“I got the flu shot but got sick anyway!”
I’ve heard that line so many times. Without running off on too long a rant, people call any bad cold “the flu”, but I haven’t heard of anyone who said “I had a laboratory-confirmed diagnosis of influenza A or H1N1 even though I got the shot!” The flu shot will protect you from a few strains of the flu for that year. You can still catch a cold, or strep throat, or a bacterial sinus infection — or even a less-common form of influenza that wasn’t included in the shot. Indeed, I’m sitting here with a nasty cold even though I got the flu shot. Fortunately, I’m currently participating in a study that seeks to test these types of claims, so I should know in a few weeks what the results from my nasal swab are, and whether I actually have the flu or some other nasty virus. Right now in Toronto, about a quarter of monitoring nasal swabs are coming back positive for influenza; I don’t know how many of those people had the shot, but it makes for a lot of sick people who really just have colds.
I heard of a very clever, tongue-in-cheek test to see whether you have actual influenza or just a seasonal cold called “the fifty-dollar test.” Simply go to a sick person’s bed, and put some money at the foot of it. If they say “fuck it, I am too sick to reach down to the foot of the bed and get that money” for anything under a $50, they have the flu. If a $20 bill will motivate you to move your stuffy, feverish head and aching body enough to grab that free money, you just have a cold.
This year’s flu season seems a bit worse than usual, with H1N1 reappearing and striking the young and otherwise healthy people who usually skip through flu season. Many people are now (belatedly) rushing for their flu shots, leading to supply issues. If getting vaccinated at these higher rates becomes more habitual for the years to come, that’s going to help increase herd immunity and make the average future flu seasons less severe.
As our regular flu season becomes tamer, with more people vaccinated and fewer people infected each year, we might be at an increased risk of hearing “I got the flu shot but got sick anyway!” Because of course we could have one bad year where the scientists determining which strains to include in the vaccine miss a big one, and it runs through the population.