Photo by Queen's University.
Flu season is upon us, and perhaps you are dismayed to hear that last year some people had gotten the flu vaccine and still came down with the flu. (This happens every year, but it seems more real when it happens to you or somebody you know.) But the flu vaccine is still working. Here's what you need to know.
The Vaccine Is Probably Way More Than 10 Per cent Effective
A few news articles trumpeted a 10 per cent number as evidence that the flu vaccine is only barely working. But that was really from a report that the vaccine was only 10 per cent effective against one strain of flu (an H3N2 type), and in Australia. If you want to know how well the shot works, you need some more information.
The CDC reports that 2017's vaccine had the same H3N2 component, and that the H3N2 circulating this year in the wild seems to be similar to the H3N2 from 2018. That means we can make a good guess at this year's vaccine effectiveness by considering those numbers. And it turns out that in 2018, the vaccine was about 32 per cent effective against H3N2.
This year we've got a lot of H3N2 in circulation. It's represented by the red bars on the chart above. But it's not the only type of flu out there, and the others tend to be a better match for the vaccine anyway (H3N2 is a particularly slippery little virus). Over the past ten years, flu vaccine effectiveness has ranged from 19 per cent to 60 per cent. This year might be on the lower end, but it's really too soon to tell.
But but but…
You should know these by now, but:
- No, the flu vaccine can't give you the flu, any more than swallowing a watermelon seed can make a watermelon vine grow in your belly. It just doesn't work that way.
- If you got the flu shot and then got the flu, congratulations, you're a statistic. But plenty of people got the flu shot and didn't get the flu, and didn't spread it to babies or old people or cancer patients.
- The flu shot helps you respond better to the flu, so even if you get sick, you're better off with it than without it.
- There is little to no downside to getting the shot, which is why it's recommended for almost everyone from six-month-old babies on up. Read over the CDC's recommendations here. Babies need two shots, old folks need a high dose, and the nasal spray version isn't on offer because that one wasn't effective in past years.
- It's not too late. Your local pharmacy might be out of flu shots, so use vaccinefinder.org to find a place that still has some in stock. But immunologically, it's still worth getting a shot now if you didn't get one before. (If you did get one earlier this season, sit down. You're done.)
- Big Pharma doesn't pay me to say any of this. I write about the benefits of the flu vaccine because it's got good ROI: you spend a few minutes out of your day and deal with a sore arm and some insurance paperwork (PSA: it's free), and in exchange you have a pretty good chance of keeping flu viruses out of circulation.