Son, I’ve been avoiding this conversation. But it’s important. It will be difficult and I realize you don’t want to hear it, least of all from me. But there are things you have to know. Please try not to think of this as personal. It’s not about your thoughts or feelings. It’s about the future, how to make decisions, and how to understand our bodies and how they interact with the world. So, here goes.

In March of 2020 the Covid pandemic hit hard. The virus was new, leading governments and companies around the world to work furiously on developing Covid vaccines. The most promising and effective were mRNA vaccines from Pfizer and Moderna, which completed clinical trials of 70,000 people by November of the same year. This was a jaw-dropping achievement, and both vaccines reduced infection rates by over 90%.

The vaccines were quickly made available to everyone, and by June of 2021 more than half of the US was vaccinated. But there were many holdouts. People worried about the safety of a new technology pushed by government, and rushed to market by companies with long histories of unethical, profiteering behaviors. Then, in July, the Delta variant of Covid tore through the US, infecting vaccinated and unvaccinated people alike.

So. . . did the vaccines work?

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The Delta variant extinguished any dreams of herd immunity, showing the vaccines didn’t protect well against Covid infection. Even so, they could still work. After all, humans deal with seasonal influenza and countless other viruses. What made Covid awful was its fatality rate. If the vaccine prevents the severest cases, most importantly deaths, Covid could become just another seasonal virus.

So. . . did the vaccine at least do that?

The two big mRNA randomized trials ran just 6 months each, which is frustratingly short. (Placebo participants were then given vaccine shots, so we don’t have trial data to know long term effects, good or bad). At 6 months, however, deaths were equal between groups: 31 vaccine, 30 placebo. And most of the deaths (29 vs 25) weren’t related to Covid.

For the Pfizer trial, which reported 15 vs 14 deaths, FDA documents actually show 21 vs 17. But this includes the ‘crossover phase’ which came after 6 months. Some people therefore like to say deaths were “23% higher” in the vaccine group. While that’s numerically correct, it’s misleading since a) there was no statistical difference, and b) after 6 months most people in both groups were vaccinated. For the Moderna trial, deaths were 16 vs 16.

These numbers don’t tell us much. Okay, yes, the vaccine trials didn’t find a life-saving benefit. But that could be because there weren’t enough deaths due to Covid (just 2 vaccine vs 5 placebo) among participants. Or maybe the vaccine doesn’t save lives overall. Maybe it prevents some Covid deaths but causes others, for instance due to sudden cardiac arrest or heart problems (the National Academy of Science looked, and couldn’t say yes or no). We may never know, both because the studies were cut off at 6 months and because Pfizer and Moderna, even today, refuse to make their data public.

In any case, we should admit the obvious: It feels weird that, in trials done during the peak of Covid fatalities, people who got vaccinated died as often as people who got a placebo. That’s either an unfortunate and misleading anomaly (i.e. the trials were too small), or it’s an important signal of failure lost in the noise of politics and opinion.

Meanwhile, many other studies have concluded the mRNA vaccines save lives. Sadly, they’re all hopelessly shitty. Excuse my French, but let us be honest and blunt: So-called ‘real-world’ data is neither real nor data. It is, at best, the plural of anecdote. The ragtag collection of studies making this claim all suffer from healthy user bias (in which people who choose to be vaccinated are predictably much healthier at baseline than people who choose not to get vaccinated, and therefore die less) and are easily challenged. This includes a devastating, if barely noticed, takedown in the pages of the New England Journal of Medicine.

But, alas, even a naked moment of research verité doesn’t prove that ‘real-world’ study findings were wrong. It just means their data can’t answer the question. And in fact, on an ecological scale it’s likely the vaccines did save millions of lives. The timing of the pandemic’s last gasps—as vaccines phased in—and the statistically powerful finding that people who died of Covid were overwhelmingly unvaccinated, are both strong circumstantial arguments.

But that is what they are, and we should be honest about it. We should be bashful when saying the vaccine ‘works’, and clear about the uncertainty. Particularly when data from the trials show roughly 1 in every 1,000 people experiences a serious harm from the vaccine, like appendicitis, myocarditis, gall bladder problems, and more.

Therefore we must accept that it isn’t crazy, wrong, or conspiratorial to worry the vaccines may not save lives, or could be more harmful than helpful for some. Particularly now, when most people have natural immunity, which is as good as vaccine immunity.

Therefore the decision to be vaccinated can be personal, not communal. For most people under the age of 30 the flu is more of a life-threat than Covid, and the Covid vaccines are way more likely to be harmful than helpful. For those 30 to 60 it’s close, but Covid may be worse than flu as their age rises. And over 60, Covid definitely is the bigger threat.

Which explains why, for instance, most European countries only recommend Covid vaccination for the elderly—a reasonable, not insane, approach.

Does the vaccine work? It depends. It probably won’t keep you from getting Covid, and if you’ve had the infection it’s likely redundant. But if you haven’t, or you’re getting along in years, it’s possible—though not definite—that it could reduce your chance of dying from Covid.

So. . . son: Be honest and be true, and respect people. It’s their body, it’s their choice.

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