Most travel vaccines cause mild, short-lived side effects like a sore arm, low fever, or fatigue. These reactions are normal and typically clear within 24 to 48 hours. Serious side effects are genuinely rare. But knowing what to watch for, vaccine by vaccine, makes the whole experience far less stressful. 

Read on for a clear breakdown of what each jab can cause and exactly what to do about it. For personalised advice before your trip, you can also visit our travel clinic for guidance on the vaccines you may need.

Why Do Travel Vaccines Cause Side Effects?

When you receive a vaccine, your immune system treats it as a threat. It mounts a response, and that response is what produces the mild symptoms people mistake for the vaccine “making them ill.”

A slightly sore arm or a day of fatigue isn’t something going wrong. It’s your body building the antibodies that will protect you overseas. The short-term discomfort is, in almost every case, far preferable to catching typhoid on a trip.

Specific Side Effects by Travel Vaccine

Keep these subsections scannable and fact-based so the reader can quickly find their specific shot.

Yellow Fever

Yellow fever is a live vaccine, which means the side effect timeline is different from most others. Reactions tend to appear 3 to 7 days after the injection, not immediately.

Common side effects include mild fever, headache, muscle aches, and fatigue. Serious reactions are rare but real: yellow fever vaccine-associated neurological disease (YEL-AND) and yellow fever vaccine-associated viscerotropic disease (YEL-AVD) occur in roughly 1 to 2 per 100,000 doses, mainly in those over 60 or those with thymus disorders.

Always check your suitability before booking this vaccine, especially if you are immunocompromised.

Typhoid (Pill vs. Injection)

The injectable typhoid vaccine (inactivated) typically causes arm soreness and, occasionally, a low-grade fever for a day or two. The oral Ty21a vaccine (taken as three capsules on alternate days) tends to produce fewer systemic effects but may cause mild stomach upset, nausea, or loose stools in some people.

The injection is generally better tolerated overall. If you have a sensitive stomach, it’s worth discussing which form suits you best.

Hepatitis A and Hepatitis B

Hepatitis A is one of the most straightforward travel jabs in terms of tolerability. Arm soreness at the injection site is the most reported effect, affecting roughly 50% of recipients. Fatigue and a mild headache can occur but usually pass within a day.

Hepatitis B follows a similar pattern, though some people notice more pronounced fatigue after the second or third dose in the series. Combining both into a single Twinrix injection does not appear to increase the rate or severity of side effects.

Rabies (Pre-Exposure)

Pre-exposure rabies vaccination involves three injections over 21 to 28 days. Arm soreness and mild redness at the injection site are common, particularly after the second dose.

Systemic effects such as headache, dizziness, and muscle aches occur in a minority of recipients. Serious reactions are extremely uncommon. Most people complete the course without significant disruption to their daily routine.

Cholera (Oral Vaccine)

The Dukoral cholera vaccine is taken as a drink, mixed with a bicarbonate solution. The most frequently reported side effects are gastrointestinal: mild stomach cramps, nausea, and occasionally diarrhoea.

These tend to appear within hours of taking the dose and resolve quickly. Systemic reactions like fever are uncommon. The drink itself has a slightly salty taste, which some people find unpleasant but manageable.

Japanese Encephalitis

Japanese encephalitis (JE) vaccine, given as two doses, has a reputation for delayed reactions. Mild arm soreness and redness are typical, but fatigue and headache can appear anywhere from a few hours to a few days post-injection.

Hypersensitivity reactions, including urticaria (hives) and facial swelling, have been reported in a small percentage of recipients, usually within 10 days of the dose. For this reason, it’s recommended you avoid strenuous exercise and alcohol for 48 hours after each dose, particularly if you have a history of allergies.

Meningitis ACWY

This is generally a very well-tolerated vaccine. Localised redness and arm soreness are the most common complaints, typically settling within 24 hours.

A mild fever and fatigue can occur, mostly in younger adults. There is no live component in this vaccine, so the reaction window is short and predictable.

