Immunisation

Immunisation (getting vaccinated) is the most effective way to prevent infectious disease and ill health. It provides protection to everyone, by helping to stop the spread of diseases.

How vaccination works

Millions of deaths are saved each year worldwide because people have been vaccinated. Some diseases can be eradicated if enough people get vaccinated because it is harder for the disease to spread.

A vaccine teaches the body’s immune system how to create antibodies to give protection against a disease.

The main ingredient of a vaccine is a small amount of bacteria, virus or toxin that has already been destroyed or weakened. It is therefore not possible to get the disease from the vaccine.

Allergies and side effects

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.

Testing and 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.

UK immunisation programme

The UK immunisation programme highlights the importance of vaccination uptake for vaccine preventable diseases, recommendation as follows:

Childhood immunisation (birth to 14 years)

Young adults immunisation

Adults immunisation (18+ years)

People at risk (all ages)

Covid-19 immunisations (all ages)

To find out who can currently get COVID vaccines and when, visit NHS - Coronavirus vaccines.

Further information

• Herd immunity - Oxford University
• Medicines and Healthcare Products Regulatory Agency (MHRA) - GOV.UK
• Report a vaccination side effect - Yellow Card Scheme
• Vaccination tips for parents - NHS

Last updated 12 February 2024