A small study of COVID vaccine aftereffects triggers a political and scientific storm

Under normal circumstances, the study of health problems after COVID vaccinations posted online on Feb. 25 might not have generated much controversy.

Its principal authors were well-respected scientists at Yale. The study was explicitly preliminary: Its sample size was only 42 people whose claims to have suffered long-term medical problems after vaccination were assumed to be accurate representations of their medical condition, defined by the researchers as “post vaccine syndrome,” or PVS.

“This study is early-stage and requires replication and validation,” the authors wrote. The study was conducted from late 2022 through late 2023.

Among the limitations acknowledged by the authors are that they couldn’t be sure that the subjects’ ailments might have stemmed from infections with COVID itself, rather than vaccination. Nor could they be sure that conditions other than COVID vaccination might have accounted for the subjects’ illnesses.

Despite those limitations, and the fact that the study was a preprint — published online without first having been vetted via peer review — the paper has been seized upon by anti-vaccination activists and the far right as confirmation that the COVID vaccines are dangerous, despite government assurances that they’re safe and effective. It has been cited by Alex Jones and Joe Rogan.

Misinterpretation of the study’s findings has become so widespread that some scientists have questioned whether it should have been posted at all, much less promoted via a Yale publicity release — not merely because it fed into the politicization of scientific research but because its findings were too premature to warrant publication.

“The consequences of putting out out a press release on a preprint — especially this poor quality study — is wildly irresponsible & does serious harm to scientists & the public alike,” virologist Angela Rasmussen of the University of Saskatchewan posted on Bluesky.

The study’s principal researcher, Yale’s Akiko Iwasaki, has taken to social media to debunk the flurry of misrepresentations online. After the right-wing vaccine critic Paul Thacker posted a tweet stating that the authors had posited that “millions of long COVID patients may actually be vaccine injured,” Iwasaki tweeted a crisp reply: “No. This is not what our study shows.”

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There’s no question that vaccine science has become poisoned with disinformation and right-wing ideology. The anti-science threat only intensified when Donald Trump appointed anti-vaxxer Robert F. Kennedy Jr. as secretary of Health and Human Services.

In a recent interview on Fox News, Kennedy responded to a burgeoning measles outbreak in West Texas — which already has brought about the first measles death of a child in the U.S. in 10 years — by promoting ineffective nostrums such as cod liver oil and steroids. He questioned the safety of the MMR (measles, mumps and rubella) vaccine, which has been in use for more than a half-century and is known to confer lifetime immunity to measles after two doses for the vast majority of people.

The National Institutes of Health, which falls under the jurisdiction of HHS, has terminated grants for research into vaccine hesitancy, according to the Washington Post, even though the Texas measles outbreak has been attributed to low measles vaccination rates in the religious community where the outbreak began.

And at a Senate confirmation hearing March 5, Jay Battacharya, a Stanford professor who is Trump’s nominee to head the NIH, said he endorsed further research on the purported link between the MMR vaccine and autism, even though the link was first posited by a British study that has long been retracted and no evidence of any such link has been found despite decades of intensive study.

The anti-vaccine movement’s targeting of COVID vaccination has long been underway, even thought the vaccines were estimated by the Commonwealth Fund to have averted 18 million hospitalizations and 3 million deaths in the U.S. in just their first two years of availability, during which 655 million doses were administered.

The politicization of anti-COVID policies has led to laws prohibiting mass vaccinations and vaccine promotion in Louisiana and Texas, and a proposal mounted by Gov. Ron DeSantis in Florida. In eight states — Florida, Tennessee, South Carolina, Texas, Iowa, Montana, Idaho and Washington —legislative efforts are underway to ban the mRNA COVID vaccines developed by Moderna and Pfizer, the leading vaccines in the U.S.

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The Yale study’s authors defend their decision to post the preprint online even as a preliminary study of post-vaccine medical conditions. “We were aware from the outset that this is a highly politicized research topic,” co-author Harlan Krumholz, a professor of medicine at Yale, told me by email. “The reality is that vaccine safety — like all areas of medicine — benefits from rigorous, open research, and suppressing inquiry would be counterproductive.”

Krumholz added, “We were fully aware that our research could be misrepresented. That is precisely why we preprinted it — so that the full study could be read and scrutinized in context, rather than discussed based on speculation.... Suppressing studies because of concerns about how they might be misused sets a dangerous precedent.”

