The Truth About Flu Vaccine

According to the CT Department of Public Health, the flu is now widespread in our state. With all the news stories out there about people scrambling to get flu shots, there is a lot of misinformation going around regarding the safety of the flu vaccine.

At Ledge Light Health District, we thought this was the perfect time to start up a new blog and use our first post to set the record straight about flu vaccines.

Lately, we have been seeing a lot of comments on news stories about the latest flu outbreak that say something like this: “Every time I’ve gotten a flu shot, I’ve gotten the flu. It must be the shot that gave me the flu!”

The flu shot does not give you the flu. A flu shot contains an inactivated (aka dead) flu virus, so it cannot infect your body with the flu. According to the CDC, there are several reasons why someone could experience flu-like symptoms after getting a flu shot:

1. “People may be exposed to an influenza virus shortly before getting vaccinated or during the two-week period that it takes the body to gain protection after getting vaccinated.” That’s right; it takes two weeks for the flu vaccine to start protecting your body against the flu. As much as we’d love to be able to get a flu shot gives us instant protection from the flu, that’s just not the way it works.

2. “People may become ill from other (non-flu) viruses that circulate during the flu season, which can also cause flu-like symptoms (such as rhinovirus).” People often assume they have the flu when they are experiencing symptoms like fever, chills, vomiting, or sore throat during flu season. The only way to find out for sure if you have the flu is to see your doctor.

3. “A person may be exposed to an influenza virus that is not included in the seasonal flu vaccine. There are many different influenza viruses that circulate every year. The flu shot protects against the 3 viruses that research suggests will be most common.” This year, the 3 strains included in the vaccine (H1N1, H3N2, Influenza B) are a good match for the most common strains that are going around.

4. “Protection provided by influenza vaccination can vary widely, based in part on health and age of the person getting vaccinated. In general, the flu vaccine works best among young healthy adults and older children. Some older people and people with certain chronic illnesses may develop less immunity after vaccination.” This season’s flu vaccine is reported to be about 60% effective against the flu, which means there is a chance you could still get the flu after getting a shot, but your symptoms would be greatly reduced.

So, while it is possible you could get sick sometime after getting a flu shot, it is not possible to get the flu from a flu shot. The most common side effect of a flu shot is soreness at the injection site. The CDC says rare symptoms such as fever, muscle pain, and feelings of discomfort or weakness can occur soon after getting a flu shot and last 1-2 days.

For more information about the seasonal flu vaccine, visit the CDC website.