How Long Does A Flu Jab Last?
How long does the flu vaccination last?
The flu virus is constantly evolving, therefore the flu jab you receive one year will not be effective against the flu present the following year. It will only be effective for the year it was designed for.
In order to understand this answer, it’s important to look into how the flu vaccine works. At the beginning of each year, the WHO (World Health Organisation) gathers data to assess the strains of the virus in circulation before making a prediction about which ones will likely be present during the upcoming year. Based off this suggestion, the flu vaccine is then formulated to protect against three or four different strains of the flu virus.
The flu vaccine is therefore different every year, and some years it has a greater success rate than others.
When should I get the flu jab?
Using the recommendations from the WHO, the vaccine goes into production in March and usually becomes available in the UK from September. Every year, the timing of the onset and peak of the flu season changes making it hard to pinpoint the exact moment when it’s best to have the flu jab. According to the NHS, people should aim to have the flu vaccine during October or November, although it’s not a problem if you get the jab later in winter.
How effective are flu jabs?
The effectiveness of the flu vaccine changes from year to year because every year the strains are different. According to research by Public Heath England, the flu vaccine prevented 52% of flu cases in 2015-16, 40% of flu cases in 2016-17, 15% of flu cases in 2017-18 and 44% of flu cases in 2018-19.
Whilst it’s still possible to catch the flu even when you’ve had the vaccine, the chances of you developing severe symptoms is greatly reduced if you’ve had the jab. The CDC (Centers for Disease Control and Prevention) conducted a number of studies in the US on the effectiveness of the flu jab and discovered that they reduce the risk of flu illness by 40% - 60%. Serious complications from the flu include:
- Pneumonia – an infection which causes the lungs to fill with fluid.
- Bronchitis – an infection of the main airway of lung which leads to coughing and inflammation.
- Asthma flareups – those with the chronic condition will find it more difficult to manage their symptoms if they have the flu.
- Heart problems – there is an increased risk of heart attack if you have the flu.
- Ear infections – the virus can spread and cause congestion.
What type of flu jab will I be offered?
Your GP will determine the most effective type of vaccine for you as there are several types on offer depending on your age:
- Children aged 2-17 – offered a live quadrivalent (triggers immune response against four different antigens) nasal spray vaccine.
- Adults aged 18-64 – offered an inactive quadrivalent injected vaccine.
- Adults aged 65 and over – offered either an adjuvanted trivalent (helps trigger a stronger immune response against three different antigens) injected vaccine or a cell-grown quadrivalent injected vaccine.
Whilst nasal spray vaccines are generally offered to children, if your child is in a high risk category then they may be offered the flu vaccine in the form of an injection instead.
If I had the flu jab last year, do I need to get another one again?
Yes. If you received the flu jab last year, you will not be protected against the flu virus in circulation for the upcoming year. Receiving an annual flu vaccine is the most effective way of protecting you and others around you from the flu through herd immunity.
Herd immunity works when enough people are vaccinated making it harder for the virus to spread throughout the community. For example, if one infected person enters a room of six people who have all been vaccinated, the chances of any them catching the flu are greatly reduced meaning the virus has nowhere to go.