Say “buh-bye” to the ice cream truck and “hello” to hand sanitizer stations on every corner. Summer may just be on its way out, but the Centers for Disease Control and Prevention (CDC) say we should already be thinking about flu season. But is a flu shot really the best bet for staying healthy this winter? Illustration by Elaine Liu
What’s All the Con-FLU-sion? — The Need-to-Know
But “to vaccinate, or not to vaccinate?” isn’t the only question. (We have it even tougher than Hamlet, huh?) There are also multiple vaccines to choose from! “The shot,” or Trivalent Influenza Vaccine (TIV), might be most familiar, relying on inactivated (dead) flu bugs, which aid in the development of antibodies. So when the true flu hits, those antibodies are already prepared for battle.Even though the height of flu season is winter, the flu can occasionally strike months early. Since the body takes two weeks after vaccination to develop antibodies, the CDC advises anyone six months and older to get the vaccine in early fall each year. And most doctors recommend the vaccine, too—at least for their most “high risk” patients, including pregnant women, the elderly, those with certain medical conditions, and children under the age of four Generalist and subspecialist physicians' knowledge, attitudes, and practices regarding influenza and pneumococcal vaccinations for elderly and other high-risk patients: a nationwide survey. Nichol, K.L., Zimmerman, R. Center for Chronic Disease Outcomes Research, VA Medical Center, Minneapolis, MN. Archives of Internal Medicine 2001 Dec 10-24;161(22):2702-8. .
Scared of needles? Live Attenuated Influenza Vaccine, or LAIV, is the other option, inhaled through the nose. The mist carries live, weakened flu virus, which some suspect is moderately more effective, though research isn’t conclusive Cost-effectiveness of live attenuated influenza vaccine versus inactivated influenza vaccine among children aged 24-59 months in the United States. Luce, B.R., Nichol, K.L., Belshe, R.B., et al. United BioSource Corporation, Bethesda, MD. Vaccine 2008 Jun 2;26(23):2841-8. A prospective, randomized, open-label trial comparing the safety and efficacy of trivalent live attenuated and inactivated influenza vaccines in adults 60 years of age and older. Forrest, B.D., Steele, A.D., Hiemstra, L., et al. Wyeth Vaccines Research, Pearl River, NY. Vaccine 2011 May 9;29(20):3633-9. . But before spraying up, take heed: LAIV isn’t recommended for some patients, including very young children, pregnant women, and the elderly. Certain flu vaccines also aren’t recommended for patients with egg allergies, as the vaccine may include egg protein.
Worth a Shot? — The Answer/Debate
Like most drugs, the flu vaccine has side effects, too. In the case of the shot, most people experience only minor swelling and tenderness at the injection site, but fever, chills, and headaches can also occur— especially among children Side effects of influenza vaccination in healthy older people: a randomised single-blind placebo-controlled trial. Allsup, S.J., Gosney, M., Regan, M., et al. Department of Geriatric Medicine, University of Liverpool, UK. Gerontology 2001 Nov-Dec;47(6):311-4 . Runny nose, headache, and sore throat have also been associated with LAIV. While the short-term side effects (they're usually gone within 24 hours) may be preferable to a week of the flu, vaccinating could be an unnecessary risk if it turns out to be ineffective.
So why get a vaccine that might not work? Unlike many other diseases we’re vaccinated against (think: polio, measles, and mumps— oh my!), the flu vaccine is remixed every year to protect against different strains. The strain selection is based on scientists’ best guess at which three strains are going to be circulating that season. But if a town is struck with a different strain, like Godzilla roaming the streets and tearing up buildings, the vaccine’s antibodies will be rendered powerless. And the predominant strains aren’t positively identified until well after vaccination season. Opponents also argue that flu shots have never actually been proven effective even for the targeted strains— at least not definitively through controlled studies.
One study did reveal, though, that children who were vaccinated and got the flu anyway were more likely to be hospitalized than kids who got sick but hadn’t been vaccinated. Guillain-Barre Syndrome (GBS), a disease that causes paralysis, has also been associated with the flu vaccine, but is extremely rare, occurring in less than 0.02% of cases during the 2009 flu season Preliminary results: surveillance for Guillain-Barré syndrome after receipt of influenza A (H1N1) 2009 monovalent vaccine - United States, 2009-2010. Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report 2010 Jun 4;59(21):657-61. .
Despite arguments against the vaccine, the CDC maintains that flu shots are the best protection against the flu. When in doubt, it’s always best to have a frank conversation with a qualified physician.