The flu tends to be the leaky basement pipe of disease: It’s easy enough to avoid doing something about it, right up until the point it completely bursts and ruins your month. But the flu is much more deadly than a flooded basement. Even at its weakest in recent years, the virus killed at least 12,000 Americans during the 2011-2012 season. And while this current flu season isn’t the world-shattering pandemic seen in 1918-1919, when a particularly bad strain infected around a third of the world’s population and killed 20 million to 50 million people, it’s gearing up to be the one of the worst in years. California hospitals have had to set up emergency tents in their parking lots to accommodate the deluge of flu victims. All of which is to say: For the love of god, no matter what your friends or family tell you or the rumors you’ve heard, just get the damn flu shot. It’s not too late.
That’s the TLDR version. The longer version is that flu vaccination is just about the only way we have available to prevent the flu (antivirals can help once you’ve got it, but they’re not wonder drugs). Not vitamin C, not antibiotics, not whatever supplement is trending—the vaccine is the best way to prevent the flu.
That doesn’t mean it’s a perfect option, and especially not this flu season. There are two broad types of the influenza virus (four in total) that make people sick, A and B. Type A flu viruses are typically more virulent. Before each upcoming flu season, scientists at the World Health Organization play a guessing game, trying to predict which strains of A and B flu viruses will most circulate in the environment. The seasonal vaccine confers protection against three to four of these strains. But sometimes the guesses are off-base, usually because the virus mutates quicker than expected. Some strains are particularly quick to mutate, making them harder to protect against.
The main A virus in vogue this winter, H3N2, is one such flu strain. A 2016 review found vaccines against H3N2 over the past decade have only been around 33 percent effective. This season, there’s been whisperings that the shot is even more mismatched. A study released last October, for instance, reported the current vaccine may actually only be 10 percent effective against H3N2, based on early data from Australia, where the flu season starts in the summer. The way our flu vaccines are often produced, via flu viruses that are incubated in eggs, might contribute to this lowered protection.
The exact same vaccine used in Australia is used in the U.S. And if the flu numbers in the U.S. turn out to be anywhere near as drastic as they were down under, then, yikes. Over 200,000 Australians were reported to have flu by that October—up from around 50,000 in typical years. The number of deaths and hospitalizations caused by flu were also predictably higher than usual.
In the U.S., the Centers for Disease Control and Prevention (CDC) has estimated that widespread flu activity was visible across all 50 states by the end of December, a trend not seen once in the 13-year history of the current flu surveillance system, according to Dan Jernigan, director of the Influenza Division in the National Center for Immunization and Respiratory Diseases at the CDC. Jernigan and his colleagues believe this current flu season may eventually match the toll of disease and death seen during the 2012-2013 and 2015-16 seasons, which also prominently featured H3N2. The 2012-2013 season, for context, resulted in over 700,000 hospitalizations and around 56,000 deaths caused by flu.
Already, there have been many tragic flu deaths seen stateside. A 21-year-old male bodybuilder; a 40-year-old mother who ran regularly; a 10-year-old boy who loved hockey. These deaths are noteworthy because of how unusual they are. Typically, it’s the very young, the elderly, and the otherwise immunocompromised who will bear the most serious blows from the flu.
The good news, if any, is that we might be passing through the worst of the season. But there are still 13 weeks left before the season is expected to end. And while 10 percent effectiveness isn’t a great number to hang your hat on, it’s better than nothing at all. The vaccine also provides (better) protection against the other A and B strains around this year, which will make up 20 percent of cases this season.
The seasonal flu vaccine, even when not completely preventative, still tends to weaken the severity of a bout of flu, including H3N2. And it saves lives: A 2015 study by the CDC found that seasonal shots had prevented at least 40,000 deaths from 2005 to 2014, including nearly 10,000 deaths during the 2012-2013 season, when the vaccine was similarly lackluster against the seasonal H3N2 strain. The study only looked at deaths prevented through a direct flu shot, but the effect would probably be even more dramatic when you consider herd immunity. Put simply, every person whose shot protects them from getting the flu is one less person who can spread it to someone else who didn’t get protected.
So yeah, needles suck. Your arm might be sore for the rest of the day. And sometimes you or your friends (wrongly) swear that the shot gave you the flu. But Christ almighty, just get the damn shot already.