For some reason, I thought a potential side-effect of flu vaccines was Guillain-Barre syndrome. I mean, its super super rare, but I thought that was a stock-standard potential adverse event. Apparently, thats not the case– whether Guillain-Barre syndrome is an actual side-effect of influenza vaccines is a controversial subject (not just with anti-vaxers, or hoaxers, but like, the real world). It might have just been a freak accident in one years batch of vaccines in the 1970s, it might have been a statistical fluke, it might not be anything.
But the field itself is concerned about adverse effects of vaccines, so instead of threatening researchers, they investigated whether there was a connection between Guillain-Barre syndrome and the swine flu vaccine (hehehe, remember swine flu? good times…).
In a source population of around 50 million people in Europe we could not find any association between adjuvanted pandemic influenza A (H1N1) 2009 vaccine and Guillain-Barré syndrome (adjusted odds ratio 1.0, 95% confidence interval 0.3 to 2.7).
In retrospect, the swine flu vaccine was safe. Yay!
Certainly thats comforting, but whats also comforting is that researchers looked. They looked at the data, and if something was amiss, we would have a reason to investigate what was causing the problem, thus figure out how we can fix the problem. You dont know unless you look, we looked. I was speaking to an old friend recently, and he asked whether this sort of thing happened, or whether researchers just say “Meh, it got FDA approval” and dropped it. Its comforting to know that isnt the case– Its not just about safety during initial clinical trials, researchers keep an eye on these kinds of things once drugs and vaccines are on the market, too.