With the rapid spread of COVID-19’s Delta variant, more than twice as contagious as prior variants, hospitalization and mortality rates are once again on the rise across the United States and around the world. According to the U.S. national public-health agency, the Centers for Disease Control and Prevention, newer victims are overwhelmingly among the unvaccinated, with less than 0.1 percent of fully vaccinated people having experienced a “breakthrough case” of the virus—and a smaller percentage still having experienced a case resulting in hospitalization or death. Yet less than 50 percent of the U.S. population is fully vaccinated. The reasons behind these numbers are complicated—and complexly related to a highly polarized political environment—but one of the ideas in high circulation among “anti-vaxx” skeptics is that the vaccines are “failing” against the Delta variant. Tucker Carlson, maybe the most influential voice on America’s contemporary cultural right is just one amplifier of the idea, which continues to replicate across mainstream and social media: “Weird how many vaccinated people seem to be spreading the virus at this point.” How has this idea managed to get traction?
According to James Hamblin—a physician specializing in preventative medicine and public health, a lecturer at the Yale School of Public Health, and the author of Clean—all the forms of political pressure and media manipulation that have become common drivers of misinformation in contemporary American life are part of the answer; but a significant part is how easily the appearances of evidence in health and medicine can be deceiving. Understanding the cognitive frameworks behind an idea like vaccine failure isn’t, as Hamblin illustrates, simply a matter of understanding ignorance or bad faith; it’s a way of understanding an important dynamic in vaccine skepticism—and how vaccination advocates can engage with it more effectively.
Eve Valentine: What do people mean when they talk about vaccine failure?
James Hamblin: During the rollout of the vaccines, public-health advocates and doctors used a lot of language to convey how effective vaccines are at stopping the virus and ending the pandemic—and that language was both true and potentially a bit oversimplified, in a way that could lead people to believe that there would be zero instances of post-vaccine infection and breakthrough cases.
People actually mean different things by vaccine failure. The technical definition would be when you actually become sick with the disease against which you were vaccinated, as opposed to, say, briefly carrying some of the virus in your nose. But some will use the expression “vaccine failure” more casually, to say that the vaccines aren’t working in the way that they were promised or that they expected—which they see as a sort of absolute protection, as if you were coated in a nonstick anti-virus armor.
Seatbelts are a better comparison. If your seatbelt breaks during an accident, and you go flying through the window, then that’s a seatbelt failure. But if you get rear-ended and the seatbelt works, yet you still have some injuries, that’s not a seatbelt failure. That’s actually the seatbelt doing its job. Which could seem confusing if you were thinking, “I was wearing a seatbelt, so there should be zero injuries whatsoever.”

Valentine: So, it’s not that there are simply no instances of infection or death that you could describe as vaccine failure; it’s that there’s no evidence of vaccine failure at scale?
Hamblin: It’s something that happens in medicine. You can point to single instances of people becoming very sick and use that as a framework to highlight individual cases, where, indeed, the vaccines failed—the person got very sick despite being vaccinated—then imply that it means the vaccines don’t work.
But that’s a much bigger takeaway than the truth, which is that there are some vaccines which that sometimes happens with, but that doesn’t mean they’re not working. In fact, it’s just the normal and expected outcome.
Valentine: How does the narrative of vaccine failure work, then, despite the contradicting evidence?
Hamblin: Advocates of the idea tend to focus on individual case studies of adverse effects or breakthrough cases—either deliberately, or, just because our brains tend to focus on narratives of individuals and read into them, in this case, that the vaccines aren’t working. So you can draw on a base of facts, you can highlight these outlier cases, and you can come to believe that we’re seeing vaccine failure.
You can even highlight those instances in bad faith to call out people who told you that the vaccines do work—for example, people like me, who made simple statements like, If you get vaccinated, you’ll be protected from the coronavirus, without the proper caveats, and then use that to twist facts by saying, You can’t trust anyone who told you that you’d be protected, because, look, there’s this number of people who got sick despite being vaccinated.
Advocates of the idea tend to focus on individual case studies of adverse effects or breakthrough cases—either deliberately, or, just because our brains tend to focus on narratives of individuals and read into them, in this case, that the vaccines aren’t working.
That’s the really malicious version, where you’re sowing distrust against all science, or all vaccines, or anything that might come out of the mouth of people who are public-health officials in the future. That’s the really dangerous twisting. It’s absolutely important to highlight and report on breakthrough cases, so everyone can understand their exact risks. But it becomes malicious and dangerous when these cases are taken out of context and used to undermine the credibility of doctors and public-health officials generally.
Valentine: In this context—with all its vulnerabilities to malice and informational danger—we’re seeing troubling data on the Delta variant, other emerging variants, and “breakthrough” infections for the fully vaccinated. How do you make the case to someone who’s hesitant to get vaccinated because the vaccines “don’t work for Delta anyway”?
Hamblin: I think the most effective thing that can be said right now is simply to point to the data of who is being hospitalized and dying in the United States. And it has been consistently in the 90-plus percent range that people who are hospitalized with serious COVID-19 infection, or who are dying of it right now, are unvaccinated. A simple point like that is the most powerful and effective way to demonstrate what you’re talking about.
It also admits that as long as the virus is spreading widely, and continuing to evolve, vaccinated people are still at some risk—it’s just far, far lower than the risk of going unvaccinated.

