- What is flu?
- What are the symptoms of flu?
- Who is at greatest risk from flu?
- Why should I be vaccinated?
- Where can I get vaccinated?
- When can I get vaccinated?
- How often do I need to be vaccinated?
- Am I eligible for a free vaccination?
- Will a flu vaccination give me flu?
- How does a flu vaccination work?
- How are flu vaccines produced?
How does a flu vaccination work?
Flu vaccines work by stimulating our immune system to produce antibodies that fight flu – without actually infecting us1. (Antibodies are proteins that recognise and fight off germs, such as the flu virus.)
Following a flu vaccination, if you are exposed to the same influenza strains, your immune system recognises it, and produces the antibodies needed to fight it1. It takes about 10 to 14 days for your immunity to fully develop after having the flu vaccination1.
To understand how the flu vaccine works, it’s important to also understand the different types of flu viruses it needs to fight.
Types of flu virus which infect humans
- Type A: This usually causes more severe flu symptoms and is also most likely to mutate into a new strain that people are not resistant to1
- Type B: This generally causes less severe symptoms and mainly affects young children1
- Type C: This causes mild symptoms, which are similar to having a cold1
Most seasonal flu vaccines are made of three or four different types of inactivated flu virus (usually two A types and one or two B types)1. This is because these are the most common types of flu that people are likely to catch during a flu season2.
A new flu vaccine is developed and is provided each to year to protect against the specific flu strains that are circulating that year. While it can’t offer 100% protection against every single strain of flu3, it certainly reduces your chances of catching it, and also reduces how serious the symptoms may be if you do.
Vaccination is the most effective way to avoid developing the flu4.
You can get your free NHS flu vaccination* at your GP surgery or in a pharmacy, while most pharmacies in the UK also offer private jabs.
*Free NHS jabs are available only to those who fall within the current risk categories.
- NHS Choices. How the flu vaccine works. July 2016. Available online: http://www.nhs.uk/conditions/vaccinations/pages/how-flu-vaccine-works.aspx (accessed July 2018)
- World Health Organization. Recommended composition of influenza virus vaccines for use in the 2018-2019 northern hemisphere influenza season. Available online: http://www.who.int/influenza/vaccines/virus/recommendations/2018_19_north/en/
(accessed July 2018)
- NHS Choices. The flu vaccine. July 2016. Available online:
https://www.nhs.uk/conditions/vaccinations/flu-influenza-vaccine/ (accessed July 2018)
- World Health Organization. Influenza (Seasonal) Fact Sheet, January 2018. Available online: http://www.who.int/en/news-room/fact-sheets/detail/influenza-(seasonal) (accessed July 2018)