“Flu season” has become such a commonplace turn of phrase that it’s easy to overlook just how big a threat the flu can pose.

Estimates from the U.S. Centers for Disease Control and Prevention suggest that as many as 41 million illnesses and 52,000 deaths each year can be attributed to the flu.

There’s no denying that the flu can be a formidable foe, even for those who recover from it within a few days of becoming ill. Flu vaccines can make cases of the flu more manageable, making now a great time to answer some common questions that arise every flu season.

Why are flu vaccinations important? The CDC notes that annual flu vaccinations help to reduce the risk of getting the flu. But it’s also worth noting that a flu shot helps to prevent more serious complications for those people that do get it. Such complications can include ear infections, sinus infections, bacterial pneumonia, and the worsening of chronic conditions like asthma and diabetes.

How do flu vaccines work? Researchers work year-round to get an idea of which influenza viruses are likely to be most common in a given flu season. This is why flu vaccines change from year to year. Regardless of those changes, the CDC notes that all flu vaccines work in the same way, with each causing the development of antibodies in the body within a couple of weeks of vaccination. These antibodies protect against the flu virus.

Flu viruses are constantly changing, so a vaccination that might have been effective one year will not necessarily provide significant protection in the following year. In addition, the protection provided by the flu vaccine wanes over time, so people won’t necessarily be well fortified against the flu if they aren’t vaccinated each year.

Do flu vaccines take individuals into account? The CDC notes that, during the 2022-23 flu season, three flu vaccines are preferentially recommended for people ages 65 and older. That recommendation was based on research suggesting the three vaccines are more effective for people in this age group than the standard dose flu vaccine. For the 2022-23 flu season, the CDC has no preferential recommendation for people under 65.

Should everyone receive a flu shot? Though there are rare exceptions, the CDC urges all individuals age six months and older to get a flu shot every year. Vaccination can be especially important for people considered to be at elevated risk of serious complications should they develop the flu. This includes individuals over 65, people with chronic health conditions and children younger than two-years-old, among others. A more complete list of people who could be at high risk of flu complications is available at cdc.gov/flu/highrisk/index.htm. Am I protected immediately after receiving a flu shot? The flu shot does not provide immediate protection. The CDC notes that it takes roughly two weeks for antibodies to develop and provide protection against the flu virus. This is one reason why it’s wise to get a flu shot before flu season begins.

Flu vaccines are a highly effective mode of protection against influenza viruses. More information is available at www.cdc.gov.