How does the flu vaccine work?
Vaccines work by stimulating our own body’s immune system to produce substances (antibodies) in the body to fight disease without us actually becoming infected with the disease.
Once the body has produced these antibodies, it remembers how to make them and can quickly deal with that virus in the future and stop it at an early stage – this is what is called immunity. Flu vaccine contains viruses that are inactivated so that they don’t cause illness, but will still trigger your immune system to produce the right antibodies, giving you immunity against those viruses.
There are also small quantities of preservatives in the vaccine, and sometimes an ‘adjuvant’ that boosts your immune system to respond to the viruses.
Flu vaccine contains particles of inactivated flu viruses, chosen to give the most up-to-date protection possible. These usually include two different ‘A’ strains and one ‘B’ strain. The 2010/11 seasonal flu vaccination includes a vaccine to protect against swine flu, which is the virus that caused the swine flu pandemic during 2009.
When should you have the flu vaccine?
The seasonal flu vaccine is offered free of charge to all ‘over 65’s’ and those people who are at greater risk of developing further health complications if they contract flu. For the full list of ‘at risk’ groups click here.
If you are within an ‘at risk’ group, you should have a flu vaccine every year to make sure you are protected against the latest strains of influenza. The virus strains in each year’s flu vaccine are chosen by the World Health Organisation (WHO), which keeps checks on which viruses are most common in the population and likely to cause an epidemic. Flu viruses are constantly changing, so you need to keep your protection updated.
Does the flu vaccine have any side-effects?
Flu vaccine contains inactivated virus particles, which cannot give you flu but may cause a slight temperature and some aching muscles, and you may have slight soreness at the injection site.
Before any vaccine is given, please inform your doctor or nurse if you or your child have had any previous bad reactions to any vaccination and in particular any allergies to eggs, chicken or proteins.
If you happen to have a high temperature on the day of your vaccination it is better to postpone it for a few days until you feel well.
Like all medicines, vaccines can cause side-effects, although not everybody gets them. If you or your child does develop any unusual symptoms, after having had the vaccination, you should contact your doctor or call NHS Direct on 0845 46 47.
Flu vaccines from different manufacturers may differ from one another - please refer to the relevant Patient Information Leaflet for further information on side effects.
If you have any questions or need more information about vaccines and vaccination, please consult your doctor, nurse or pharmacist.