Does the Flu Shot Make You Sick?

can the flu shot make you sick

Although allergic reactions to the flu vaccine are uncommon, some people can develop an allergic reaction to the vaccine. Some people may experience breathing difficulties, hoarseness, wheezing, hives, paleness, or dizziness after receiving the shot. Some people even experience allergic reactions just a few hours after getting the flu vaccine. People who are extremely allergic to egg protein should avoid the vaccine to prevent this type of severe reaction.

While the flu vaccine will give you immunity to influenza, it can also cause a low-grade fever. While this is common, it does not necessarily mean you’ll catch the flu. A high-grade fever, if present, may be due to a different illness. It may also be a sign of an underlying cold or respiratory syncytial virus. In addition, delayed vaccination may cause an incubated influenza virus, which is unrelated to the flu vaccine.

A vaccine contains weakened live influenza virus, but it is inactive. Inactivated influenza viruses do not infect cells, so they cannot make you sick. However, when immune cells detect a virus-like particle, they fire off chemical alarms and try to make your body unlivable to pathogens. This reaction may cause fever or a lump to appear near the injection site. While the flu shot does not make you sick, it should be considered a preventative measure for pregnant women and those with weakened immune systems.

The flu vaccine can protect you from the flu and many other common respiratory infections, although it is not always enough to prevent infection. Vaccination should not be delayed or skipped if you have a preexisting medical condition. Besides being safer, flu vaccines have the same protective effects as the flu itself. In addition, a flu vaccine does not weaken your immune system, it simply activates an immune response that prepares your body for an active virus.