Flu season means flu vaccine time. Th widely available influenza vaccine is one of the most effective ways to stop the spread of the contagious viral illness. The flu virus changes slightly from year to year, which is why a new vaccine is needed each season, but the vaccine provides long-term protection against each season’s specific strain of the disease.
The flu vaccine works in two primary ways. First, it prompts the immune system to produce antibodies that fight off a specific strain of influenza virus, making it easier for the body to rid itself of an infection before it can cause illness. Second, it reduces the level of flu virus in the population, so people fewer are exposed to the virus in the first place. This means the vaccine is effective even for the small number of people who do not produce sufficient antibodies in response to the vaccine, or for whom vaccination is unsafe.
In some cases people are reluctant to get vaccinated because of erroneous beliefs about the vaccine. While the vaccine does contain flu virus, it is in an inactive form, enough to trigger an immune response, but not enough to actually sicken most people. The vaccine can cause side effects in some patients, but many fears—of neurological problems, of heart disease, of Alzheimer’s—are exaggerated, or often the opposite of the case, in that flu vaccine reduces these risks. Conversely, people often liken "flu" to a bad cold, even though flu killed thousands of people per year.
There are people for whom flu vaccine is not recommended. People who have had severe allergic reactions in the past are poor candidates for vaccination. None of the types of vaccines are approved for children under six months. People who are not feeling well should get better before being vaccinated. Other people need to take precautions before vaccination. It may not be possible for people with egg allergies to receive the vaccine, and they should discuss the best course of action with their healthcare professionals. Similarly, people with Guillain-Barré syndrome are prone to complications and should talk to a doctor. Vaccination is recommended for everyone else, particularly people under four or over 50 and their caregivers, children or teenagers on aspirin therapy, people with suppressed immune systems, people with certain chronic conditions such as diabetes, health care workers, and anyone else at high risk of flu complications.