According to the Centers for Disease Control and Prevention (CDC), the seasonal flu accounts for over 200,000 hospitalizations and 36,000 deaths each year. Getting vaccinated against the flu each year is the single best thing people can do to reduce their risk of getting the flu. Vaccination also offers other benefits, including decreasing the risk of influenza-related complications and helping to protect other people who may not respond to the vaccine on their own.
Decreased Risk of Influenza
According to the CDC, the seasonal flu vaccine can reduce the risk of getting influenza by 70 percent to 90 percent in healthy adults. Flu Mist, the live attenuated intranasal vaccine, may offer even more robust immunity than the more popular inactivated injectible vaccines. However, a direct comparison isn't possible because Flu Mist is contraindicated in many of the people who are considered at high risk for influenza, such as infants, elderly people and people with other medical problems.
Decreased Risk of Complications
Seasonal flu vaccine doesn't prevent all cases of influenza, for two reasons. According to a 2008 article in the journal Vaccine, the influenza virus is constantly mutating. Therefore, the strain that a person is infected with may not be a perfect match with the strain in the vaccine. Also, some people don't respond to the vaccine or respond incompletely. However, in both cases, seasonal flu vaccination still reduces the risk of severe illness and complications that require hospitalization through a process the CDC calls "cross-match." Seasonal flu vaccine triggers the body to make some antibodies--which, even if they aren't completely effective at preventing the disease--decrease its severity and helps people recover faster.
Herd Effect
The people at greatest risk for severe illness due to influenza are also those who are most likely to have a weak or absent response to the vaccine. However, vaccination in other healthy people helps protect these people, too. This is called the "herd effect," which works because fewer people infected with influenza also means fewer people to spread the disease. Accordingly, the CDC's Advisory Committee on Immunization Practices specifically recommends that people who live with or care for those at high risk for serious seasonal flu-related complications get vaccinated each year, even though they themselves are not at high risk.
References
- Centers for Disease Control and Prevention
- Vaccine; The Biology of Influenza Viruses; N.M. Bouvier, P. Palese; September 12 2008
- Centers for Disease Control and Prevention
