What are the benefits of flu vaccination?

Note: “Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2021-2022 Influenza Season” has been published. More information on the upcoming 2021-2022 season is also available.

There are many reasons to get an influenza (flu) vaccine each year. Flu vaccination is the best way to protect yourself and your loved ones against flu and its potentially serious complications.

Below is a summary of the benefits of flu vaccination and selected scientific studies that support these benefits.

    • Flu vaccination prevents millions of illnesses and flu-related doctor’s visits each year. For example, during  2019-2020 flu vaccination prevented an estimated 7.5 million influenza illnesses, 3.7 million influenza-associated medical visits, 105,000 influenza-associated hospitalizations, and 6,300 influenza-associated deaths.
    • During seasons when flu vaccine viruses are similar to circulating flu viruses, flu vaccine has been shown to reduce the risk of having to go to the doctor with flu by 40 percent to 60 percent.
  • Flu vaccination has been shown in several studies to reduce severity of illness in people who get vaccinated but still get sick.
    • A 2021 studyexternal icon showed that among adults, flu vaccination was associated with a 26% lower risk of ICU admission and a 31% lower risk of death from flu compared to those who were unvaccinated.
    • A 2018 studyexternal icon showed that among adults hospitalized with flu, vaccinated patients were 59 percent less likely to be admitted to the ICU than those who had not been vaccinated. Among adults in the ICU with flu, vaccinated patients on average spent 4 fewer days in the hospital than those who were not vaccinated.
  • Flu vaccination can reduce the risk of flu-associated hospitalization.
    • Flu vaccination prevents tens of thousands of hospitalizations each year. For example, during 2019-2020 flu vaccination prevented an estimated 105,000 flu-related hospitalizations.
    • A 2014 studyexternal icon showed that flu vaccination reduced children’s risk of flu-related pediatric intensive care unit (PICU) admission by 74 percent during flu seasons from 2010-2012. A 2017 study found that during 2009-2016, flu vaccines reduced the risk of flu-associated hospitalization among older adults by about 40 percent on average.
    • A 2018 study showed that from 2012 to 2015, flu vaccination among adults reduced the risk of being admitted to an intensive care unit (ICU) with flu by 82 percent.
  • Flu vaccination is an important preventive tool for people with certain chronic health conditions.
    • Flu vaccination has been associated with lower rates of some cardiac eventsexternal icon among people with heart disease, especially among those who have had a cardiac event in the past year.
    • Flu vaccination can reduce the risk of a flu-related worsening of chronic lung disease (for example, chronic obstructive pulmonary disease (COPDexternal icon) requiring hospitalization.
    • Among people with diabetesexternal icon and chronic lung diseaseexternal iconflu vaccination also has been shown in separate studies to be associated with reduced hospitalizations from a worsening of their chronic condition.
  • Flu vaccination helps protect pregnant people during and after pregnancy.
    • Vaccination reduces the risk of flu-associated acute respiratory infection in pregnant people by about one-half.
    • A 2018 studyexternal icon showed that getting a flu shot reduced a pregnant person’s risk of being hospitalized with flu by an average of 40 percent from 2010-2016.
    • A number of studies have shown that in addition to helping to protect pregnant people from flu, a flu vaccine given during pregnancy helps protect the baby from flu for several months after birth, when he or she is too young to be vaccinated.
  • Flu vaccine can be lifesaving in children.
    • A 2017 study was the first of its kind to show that flu vaccination can significantly reduce a child’s risk of dying from flu.
  • Getting vaccinated yourself may also protect people around you, including those who are more vulnerable to serious flu illness, like babies and young children, older people, and people with certain chronic health conditions.

Despite the many benefits offered by flu vaccination, only about half of Americans get an annual flu vaccine and flu continues to cause millions of illnesses, hundreds of thousands of hospitalizations and tens of thousands of deaths. Many more people could be protected from flu if more people got vaccinated.

*References for the studies listed above can be found at Publications on Influenza Vaccine Benefits. Also, see the A Strong Defense Against Flu: Get Vaccinatedpdf icon! fact sheet.