Immunisation safety

Evidence shows it is safer to get vaccinated, than not to be. It is much safer for the immune system to learn to do this through vaccination than to catch the disease. Some vaccines can give protection for many years.

All vaccines go through rigorous testing before they are introduced and continue to be monitored afterwards by the MHRA. Vaccines do not weaken or overload the immune system, even if more than one vaccination is given at any one time, and there is no evidence of links between vaccination and allergies or other conditions. 

Anti-vaccine stories tend to be found online on social media channels but are not usually based on any scientific evidence. It is important to speak to a GP or healthcare professional or look at official sources to get accurate information about the vaccine.

Vaccine hesitancy, where people with access to vaccines delay or refuse vaccination, is one of the biggest threats to everyone’s health. 

It is important that everyone receives their vaccinations when they are due, so they are fully protected. If you or your child has missed any vaccines, speak to your GP to discuss how it can be arranged.


A few people may not be able to get vaccinated. This could include people who have:

  • a weakened immune system, because of treatment for an existing condition
  • had a serious reaction to a previous dose of the vaccine

Some people may be allergic to an ingredient in the vaccine, but there is often an alternative vaccination which contain different ingredients. If others get vaccinated, anyone who is unable to will also be protected from the disease.

Occasionally when a vaccine is given there can be some side effects. The most common is a slight fever and the area where the vaccine was given feeling a bit sore. However, not everyone experiences effects, and they often do not last for more than a few days.

Last updated 31 May 2023