Does the adult flu vaccine have any side effects or harms?

It is generally safe for adults to receive influenza vaccines, but mild adverse reactions such as local pain, fever or fatigue may occur. These are normal immune responses and serious adverse reactions rarely occur. To ensure safety, it is recommended to receive the vaccine at a regular medical institution and assess the risk of vaccination based on personal health status.

1). Mild side effects

Common mild reactions include pain, redness, swelling or nodules at the injection site. This is a normal response of the human immune system to the vaccine components. It does not require special treatment and usually resolves on its own within 1-3 days. Some adults may feel a slight fever, fatigue or muscle aches, and this systemic reaction is also short-lived. For these reactions, the discomfort can be relieved by proper rest, local cold compresses or drinking plenty of water.

2) Risk of allergic reaction

A very small number of people may be allergic to the ingredients in the flu vaccine, especially those who are allergic to protein, because most flu vaccines currently involve chicken embryo technology in the production process. If you experience a rash, difficulty breathing, or sore throat within a short period of time after vaccination, you should seek medical attention immediately. Before vaccination, be sure to tell your doctor about your personal allergy history and follow the doctor's advice to choose the type of vaccine that suits you, such as the genetically recombinant vaccine, which does not contain protein.

3). Other rare adverse reactions

Rarely, adults may experience adverse reactions to the nervous system after receiving the flu vaccine, such as Guillain-Barré syndrome (GBS), a rare but temporary immune response. People with a history of related illnesses need to consult a doctor before vaccination and observe their physical condition after vaccination. If persistent discomfort occurs, seek medical attention immediately.

The risk of influenza vaccination is much lower than the risk of contracting influenza and its serious complications, and it is especially protective for the elderly, those with chronic diseases or weakened immune systems. It is recommended to communicate with a doctor about your health status before vaccination, receive the vaccine under the supervision of a medical institution, and observe the reaction after vaccination. In most cases, the adverse reactions to the vaccine are mild and controllable, and the overall benefits of vaccination outweigh the risks.