It's natural to be concerned that you or your child will have a side effect after having a vaccination.
While all vaccines have the potential to cause side effects in some people, the reality is that most tend to be mild and don't last longer than a few days. Some people don't get any side effects at all.
Common vaccine side effects
Common side effects of any vaccine can include:
- injection site reactions (pain, swelling and redness)
- mild fever
- muscle and joint pain
Rare vaccine side effects
A far less common, but serious, vaccine side effect is an immediate allergic reaction, also known as an anaphylactic reaction.
These are dramatic and potentially life-threatening. However, they are very rare - occurring in less than one in a million cases - and are completely reversible if treated promptly by healthcare staff.
To have a balanced view, potential side effects have to be weighed against the expected benefits of vaccination in preventing the serious complications of disease.
Read more about the benefits and risks of vaccination.
Not all illnesses that occur after vaccination will be a side effect. Because millions of people every year are vaccinated, it's inevitable that some will go on to develop a coincidental infection or illness shortly afterwards.
What to do if your child is unwell after having a vaccination
Most common side effects in babies and young children are at the site of the injection, and include:
- a small hard lump
These symptoms usually pass within a couple of days and you don't need to do anything about them.
Children may sometimes develop a high temperature (fever). If this happens, keep your child cool.
Make sure they don't wear too many layers of clothes or blankets and give them plenty of cool drinks. You can also give them a dose of infant paracetamol or ibuprofen liquid according to the instructions on the bottle.
Read an NHS leaflet about the common side effects of vaccinations that may occur in babies and children under the age of five (PDF, 118kb), and how to treat them.
Find out about a vaccine's side effects
A patient information leaflet (PIL) is included in the pack of each dose of vaccine, and lists its potential side effects.
You can also read vaccine PILs online on the electronic Medicines Compendium (eMC) website.
Reporting a vaccine side effect
If you, a doctor, nurse or pharmacist suspects that you or your child has had a possible side effect to a vaccine, it can be reported through the Yellow Card Scheme.
The Yellow Card Scheme is run by the Medicines and Healthcare products Regulatory Agency (MHRA) and is designed to pick up unexpected problems or new side effects.
If a serious new side effect is identified, the MHRA will follow up the report. It may change the way a vaccine is used, or it may even be taken off the market.
How to use the Yellow Card Scheme
Tell your doctor, nurse or pharmacist about the suspected side effect, and they'll report it for you. Alternatively, you can report it yourself by:
- using the Yellow Card Scheme online reporting system
- picking up a Yellow Card form at your GP surgery or local pharmacy - complete the form and send it to the address provided
- calling the Yellow Card freephone hotline on 0808 100 3352, Monday to Friday, 10am to 2pm
Now, read more about the safety of vaccinations, or about the side effects of each vaccine:
- side effects of the 6-in-1 infant vaccine
- side effects of the 4-in-1 pre-school booster
- side effects of the 3-in-1 teenage booster
- side effects of the MMR vaccine
- side effects of the chickenpox vaccine
- side effects of the Men C vaccine
- side effects of the Men B vaccine
- side effects of the Men ACWY vaccine
- side effects of the Hib/Men C booster
- side effects of the pneumococcal vaccine
- side effects of the HPV (cervical cancer) vaccine
- side effects of the BCG vaccine
- side effects of the flu vaccine
- side effects of the children's flu vaccine
- side effects of the rotavirus vaccine
- side effects of the shingles vaccine
Article provided by NHS Choices