Why I got a flu shot

While visiting Seattle a few months ago, a friend asked me why she should get a flu shot. "I've never gotten the shot. I've only had the flu a few times, and when I did, it wasn't bad. I just don't see the point."

"It's true," I replied. She's a generally healthy twenty-four year old, and, statistically speaking, has very little to fear from the flu. "Chances are getting the flu won't affect you much. But, if you get infected, and then pass it on to someone who's over 75 with weak lungs - that could be really, really awful."

She was silent for a moment.

"Sorry," I said. "I don't mean to be harsh."

"No," she replied, "I see your point. I'll get the shot as soon as I get back home."

We young adults often see little point in sticking ourselves with a needle each year to provide just a 60% reduction in risk from getting the flu. Aside from the momentary discomfort and the cost (mine was about $30; see below for resources to find reduced-price and free immunizations), it doesn't take long to do a web search and find all kinds of alarming pages devoted to exposing the supposed harms of vaccination. It's enough to make an otherwise-healthy person decide to keep their money and take their risks.

For me, though, getting the flu vaccine isn't about myself. I don't hope to disprove or discount the fears that people have about vaccines, but, given the extensive reading I've done and my own personal experience, I've decided that getting the vaccine is worth it. The vaccine tends to be least effective in the people who are at highest risk of developing severe complications from influenza, namely the 65+ crowd. If my getting vaccinated can save them a trip to the hospital or worse, then I see it as my duty to get the vaccine. Zooming out to a population scale, some recent work [1] [2] [3] suggests that school-age children and young adults tend to drive influenza epidemics in their greater communities, so it's likely that wide vaccination coverage for this age group - the one least likely to suffer acute symptoms - will, somewhat counter-intuitively, provide the most effective prevention against severe cases and large epidemics.

That's not to say that the individual benefit for young adults to get vaccinated should be overlooked. While seasonal flu can and does cause severe complications in young adults every year, pandemic flu tends to disproportionately affect school-age children and young adults, often with uncommonly severe symptoms [4] [5]. Vaccination can help in such cases, even if the vaccine is mis-matched to the pandemic strain; Garcia-Garcia et al. note that the general 2009 seasonal flu vaccine likely provided some immunity against the H1N1 pandemic strain, particularly against severe forms [6]. That's important, because we often forget that symptoms can be quite severe; I had no idea that the influenza virus could attack heart cells until I met someone to whom it had happened, and who, in her early twenties, suffered (and thankfully survived) cardiac arrest as a result. 

Flu is serious business. When weighing whether or not to get the vaccine this year, I implore you to think both of yourself and of the others who might be impacted by your decision. The CDC provides lots of great tools for those interested in reading more about the flu, including information about the virus, vaccination, and tracking. 

Take care of yourselves, and each other, this flu season.

Resources for cheap or free flu shots:

References:

[1] Dennis L ChaoM Elizabeth Halloranand Ira M Longini. (2010) School opening dates predict pandemic influenza A(H1N1) outbreaks in the United States. J Infect Dis. 202 (6): 877-80. doi:10.1086/655810

[2] Gog JR, Ballesteros S, Viboud C, Simonsen L, Bjornstad ON, et al. (2014) Spatial Transmission of 2009 Pandemic Influenza in the US. PLoS Comput Biol 10(6): e1003635. doi: 10.1371/journal.pcbi.1003635

[3] Dena Schanzer, Julie Vachon, and Louise Pelletier. Age-specific Differences in Influenza A Epidemic Curves: Do Children Drive the Spread of Influenza Epidemics? Am. J. Epidemiol. (2011) 174 (1): 109-117. doi:10.1093/aje/kwr037

[4] Karageorgopoulos DE, Vouloumanou EK, Korbila IP, Kapaskelis A, Falagas ME (2011) Age Distribution of Cases of 2009 (H1N1) Pandemic Influenza in Comparison with Seasonal Influenza. PLoS ONE 6(7): e21690. doi: 10.1371/journal.pone.0021690 

[5] Lone Simonsen, Matthew J. Clarke, Lawrence B. Schonberger, Nancy H. Arden, Nancy J. Cox, and Keiji Fukuda. Pandemic versus Epidemic Influenza Mortality: A Pattern of Changing Age Distribution. J Infect Dis. (1998) 178 (1): 53-60. doi:10.1086/515616

[6] Garcia-Garcia Lourdes, Valdespino-G√≥mez Jose Luis, Lazcano-Ponce Eduardo, Jimenez-CoronaAida, Higuera-Iglesias Anjarath, Cruz-Hervert Pabloet al. Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City. BMJ 2009; 339:b3928