Rare But Serious Side Effects

Anaphylaxis following a travel vaccine is estimated at roughly 1 in a million doses. It is serious, but it is also manageable precisely because vaccines are given in a clinical setting where trained staff carry adrenaline.

This is exactly why you should stay in the clinic or pharmacy for at least 15 minutes after any vaccination. Anaphylaxis typically presents within minutes of the injection, not hours later. If a reaction begins after you’ve left, call 999 immediately.

How Long Do Vaccine Side Effects Last?

For most inactivated vaccines (typhoid injection, hepatitis A and B, rabies, meningitis ACWY), the 24 to 48 hour rule applies. Side effects begin within a few hours of the jab and are largely gone within two days.

Live vaccines follow a different pattern. Yellow fever, for example, may not produce symptoms until 3 to 7 days after the injection, and those symptoms can last a few days once they start. Plan your yellow fever vaccination at least 10 days before travel, both for protection to take effect and to allow time to recover from any reaction.

How to Manage Vaccine Side Effects at Home

For a sore arm: Keep the arm moving. Gentle movement increases blood flow and helps disperse the vaccine fluid from the injection site. Apply a cool, damp cloth to reduce localised swelling and discomfort.

For fever and fatigue: Drink plenty of water. Rest if you need to. Take ibuprofen or paracetamol after the vaccination if symptoms develop, not before. Taking pain relief pre-emptively before your jab may blunt your immune response, which is counterproductive.

What to avoid: Alcohol and intense exercise in the 24 to 48 hours following vaccination can worsen systemic symptoms. With the Japanese encephalitis vaccine specifically, avoid both for the full 48 hours after each dose.

Normal vs. Abnormal: When to Seek Medical Attention

Normal reactions (no action needed beyond rest):

• Sore, red, or slightly swollen arm at the injection site
• Low-grade fever (below 38.5°C)
• Fatigue or mild headache
• Nausea after an oral vaccine
• Muscle aches for 1 to 2 days

Go to A&E or call 999 immediately if you experience:

• Difficulty breathing or wheezing
• Swelling of the face, lips, or throat
• A racing or irregular heartbeat
• Fainting or sudden dizziness
• A fever above 39°C that does not come down with paracetamol
• A rash spreading rapidly across the body

These symptoms, though rare, are medical emergencies. Do not wait to see if they pass.

Concerned about a vaccine reaction? Contact us directly and one of our pharmacists will advise you on your next steps.

Frequently Asked Questions

Can I get travel vaccines if I’m currently taking antibiotics?

Antibiotics do not affect inactivated travel vaccines. If you’re due to take the oral typhoid or cholera vaccine, antibiotics can interfere with their effectiveness, so timing matters.

Should I tell the pharmacist if I had a reaction to a previous vaccine?

Yes, always. A prior reaction, even a mild one like an unusual rash, should be disclosed before any subsequent vaccination so the correct precautions can be taken.

Do travel vaccines affect the results of blood tests or medical screenings?

Some vaccines, particularly yellow fever, can temporarily elevate certain inflammatory markers. If you have a scheduled blood test within a week or two of vaccination, inform the requesting clinician.

Can children and older adults experience more severe side effects from travel vaccines?

Older adults, particularly those over 60, carry a marginally higher risk of serious reactions with yellow fever vaccine. Children may run higher fevers in response to some vaccines but generally tolerate travel jabs well.

Is it safe to have multiple travel vaccines on the same day?

Most travel vaccines can be given simultaneously without increasing adverse effects. Live vaccines that cannot be given together (such as yellow fever and the MMR) should be separated by at least four weeks.

Conclusion

Travel vaccine side effects are, in the vast majority of cases, mild, short-lived, and manageable at home. A sore arm and a day of fatigue are not reasons to skip the jabs that could protect you from diseases like rabies, typhoid, or yellow fever.

Understanding the timeline specific to each vaccine, knowing which symptoms are normal, and knowing the warning signs that need immediate attention puts you in a much stronger position. Keep moving the arm, drink water, take pain relief after (not before), and rest if you need to.

And if anything feels off in the hours or days after vaccination, reach out to your pharmacist. That’s exactly what we’re here for.