Vaccine safety and side effects

As with any medicine, vaccines may trigger side effects in some people. Side effects are usually mild and short-lived. They are also rare, and authorised vaccines are considered very safe. However, some vaccines may not be appropriate for some people with allergies or certain health conditions. 

Side effects

Vaccine side effects can include mild fever or pain or redness at the injection site. Serious side effects are very rare. 

After a vaccine is approved for use in the EU/EEA, the European Medicines Agency (EMA) and national authorities continually monitor whether people who have received the vaccine experience any side effects.

For more information about vaccine side effects, see: 

When not to get vaccinated

Some people are unable to get vaccinated due to their specific health circumstances. If they have been told they have a  contraindication for a specific vaccine by their healthcare provider, they should not get vaccinated with that particular vaccine. A contraindication is a condition or circumstance that makes it unsafe for someone to receive a specific vaccine. In such cases, the risks of getting vaccinated outweigh the benefits.

Allergic reactions

One common reason not to get vaccinated is due an allergy to any of the active substances or ingredients in the vaccine. If a person has had an extreme reaction causing shock, swelling and difficulty breathing (anaphylaxis) to a vaccine in the past, they should not receive that vaccine again unless it has been definitively ruled out as the cause.

Other contraindications

Certain medical conditions or treatments can also be contraindications for some vaccines. For example, people with immune system disorders or who are getting specific medical treatments may not be able to receive certain vaccines, such as measles, mumps, rubella, varicella, or oral typhoid.

People with weakened immune systems can benefit from those around them being fully vaccinated, as then they are indirectly protected.

There may be other contraindications for specific vaccines, which should be discussed with healthcare providers.

Vaccines and pregnancy

It is also important to know that some vaccines are not recommended during pregnancy. For example, measles, mumps, and rubella vaccines should be avoided during pregnancy. Women should receive all routinely recommended vaccines before they reach reproductive age. Before getting vaccinated, they should inform their healthcare provider if they could be pregnant to discuss which vaccines can be given during and after pregnancy.