Influenza (flu) is a contagious respiratory illness caused by influenza viruses. Different types and subtypes of the flu virus circulate and cause illness over the course of each flu season, which can last from October through May.
Even though the U.S. Centers for Disease Control and Prevention (CDC) estimates that the flu causes at least 9.2 million illnesses each year, many people choose not to get the vaccine due to misconceptions about its necessity and effectiveness. The CDC dispels those myths here:
Myth: The flu shot is not effective.
Fact: The flu vaccine reduces the risk of flu illness by up to 60 percent when it is well matched to circulating flu viruses. According to the CDC, several factors may result in someone developing flu-like symptoms, even after receiving a flu vaccine:
- They may be exposed to other viruses, such as the rhinovirus (common cold)
- They may have contracted the flu before the vaccine took full effect, two weeks following the shot
- They may be exposed to a different flu virus than the ones the vaccine was designed to protect against
Even considering these factors, vaccination is the optimal choice to reduce the risk of flu illness. In addition, CDC studies show that flu vaccination can reduce the severity of symptoms and flu-related hospitalizations, particularly among children, older adults and people with chronic health conditions.
Myth: The flu shot will cause the flu.
Fact: It is impossible to get sick from the flu shot. The flu shot is given through a needle that contains an inactivated (noninfectious) flu virus. There are no live viruses in the flu shot and you cannot get the flu from an inactivated flu virus.
Myth: Young and healthy people don’t need the flu shot.
Fact: Anyone can get sick with the flu and serious health issues related to the flu can occur at any age. Not only are healthy adults susceptible to the flu, they may be able to infect others a full day before symptoms develop and up to a week after becoming sick.
Myth: You don’t need to keep getting flu shots every year.
Fact: Flu viruses change every year, so new vaccines are developed each year to keep up with the changing viruses. Even if the virus did not change, the body’s immune response from flu vaccination declines over time, so full protection from the flu virus depends on annual vaccination.
Myth: The flu is not that serious.
Fact: The flu is a serious disease, particularly among young children, older adults and people with certain chronic health conditions, such as asthma, heart disease or diabetes. The flu can carry serious complications, hospitalization or death, even among healthy children and adults. Unlike the mild discomforts of a seasonal cold, the flu causes fever, headache, extreme fatigue and body aches. Some people may have vomiting and diarrhea as well, although this is more common in children than adults.
Myth: People should wait to get the shot because it doesn’t last.
Fact: Seasonal flu activity often begins as early as October and November and can continue to occur as late as May. Getting vaccinated before flu activity begins helps protect you once the flu season starts in your community. It takes about two weeks after vaccination to develop immunity. Delaying flu vaccination should be balanced against possible risks of exposure to the flu and vaccine supply shortages.
For best protection against the flu, everyone six months and older should get vaccinated each year. For more prevention tips and flu facts, visit CarilionClinic.org/flu.
This article was reviewed by Beverly Sturgill, director of Infection Prevention and Control, Carilion Clinic Infectious Disease, October 2017.