For many vaccines, booster shots are important to maintaining prevention against diseases. This is true for diseases such as hepatitis A and B, yellow fever, and HPV.
But, what about influenza?
During the flu season, people are wary of the dangerous virus. It’s an exciting thought that a second-dose of the flu shot may increase our immunity to the flu as other booster shots do for other diseases. With even more protection, some might think risks of the flu could disappear.
This may be the case for some individuals, but the real question is: Do booster shots serve a purpose for the whole population?
The answer, in short, is no.
The CDC recommends that all children and adults receive the flu vaccine as it is available each year. Although, they only recommend the necessity of two doses for specific cases.
According to the Mayo Clinic, one of these specific cases is a child. A child should consider getting two doses if they are under age nine and getting the vaccine for the first time. Due to the dose schedule, they should receive the first dose before January for this to be most effective.
Another group that may benefit from receiving a second dosage are organ transplant recipients. Their compromised immune systems can use the extra help to fight the bacteria. A study conducted in 2012 proved that two doses of the influenza vaccine could have positive effects in protecting these individuals against influenza.
This has not been proven yet to be the case for other instances or diseases that compromise an individual’s immunity.
Lastly, an instance where a second dosage would be effective would be in cases of a pandemic flu. A pandemic flu occurs when there is a worldwide epidemic in which our immune systems are not equipped to fight against a new flu strain. This instance is rare and the last pandemic flu in the United States occurred in 1918.
If a second dose is deemed necessary, the second dose will be administered at least four weeks after the first dose. As mentioned before, that means that an individual seeking a second dose, should get the first before January. The CDC recommends that individuals receive the vaccine as soon as it becomes available.
If you do receive a second dose of the flu shot and aren’t in the populations listed above, nothing terrible will happen. You may increase your risk of experiencing common side effects of the vaccine in general (fever, pain at the injection site), but it is overall harmless.
In the end, while two doses of the flu shot may be helpful to some people in further protecting themselves, it doesn’t serve as a necessity for everyone.
Do you have any other questions about the flu or its vaccine? Are you still need of the flu shot for this year? Passport Health can help. Give us a call at or book an appointment online to receive your flu shot.
Written for Passport Health by Kaitlyn Luckow. Kaitlyn is a freelance writer, photographer and English teacher in Milwaukee. She has a passion for capturing and writing other people’s stories. You can find her at sayhellostory.com.