The risks of adverse effects are also fleeting. Everything we do in health and medicine has the possibility of adverse effects—even the most time-tested things. There’s no medication and no procedure that doesn’t come with the possibility of something going wrong—or of some negative symptom that comes as an effect of the thing actually working. Everything involves a risk-benefit calculation, and the risks of side effects, or adverse effects, from vaccination is nowhere near comparable to the risks you undertake if you forego vaccination.
It’s a great question. I wish there were more people who are wanting to actually engage in that sort of conversation.
I think the most effective message is to look at the data on who’s currently hospitalized and who’s getting very sick in the United States. If you were to do that, and if you were to force people into a choice between being in the group that has a very high risk of hospitalization, and possibly even deaths from COVID—which happens to be the unvaccinated—or being in the vaccinated group, where you have a very low risk? That’s the choice.
There are some who allow for this magical thinking in which there’s some other path, where you just don’t get vaccinated, and you don’t get sick, and everything is open, and everyone is fine. Any effective approach involves forcing debate into the realm of reason where we can talk about different approaches to this, but you have to say the pros and cons of each one, and no one gets the free pass of just promising that everything will be okay.
Everything we do in health and medicine has the possibility of adverse effects—even the most time-tested things. There’s no medication and no procedure that doesn’t come with the possibility of something going wrong—or of some negative symptom that comes as an effect of the thing actually working.
Valentine: In the U.S., the Pfizer vaccine was officially approved by the Food and Drug Administration this past week. The FDA’s vetting process for the vaccines seems to be a focus among a lot of skeptics, whether because they see it as having taken too long, or not long enough, or on account of the idea that the FDA is somehow insufficiently independent of the drug companies that developed the vaccines. What would you want people to understand about that vetting process and how the FDA is conducting it?
Hamblin: The process is extremely thorough, and it is the reason—despite overwhelming evidence that the vaccines are working, safe and effective—that it took so long. In fact, it was frustrating to a lot of experts that it did take so long. But the FDA goes through the case files of tens of thousands of patients to make sure there’s absolutely nothing they’re missing.
They operate as a sort of an antagonist to the drug companies. Even in a situation where we want this vaccine to work, the job of the FDA is to start effectively from the assumption that a drug company is totally making everything up, and that all of their own studies are fabricated, and you have to reverse engineer all of the results and try to make sure that everything is as they say it is.

They also ensure that the production facilities are up to a certain standard, so that the product the drug companies claim they’re producing is indeed consistent with the product that was tested in the clinical trials. So the fact that the Pfizer approval, for example, took as long as it did should be reassuring to people.
This is an intensive, protective mechanism that goes beyond merely re-running statistical calculations. It goes back and determines if there was any bias, analyzing people who were put into placebo or experimental groups and how they were reporting their symptoms. They determine whether there’s any reason to think that there could have been any symptoms that patients wouldn’t have reported but that the public should know about. It’s an intensive audit. It took this long because it is so thorough. So, I think anyone who is waiting on FDA approval to get vaccinated should take heart and proceed immediately.
Valentine: There is also skepticism and confusion about the idea of boosters. In your newsletter, The Body, you recently indicated that we can’t yet be sure whether people other than the immunocompromised or the elderly would need boosters. How, in your view, should we be thinking about boosters and what they mean for the efficacy of the vaccines overall?
Hamblin: This is extremely complex and I do worry about pitfalls that are similar to what we discussed around breakthrough cases, which is that if people are told they need a booster, they might feel that they’d been misled about whether the vaccine itself was going to protect them.
Even in a situation where we want this vaccine to work, the job of the FDA is to start effectively from the assumption that a drug company is totally making everything up, and that all of their own studies are fabricated, and you have to reverse engineer all of the results and try to make sure that everything is as they say it is.
In fact, vaccines are still protecting almost everyone very well—and would very likely continue to do that for much longer than the eight months suggested for the booster. There’s certainly a subset of people who’ll benefit from a booster. Making them available to everyone, and the recommendation that people in the U.S. should get them after eight months, is, as I understand it, a matter of simplicity—because stratifying all the different categories of who should qualify for a booster, and how and when, would just be very difficult on a landscape where people are already confused and already find the public-health guidance to be unclear.
But the fact of this recommendation itself doesn’t mean that the vaccines aren’t working for the majority of people. For a youngish, healthy-ish person, getting a booster right now, or at eight months, is erring on the side of extreme caution. This sort of recommendation—not unlike the time it’s taking the FDA to approve the vaccines—should be taken as an indication that as much as possible is being done to keep you protected, rather than that the vaccines aren’t working as they should.
I’d say the Delta variant has thrown a wrench into this, not because the vaccines are ineffective against Delta—they’re still very effective—but because the virus’s capacity to evolve suggests that it will continue to evolve. Which is precisely why we’d want to make sure our immune systems are as fortified as possible, in the event we do end up seeing a variant that can escape the immune mechanisms the vaccine has produced.

