It’s hard to miss. As the first leaves begin to blush and kids settle into school time routines, area pharmacies, doctor offices and other community venues practically beg you to stop, roll up your sleeve and be vaccinated.
Despite the vaccine’s impressive safety record, stubborn myths and honest questions persist. Can you contract the flu from the shot? Is annual vaccination overkill, especially if you’re young, fit and generally healthy?
If you’ve ever had reservations, you’ll want to take a minute to scan this quick interview with infectious disease expert and flu guru Dr. John Treanor.
Scripts: Many people know a friend who got terribly sick a day or two after being immunized. I thought you couldn’t contract flu from the shot?
Treanor: That’s right; the vaccine really can’t make you sick because it doesn’t contain living virus. Each dose holds just enough inactivated (“dead”) virus, rousing your immune system with a dress rehearsal of sorts. Essentially, you practice turning out the antibodies you’ll need in the event of a real infection down the road. That’s why you might feel a low-grade fever, or a little soreness and swelling at the injection site. But it’s certainly not to be confused with a full-blown case of flu!
A few things make this myth particularly sticky. One is that, when we give the flu shot, there tend to be a host of other respiratory germs circulating. Rhinovirus, which causes the common cold, might easily be confused for a mild case of the flu — and mis-attributed as a flu vaccine side-effect.
Another confounding factor is the lag time between the shot going into your arm and your body being fully protected. It can take a full two weeks to confer complete immunity, you may still be susceptible to flu in that brief time window after vaccination.
Finally, flu evolves. Scientists do the best job they can forecasting which strains of virus will be the big players in a coming season, but it’s impossible to always guess perfectly. Some years, predictions play out pretty accurately. Other years, they don’t match up as well.
Scripts: That makes sense. But, if I got a shot last year, do I really need a new one? Has the composition of the vaccine changed much since last season? And if not, do I really need another one?
Treanor: One of the strains (the H1N1 virus) is carried over from last year’s vaccine, but the other two (trivalent vaccines, as the name suggests, pack protection against three strains apiece) are in fact new.
In any event, it’s too complicated to adjust your vaccination habits based on whether the components change. What’s more, it seems that virus-fighting antibodies wane over time, so we advocate yearly vaccination.
Scripts: If protection theoretically ebbs, when’s the best time to get a shot? It seems they’re available earlier and earlier, by more and more retailers in my neighborhood.
Treanor: This is a yearly controversy, especially since flu season tends to peak late in the winter in Rochester. But the general recommendation is to start immunizing as soon as vaccine becomes available in communities, because the precise onset of the season is hard to plan for. You certainly don’t want to waste the opportunity to get vaccinated by waiting around too long. (Remember, it can take weeks for immunity to mount to truly protective levels.)
This said, within reason, it’s also never too late to get vaccinated. Flu seasons hardly seem as predictable as they used to be. The H1N1 pandemic, which threw us for a loop a few years back, bore down hard in the spring! You just never know.
Scripts: True. One final question – what’s all the hubbub about a new, quadrivalent vaccine? Is it really better – and where can I find one?
Treanor: There’s a good chance the seasonal flu vaccine will be fundamentally different in the near future, thanks to the FDA’s approval of a four-strain (quadrivalent) vaccine this past spring. Put simply, manufacturers have developed a vaccine that folds in protection against yet one more flu strain (two flu A, two flu B), instead of just three (typically, shots inoculate people against two As and just one B).
Don’t bother with a wild goose chase this fall; they probably won’t be very available this season. But stay tuned. They could be more standard in late 2013.
John Treanor, M.D., professor of Medicine, Microbiology and Immunology, serves as the chief of the Infectious Diseases Division of the Department of Medicine at URMC.
A widely recognized expert in influenza and vaccine research, he’s best known for helping to lead the nation’s efforts to find a vaccine to protect against bird flu. Largely as a result of his work (he led the pivotal studies that showed that large doses of the vaccine are safe and effective), in 2007 the U.S. Food and Drug Administration approved the first vaccine to prevent the disease.
A respected researcher on the “regular” flu as well, Treanor’s led investigations that show the promise of a new type of flu vaccine that could help avert crisis, helping the nation produce vast amounts of flu vaccine on short notice. He’s also a founder of the New York Influenza Center of Excellence, part of a network of centers established by the National Institute of Allergy and Infectious Diseases to protect people against seasonal flu and future flu pandemics.
