At a glance
When travelling to certain countries, vaccination is recommended or mandatory. What are the most common side effects of these vaccines?
When travelling or heading to certain countries, it is recommended or mandatory to get vaccinated. However, many travellers fear the possible side effects of these vaccines or preventive measures. Is this caution really justified? What are the most common side effects?
Side effects that are usually mild and temporary
Usually, the side effects of a vaccination are limited to pain at the injection site and a slight fever. When these symptoms appear, some people think they've been infected by the vaccine, when in fact it's a normal reaction of the body.
A small number of people may, however, show stronger reactions, such as allergic reactions.
As a rule, having several vaccinations at the same time doesn't affect the severity of side effects.
The main thing, then, is to recognise the symptoms of a serious reaction so that the right measures can be taken quickly.
The most common symptoms of serious side effects
A serious reaction can show up as various symptoms: e.g. the person suffers from a high fever, breathing problems, a strong skin reaction, behavioural changes, a fast heart rate, dizziness, or gastrointestinal issues (diarrhoea).
If this is the case, a visit to a doctor or emergency services is needed as soon as possible. During your consultation, explain in as much detail as possible when the injection took place or when the treatment started, which injection or medication is involved, and what symptoms appeared.
What side effects for which vaccinations?
Hepatitis A
- mild pain at the injection site, sometimes headaches, loss of appetite and/or temporary tiredness.
- more rarely: gastrointestinal problems, mild fever (up to 38.5°), dizziness.
Hepatitis B
- mild pain at the injection site, mild fever, tiredness.
- more rarely: a more serious allergic side effect (see the paragraph above). In this case, consult your doctor.
Yellow fever
- mild pain at the injection site, aches, headaches.
- more rarely: (high) fever, numbness in the arms and legs, fainting. In this case, consult your doctor.
Meningococcal meningitis
- mild pain at the injection site.
- more rarely: mild fever.
Diphtheria, tetanus, polio-whooping cough
- mild pain and swelling at the injection site, mild fever, sometimes loss of appetite and nausea.
- more rarely: convulsions, high fever (40° and above), headaches, breathing difficulties. These strong reactions are rare. In this case, consult your doctor immediately.
Flu
- mild pain at the injection site and skin reaction, mild fever.
- serious side effects are very rare (in which case they involve allergic reactions or breathing difficulties).
Side effects in young children
Babies and young children often react more strongly to medication and vaccinations.
Side effects generally affect the injection site and show up as a skin reaction (redness), mild numbness in the limb where the injection was given and/or a mild fever.
As the child will feel some (mild) pain, they will often react by crying and/or saying it hurts. Most of the time, these mild effects fade and disappear after 48 hours.
In any case, a young child who has had a vaccination must be watched very closely. Don't take any risks if you notice that the side effects persist or get worse. Contact your doctor immediately.
Malaria: no vaccine, but medication
Travellers heading to places where malaria poses an endemic risk can protect themselves by taking medication. These are only available on prescription. Consult your doctor before you leave. They will prescribe malaria treatment (chemoprophylaxis) suited to your destination as well as the duration and type of trip you plan to take. They will also take into account your sensitivity to the treatment and any possible side effects.
The substances most commonly used to treat malaria are quinine, chloroquine, doxycycline, mefloquine or proguanil, and the best-known medicines are Nivaquine®, Malarone®, Lariam®, Paludrine® and Savarine®.
Treatment starts before you leave and continues for up to 4 weeks after your return.
Side effects can vary widely depending on the type of medication prescribed and how your body reacts. Some of these unwanted effects can last several weeks.
The most common side effects are stomach aches, headaches, nausea, vomiting or gastrointestinal problems (diarrhoea).
A medication such as Lariam® has the advantage of only needing to be taken once a week, but has serious or severe side effects in a larger number of people.
Other medications such as Malarone® are usually more suited to shorter stays. The same goes for doxycycline (an antibiotic).
In any case, consult your doctor and follow the treatment carefully.
Where can you get vaccinated?
The website of the Antwerp Institute of Tropical Medicine can inform you about vaccinations by travel destination. The institute also has an app called Wanda, which lets travellers get information, stay up to date on health and medical risks by country, and find vaccination centres.
You'll find the information here.
