Read on Twitter
We're going to start seeing a lot of these types of stories in the weeks and months to come, so a few very important reminders that we all need to keep in mind about side effects, risk, and risk calculations: https://twitter.com/neolithicsheep/status/1339560336773566464
1) A bad thing that happens after someone gets vaccinated isn't necessarily a reaction to the vaccine. The example in the article about the kid who had a seizure 5 minutes before a vaccine is a great example of what I mean.
In any large enough group of people receiving a vaccine, there's going to be a person who would have had a heart attack that night no matter what. That doesn't mean the vaccine causes heart attacks.
When you're dealing with populations, you can't just say "this person died that night, the vaccine killed them". You have to look at the expected heart attack rate in your sample and see if the risk is higher in the group that got the vaccine.
That's part of why Phase III trials happen, and happen with placebo groups: it gives you a control to compare against.
2) You also can't compare the risk of adverse events from a vaccine to doing nothing: you have to compare it to the risk from the disease the vaccine prevents. We are really bad at this. We tend to view any adverse effect, even mild ones, as reasons to avoid the thing.
But it's all a risk calculation. To use nonsense examples and numbers to drive my example home: if a vaccine had a 50% chance of turning your skin blue for a week, but the disease has a 90% chance of killing you, fuck it, you take the vax and embrace temporary smurfhood.
Where we get bad at it is where the adverse effects are rare but serious. If that same hypothetical vaccine had a .005% chance of life threatening anaphylaxis but the disease has a 5% chance of killing you, people will start to get hesitant.
But to figure out the right thing to do there, you have to look at your chances of getting the disease, and also look at ways to mitigate the risk. If the disease is circulating widely, maybe you still get the vaccine, just in a hospital setting to address any reaction quickly.
This is why tuberculosis isn't in the standard vax schedule for all adults, btw, despite the increase in drug resistant TB: if you have a TB vaccine, you'll always test positive for the disease afterwards. That prevents future diagnosis if the vaccine doesn't work on you.
The TB vaccine is one of the lowest effectiveness we have: it prevents TB in about 20% of the people who receive it. So if we vaccinated everyone, the number of future cases of TB that would go undiagnosed is greater than the number of infections it would prevent...
...because TB tends to only appear in certain areas in the US and the baseline chance of an average person being exposed to TB is very low. For those people, it's more valuable to be able to rely on a TB test in the future if they do catch it despite the odds.
The calculations change when you're in an environment with higher number of TB infections, where your risk of being exposed is much higher. If you know there's a 100% chance you'll be exposed to TB, the 20% protection of the vaccine starts looking better, even if it means...
...that if you start showing symptoms, they'll have to assume you have it and treat you for it no matter what instead of being able to confirm with a test before starting the treatment. You get the picture: every decision has to be weighed carefully like that.
(For the record, with how severe COVID is, how much community transmission we have right now, and how overwhelmed our ICUs are nationwide, personally I would accept A LOT of risk from a COVID vaccine, but fortunately it looks like there isn't much risk at all.)
3) If it does turn out that there's a rare but serious side effect or allergic reaction to a COVID vaccine, that will not prove the vaccine was wrong to be approved, that anyone "cut corners", or that anyone in the process was negligent.
(It also wouldn't prove there WASN'T negligence, that anyone didn't cut corners, or that the vaccine was right to be approved, but people are way more likely to take the former set of positions than the latter.)
Every drug or vaccine has the potential to have side effects that only show up once you start giving it to a lot of people. Human genetic variation is wild and our systems interact weirdly with each other. You can only spot those interactions at a massively wide scale.
To go back to the wild invented examples: Say there's a rare disease called Exampleitis that's found in 1 in 1,000,000 people and your country has a population of 500m. You'd expect 500 cases of Exampleitis in the country...
...but since it's so rare, maybe 100 of them are diagnosed. If a vaccine has a 50% chance of causing anaphylaxis in someone with Exampleitis, it's gonna take a LONG time to figure that out: 50 reactions would be in diagnosed people and 200 would be in undiagnosed people.
