Principally speaking, if you are vaccinated, you are less likely to get the flu. This means, a flu shot does not guarantee that you won’t get the flu, but it provides you with partial immunity. According to Centers for Disease Control and Prevention (CDC), the flu vaccine reduces the odds of getting the flu by about 60% subject to yearly variation and different age groups.
So why is it that the flu vaccine won’t work all the time? Let us dig a little deeper and learn about the various reasons:
- Match of Vaccine with Viral Strains: Viruses change over time. That means the protection provided by a flu vaccine in one year cannot be carried over into the next year. For a flu vaccine to protect a person, it is largely dependent on the “match” between the vaccine and the dominant flu strains. So a vaccine fails to work if there are more dominant viruses present that were not covered in the preparation of the vaccine.
- Other illnesses: Some people fall ill from other respiratory viruses besides flu and also spread illness during the flu season. A common example is a rhinovirus, which is associated with cold and has similar symptoms. A flu vaccine only provides protection against influenza, not other illnesses including a cold virus.
- Age and General Health: The flu vaccine is most effective in healthy adults. After middle age, the immunity becomes weaker and so older people are always advised to take flu shots. If nothing, it at least makes the symptoms milder and not life-threatening.
- Body’s Response Time: Even if you take a flu shot, you may still catch the flu if your body gets exposed to the virus in sooner than two weeks, that is because the body takes two weeks to build up enough antibodies to provide immunity against viruses. Also, in a case where you have taken the vaccination shot a lot earlier than the commencing of flu period, the effectiveness of the vaccine wears out.
- Suppressed Immune Systems: In many cases, a flu vaccine fails to work because the body cannot detect the ‘inactivated virus’ used to make the vaccine. This inactivated flu virus is responsible for finding a chemical match in your body so that it can start the production of antibodies.
Even though a flu vaccine may not be a sure bet, there is no harm in getting vaccinated. After all, it is a safer choice than risking serious illness that may even become threatening.