Risks and benefits

All medicines have side effects. However, vaccines are among the safest and the benefits of vaccinations far outweigh the risk of side effects.

When we're considering a vaccination for ourselves or our children, it's natural to think about the potential side effects. What you need to do is balance the risks against the benefits.

What are the side effects of vaccination?

Most side effects from vaccination are mild and short-lived. It's quite common to have redness or swelling around the injection site, but this soon goes away. Younger children or babies may be a bit irritable or unwell, or have a slight temperature. Again, this usually goes away within one or two days.

Find out how to report a side effect of a vaccination.

In much rarer cases, some people have an allergic reaction soon after a vaccination. This is usually a rash or itching that affects part or all of the body. The GPs and nurses who give the vaccine are trained in how to treat this.

On very rare occasions, a severe allergic reaction may happen within a few minutes of the vaccination. This is called an anaphylactic reaction. It can lead to breathing difficulties and, in some cases, collapse.

Remember that anaphylactic reactions are extremely rare (fewer than one in a million). Vaccination staff are trained to deal with this, and these reactions are completely reversible if treated promptly.

Vaccination versus medicine

Vaccination is different from giving medicine to an unwell child to make them better. The benefits of vaccination are invisible. Your child won't become ill with measles or end up in intensive care with meningitis C.

It may be tempting to say "no" to vaccination and "leave it to nature". However, deciding not to vaccinate your child puts them at risk of catching a range of potentially serious, even fatal, diseases.

In reality, having a vaccination is much safer than not having one. They're not 100% effective in every child, but they're the best defence against the epidemics that used to kill or permanently disable millions of children and adults.

Read more about the safety of vaccinations.

Last Updated: 17/02/2022 16:07:19
The information on this page has been adapted by NHS Wales from original content supplied by NHS website nhs.uk