Fall is the time of year for getting our flu shots. I’ve had mine every year since I started medical school in 1985. I hope that you will all plan to get your flu shots this year.
Why do you need a flu shot every year?
There are 2 main type of flu viruses, influenza A and B viruses. Within those two types, there can be hundreds of different strains, which are constantly changing. A different strain of flu is responsible for causing the flu from one year to the next.
Also, immunity wanes over time.
How do they decide which strain to use to make the flu shot?
In the US, all flu shots are quadrivalent, which means they protect against four different flu viruses. Each year, scientists use research to predict which strains will be most common during the upcoming season. The shots are made to fight those strains.
Why are people 65 and older recommended to have a different type of flu shot?
People 65 and older are at higher risk of developing serious complications from the flu compared to younger adults. In recent years, between 70- 85% of seasonal flu-related deaths and between 50-70% of flu-related hospitalizations have happened in people 65 and older. This is at least partially related to changes in the immune system with age.
Specialized flu shots have been developed to help increase the immune response to the shot by using higher doses or special immune boosters. These shots are recommended for people 65 and older. For more information use this link: Flu & People 65 Years and Older | CDC
Who should get the flu shot?
Everyone 6 months and older in the US should get a flu shot every year with rare exception. To see more information about who should and who should NOT get a flu shot, use this link: Who Needs a Flu Vaccine | CDC
Can the flu shot give you the flu?
No. Flu shots given with a needle are made with either inactivated (killed) viruses, or with only a single protein from the flu virus. The nasal spray flu “shot” contains live viruses that have been weakened so that they will not cause illness.
Some people do have about 12-24 hours of feeling achy or even having a slight fever after a flu shot. This is due to the immune response to the vaccine, not a flu infection. These brief symptoms are nothing compared to having a true influenza infection.
Why do some people still get sick with flu symptoms even though they got a flu shot?
There are a few reasons why someone might still get flu symptoms despite having had the flu shot:
- There are lots of other viruses that can cause a flu-like illness that spreads in the community during the typical flu season, including multiple cold viruses and even COVID-19. Flu shots only protect against influenza, not other respiratory illnesses.
- Some people get exposed to the flu virus shortly before getting the flu shot, or in the 2 weeks after the shot, when your immune system is still building its response to the shot. This exposure can result in an infection before protection from the shot takes effect.
- Flu shots can vary in how well they work from year to year. Some years, the flu viruses that are spread in the community do not match those in the vaccine because the prediction was not accurate. Luckily, with the ability to protect against 4 different strains, the flu shots are usually effective. If it does happen, flu vaccination can still reduce the severity of illness, even though it may not prevent the infection entirely. If you have any questions about the flu shot, please log into your account and send us your question. We are here to help.
If you have any questions about flu shots, please log into your account and send us your question. We are here to help.
Dr. Anita Bennett MD – Health Tip Content Editor