Key Facts About Seasonal Flu Vaccine

Why should people get vaccinated against flu?

Influenza (flu) is a potentially serious disease that can lead to hospitalization and sometimes even death. Every flu season is different, and flu can affect people differently, but millions of people get flu every year, hundreds of thousands of people are hospitalized and thousands to tens of thousands of people die from flu-related causes every year. Flu can mean a few days of feeling bad and missing work or it can result in more serious illness. Complications of flu can include bacterial pneumonia, ear infections, sinus infections, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes. An annual seasonal flu vaccine is the best way to help protect against flu. Vaccination has been shown to have many benefits including reducing the risk of flu illnesses, hospitalizations, and even the risk of flu-related death in children. While some people who get a flu vaccine may still get sick, flu vaccination has been shown in several studies to reduce severity of illness.

How do flu vaccines work?

Flu vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against infection with circulating influenza viruses.

Seasonal flu vaccines are designed to protect against the influenza viruses that research indicates will be most common during the upcoming season. All flu vaccines in the United States are “quadrivalent” vaccines, which means they protect against four different flu viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus, and two influenza B viruses.

Who Should Vaccinate?

Everyone 6 months of age and older should get an influenza (flu) vaccine every season with rare exception. CDC’s Advisory Committee on Immunization Practices has made this recommendation since the 2010-2011 influenza season.

Vaccination to prevent flu and its potentially serious complications is particularly important for people who are at higher risk of developing serious flu complications. See People at Higher Risk of Developing Flu-Related Complications for a full list of age and health factors that confer increased risk.

More information is available at Who Needs a Flu Vaccine.