Anyone looking at "people who had anaphylaxis after the vax" would probably dismiss Exampleitis as a factor, because over 3/4ths of the people who had reactions don't even know they have Exampleitis for it to go in their records.
Multiply this by a billion possible conditions and you start to see the problem. A lot of side effects and reactions only start to become apparent when we give the drug to a large number of people, and a lot of times we don't even know why they happen.
For example, Cipro, the antibiotic, has a very rare chance of causing tendon rupture in some people. We don't know why! We have no idea what causes it! But Cipro is still available, and it still gets prescribed, bc we need every antibiotic we can get and it's very effective.
It's even the first antibiotic in line for me despite my various joint and tendon issues, because I react so badly to so many others and the small risk of tendon problems is better than the guaranteed mast cell problems from other antibiotics.
All of this is to say: We're going to see a lot of bad science reporting that doesn't understand relative risk and it's going to be exploited by anti-vaccination activists to try to convince you this vaccine is Bad and Dangerous.
Seizing on these ways that people misunderstand relative risks, emphasizing infinitesimal chances of adverse reactions, and aggressively exploiting our inherent inability to accurately assess the probability of very rare risks is a common tactic of the antivaccine movement.
Some of the people doing it genuinely misunderstand risk assessment and genuinely believe what they're saying. Others are doing it for personal gain. Andrew Wakefield, who destroyed public trust in the MMR vaccine, did so to sell his own competing vaccine, for instance.
There will, inevitably, be people who shouldn't get any particular COVID vaccine, and it's going to take time to identify exactly who those people are, because of the problem in 3 above: some risks only become apparent at massively large scale.
This will not mean the vaccines weren't tested thoroughly; it will mean that it's impossible to discover these things in testing because the test population you need to find them is indistinguishable from just vaccinating everyone anyway.
To anyone hesitating to get the vaccine because of how quickly it was developed: the reason it was available so quickly is because of a decade of work on vaccines for similar diseases that researchers could build on. It wasn't made in a year, the work was mostly already done.
The rest of the speed came from the massive amounts of money we threw at the problem being able to speed up the administration and enrollment of the trials, and from manufacturers getting $$ to start production of their candidates before they even knew if they'd work...
...so that if they DID work, they'd already have lots of doses available, and being willing to throw away that $$ if it turned out not to be effective after all. (This is where the Bill Gates conspiracy comes in: he funded a lot of that pre-manufacture, just in case.)
But all the trials were done publicly, with publicly available data, and --most importantly -- many manufacturers, Pfizer and Moderna among them, publicly committed *ahead of time*, before beginning the trials, to what results they'd accept as a success.
This public precommitment is the gold standard for randomized controlled trials, because it means you can't look at the data and say "well, the statistics show it's effective in left handed people age 31-40" or however you can slice the data to show "effectiveness"...
...that's really just statistical noise and normal variation. Instead, they said ahead of time what results would be considered a success, and they did so publicly and in ways that were peer reviewed by independent scientists globally.
This *should* happen with every drug trial, but it's a lot more rare than it should be, unfortunately. Still: it's a very solid indicator the trials were conducted properly and the results were real, not made up. Some trials didn't do that, and sure enough their data is weird.
I know that the last four years have destroyed a lot of the remaining confidence we all had in government and government agencies, and I see a lot of people saying they aren't going to trust any vaccine Tr*mp's FDA approved. I get it. I really do.
But if a specific vaccine candidate was trialed with public precommitment and global peer review, it's a lot more trustworthy than you would think, and the FDA approval isn't even really a factor in how much we can trust it. Science that happens in the open is stronger science.
The tl;dr of an extremely long thread: Pay no attention to any article talking about vaccine side effects that doesn't discuss relative risk and evaluate any risk against the disease itself, and remember that we as a species are collectively fucking terrible at risk assessment.
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