Valentine: Looking at the problem globally, why should the U.S. invest resources in a booster when many parts of the world aren’t even getting a first dose, let alone a second? To the extent that managing the pandemic down is a question of global herd immunity, wouldn’t it be in the better interest of the U.S. to invest in exporting—or enabling the global production of—first and second doses rather than distributing third doses at home?
Hamblin: It’s a delicate balance. Even from a purely selfish perspective, the U.S. should want everyone in the world to get vaccinated. And we are donating some doses to countries in need. But there is certainly an absurdity in the fact that we’re going to have young, healthy people getting booster doses in America when at-risk groups in many other parts of the world haven’t had a single dose. There is no way to justify that.
And it won’t be solved by giving one-time donations throughout the world. We need an entirely new system of vaccine production and distribution. The U.S. government needs to open up, help with technology transfer, help with sharing the vaccine, sharing the recipes, and help build up production capacity around the world. That would be the meaningful gesture. The fact that we’re not doing this, layered on the fact that we’re going to be recommending that healthy people get a booster dose is kind of impossible to justify—and will not reflect well in the eyes of the world.
The Delta variant has thrown a wrench into this, not because the vaccines are ineffective against Delta but because the virus’s capacity to evolve suggests that it will continue to evolve. Which is precisely why we’d want to make sure our immune systems are as fortified as possible.
Valentine: Another source of skepticism, of course, is about the pharmaceutical industry itself. With a profit margin of 60 to 80 percent a dose, what consequences, if any, do you see from the pharmaceutical companies’ incentives for the effective and equitable distribution of vaccines—whether across the U.S. or around the world?
Hamblin: The system for vaccine production is one where pharmaceutical companies expect enormous profits. Accordingly, they have received enormous profits. I understand why that creates skepticism among some people about the vaccines themselves. It also leads to massive inequities, where countries like the U.S. can swoop in and purchase all the doses they want and outbid other countries.
The pharmaceutical companies are acting in their rational business interests to sell to people who can pay the most money. That they’re giving the vaccines at lower prices to countries that can’t pay as much as the U.S. can be seen partly as an act of benevolence—but also, obviously, the shareholders of these enormous corporations are not going to be happy if a CEO sells the vaccines at a fraction of their price to a country that can only afford to pay that fraction. Such a CEO would quite likely be ousted if such a ton of money were left on the table.
So the problems here are with the system, not with people within the system abusing it. It’s working actually exactly as intended. And the wake-up call is that, if you want a globally effective and equitable distribution of vaccines, this current system is not how you achieve it.

Valentine: A striking number of Republican leaders have supported anti-vaxx messaging, largely in the language of personal liberty. Who are the thought leaders out there generating anti-vaxx messaging based on the idea of vaccine failure—and what do we know about the populations most receptive to it?
Hamblin: Certainly, some Republican leaders have been very supportive of vaccination, but many have been focused more on the idea of mandates—and have been too silent on the need for people to get vaccinated.
There’s legitimate debate about how mandates should work. And that might play into certain ideological beliefs about the role of government. But if you spend all of your time talking about how mandates are bad, and you’re not extremely clear that vaccines are good, and not harmful—and that everyone should get vaccinated—the ultimate takeaways get rolled up together in people’s minds.
There are some prominent voices who’ve been just against mask mandates, or against vaccine mandates, or against school and business closures. But if you don’t want a vaccine mandate, how would you suggest that people get vaccinated? What is your plan for making sure we reach some critical threshold in having the population as a whole vaccinated? What are you actually proposing? Because I think the truest definition of liberty would be that you can go outside and do what you want without fear that you’re going to contract or spread a potentially deadly illness.
