Do flu vaccines make you sicker?

In another video, RFK Jr. claims that flu shots weaken the immune system, making people more likely to get non-flu illnesses, including COVID.

RFK Jr. claims that the Pentagon proved flu shots make people more likely to get the flu or COVID, but the study he refers to actually says the opposite. The study’s conclusion clearly states that getting a flu shot did not make people more likely to catch other viruses. It also shows that the flu vaccine provides strong protection against many illnesses, including different types of flu, parainfluenza, RSV, and other non-flu viruses. The Department of Defense still requires flu vaccination because it helps keep service members healthy and prevent illness.

He also points to a claim that the flu vaccine causes 4.4 times more illness, based on a study of only 115 children. But that same study also looked at about 6,000 adults and found that vaccinated adults had fewer non-flu respiratory illnesses, not more. Anti-vaccine sources sometimes use only the parts of studies that support their message, while ignoring the rest. This is why scientists look at full datasets, not one small number taken out of context.

RFK Jr. further claims that the flu shot “enhances” coronavirus infections. But the study cited for this claim shows that the flu vaccine does not make people more likely to get COVID or get sicker from it. Instead, vaccines help protect against serious illness from respiratory viruses.