-vax stories about large scale damage and deaths due to vaccines? No. … ” X. 19 Feb 2024.

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Do you need to worry about side effects from vaccines?

Peer reviewed by Dr Sarah Jarvis MBE, FRCGP Last updated by Abi Millar Last updated 13 Dec 2019

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Like all medical treatments, vaccinations carry risks as well as benefits. But with scare stories abounding on social media, should you be concerned about possible side effects?

In this article :

What are the risks of getting vaccinated, what are the chances of serious side effects, multiple vaccines - double the trouble.

It should go without saying that vaccinations are a crucial part of staying healthy. Whether we're talking about routine injections in childhood, or travel jabs before you go abroad, vaccinations can protect you against any number of potentially deadly diseases. Importantly, since you won't be able to pass on those diseases, it also protects those around you.

Unfortunately, getting the facts right about vaccinations can mean sifting through a lot of misinformation. This year, the UK saw a sharp rise in cases of measles , which public health experts have linked to a drop in the number of children receiving the MMR jab (for measles, mumps and rubella ).

They suggested the drop might be due, to a large extent, to 'anti-vaxxer' myths on discussion boards. One of these is the idea that the MMR vaccine causes autism . While this theory has been thoroughly and repeatedly debunked , it continues to rear its head on social media.

As Gino Martini, chief scientist at the Royal Pharmaceutical Society points out, this trend is extremely worrying.

"How many of the people on the discussion forums are actually medical doctors with the right advice?" he says. "We're getting into a situation where people aren't getting the information. People go on Facebook and have conversations, and suddenly they aren't vaccinating anymore. This is important because the diseases we're trying to prevent are very nasty."

While vaccinations can cause side effects, these effects are typically very mild, and the risks associated with contracting the disease far outweigh the risks of getting vaccinated.

"You might experience cold -like symptoms, a high temperature , or aches and pains," says Martini. "Those are the kinds of adverse events you see while your body adapts to the vaccination. You may also experience some pain at the site of administration."

Vaccines work by introducing a small amount of bacteria, virus or toxin into the body. Because the bacteria, virus or toxin have been killed or weakened, there's no risk of contracting the disease in question. However, your body responds as if it were under attack, and mounts an immune response. If, in the future, you do encounter that disease, you'll have an army of antibodies ready to fight it.

This means that any adverse effects you experience are unlikely to be caused by the bacteria, virus or toxin. Most of the common side effects (such as a sore arm or redness) are caused by the injection, or by your own immune system fighting against the weakened invaders.

The risk of even mild allergic reaction to the vaccine is small. In this case, you're more likely to be reacting to one of the added ingredients than to the virus. The person administering the jab will ask you about allergies first - egg protein and pork gelatine are possible culprits.

Serious adverse events, while possible, are very rare - and they tend to make the news precisely because they're so unusual. You may have read reports last year about two people who died after receiving the yellow fever vaccination . If you're considering getting the jab, this tragic news needs to be viewed in context.

According to the World Health Organization , serious side effects occur at a rate of around 0.09 to 0.4 cases per 10,000 doses of the yellow fever vaccine, in populations who haven't been exposed to the virus. By contrast, the serious form of yellow fever is fatal around half the time.

On a similar note, the rate of serious allergic reaction is around 1-2 cases per million across all vaccines. Compare that with the death rate for measles (around 1 in 500), and for flu (around 200 deaths in the UK every winter), and it's obvious which is riskier.

"What we need to understand are the risks and benefits - how many people are dying from yellow fever, how many people are dying from measles?" says Martini. "Clearly, adverse effects are tragic for the individual and the family but they are rare, and we need to balance this with the risks associated with that disease."

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Another important question is what happens when you get multiple vaccinations. If you're going travelling, for example, you may need five or more injections at once. And in the UK, a two-month-old baby will receive the PCV , Rotavirus , 6-in-1 and MenB vaccines on the same visit.

Of course, being injected isn't fun, and being repeatedly injected is even less fun. Your arm may be sorer than it would be with a single vaccine. And if you start to feel unwell during any point in the process, you should stop and seek advice from the person administering the vaccine.

However, you don't need to worry about some kind of compound side effect, or overloading the immune system . Even a baby's immune system is well equipped to cope, and is exposed to many times more antigens every day than those contained in any vaccine - multiple or otherwise. Avoiding multiple or combination vaccines will only draw out the process.

If you're still on the fence, it's important to remember that vaccinations prevent up to three million deaths worldwide every year, and the introduction of vaccination programmes has wiped out many diseases that used to be killers.

On top of that, your pharmacist, nurse or doctor should be able to help you with any concerns that arise. As Martini explains, they're there to put your mind at rest, and walk you through what to expect, This will always include information about possible side effects.

"If you’re worried, the first port of call is always to talk to the pharmacist or nurse. They'll be able to advise you," he says. "They'll look at the vaccine and the manufacturer's advice, because it's information that can help the patient and reassure them."

Article history

The information on this page is peer reviewed by qualified clinicians.

13 Dec 2019 | Latest version

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