That brings us back to the study itself, which aimed to explore what the authors termed “post-vaccination syndrome.” Their goal was to pinpoint what biological conditions might predispose some people to the problem.

It’s true that some people have experienced adverse reactions to the COVID vaccines — as also happens with other shots. “Vaccines are medicines, and all medicines have side effects — even when the net benefit is large,” observes Adam Gaffney, a Harvard medical school assistant professor who has been critical of the study.

Two people listed as co-authors on the Yale paper say they have experienced long-term aftereffects from COVID vaccinations. (Neither was among the subjects of the Yale study.)

Within an hour of receiving a COVID vaccine as a subject of an early clinical trial of a vaccine developed by AstraZeneca in 2020, Brianne Dressen says she began to experience symptoms such as brain fog, neuropathy (the feeling of pain or a pins-and-needles sensation in the limbs) and food sensitivities. “I feel like I’m rolling around in cactus all the time,” she told me. The AstraZeneca vaccine has been taken off the market due to competition from vaccines from Pfizer and Moderna, which are more effective.

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Another listed co-author, retired Southern California gastroenterologist Danice Hertz, told me she began feeling similar reactions after receiving the Pfizer vaccine after it was rolled out to the public in 2021. “I walked into the facility healthy and feeling fine, and within 24 hours I became severely ill. I had severe burning in my face, tremors, twitching; I felt like I was being electrocuted.” Both say these symptoms have improved, but some haven’t fully disappeared.

Both say they had trouble persuading their doctors to examine the connection between their symptoms and the shots. “It was very hard to get medical care,” Hertz says. “Nobody knew anything about these reactions. You really couldn’t get medical care.”

The difficulty of finding medical treatment prompted Dressen to co-found REACT19, a tax-exempt organization that provides grants to patients and providers; Hertz is listed on its website as a research advisor.

Although critics have labeled REACT19 as an anti-vaccine organization, both say that’s untrue — it aims to support research into PVS. Dressen and Hertz both say they are fully vaccinated against other diseases. “We are an organization of 36,000 people, 100% vaccinated,” Dressen says. “In reality this is nothing more than a medical condition, and there should absolutely be nothing political about it. It’s been extremely abhorrent and hurtful for people suffering from chronic conditions to have their illnesses politicized.”

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Still, that leaves open the question of what the Yale study tells us. Its critics say the answer is not much. The term “post vaccination syndrome” itself is a problem, in Gaffney’s view, because it takes as a given the connection between vaccination and the symptoms. That connection needs to be proved, not assumed, he argues.

“By assuming the cause-and-effect relationship,” he says, “you seem to give grounding to a new medical diagnosis that may not actually be a proven cause-and-effect.”

That’s especially so because the described symptoms — chronic fatigue, brain fog, insomnia, and dizziness among them — are not uncommon and often arise from other causes. Indeed, they have often been attributed to long COVID — the lasting symptoms of infection by the COVID virus itself. Not all the PVS group suffered the same symptoms, raising questions about whether PVS can be accurately defined.

As it happens, the Yale researchers found that 26 of their PVS cohort, or about 62%, had antibodies in their system indicating that they had previously had COVID, but only 15 told the researchers that they had been infected at least once. In the control group of 22 people without symptoms, 46% had the post-infection antibodies.

Other critics have argued that the sample size is simply too small to extrapolate any of the Yale findings to the population at large. Moreover, the researchers divided their samples into subgroups based on whether they had been previously infected (27 of the PVS cohort group and 11 of the control group) or uninfected (15 of the PVS sample and 11 of the control group). That arguably makes it even harder to apply the findings to the general population.

The study’s authors don’t disagree that much more extensive research is needed. “This work is still in its early stages, and we need to validate these findings,” Iwasaki told Yale’s publicity department. “But this is giving us some hope that there may be something that we can use for diagnosis and treatment of PVS down the road.... This is far from a final answer on PVS.”

That cautionary note may be lost on the anti-vaccine brigade that has taken the study as virtually the last word on the supposed peril of COVID vaccines. In the current partisan environment, the threat to public health from a concerted movement to undermine the public’s trust in science and vaccines is real.

The authors of the Yale study sincerely see themselves as heralds of empirical science, whatever the political ramifications. “If we only published research that aligns with prevailing narratives or avoids controversy, we would be failing in our responsibility as scientists,” Krumholz told me. “Our obligation is to pursue the truth, even when it is inconvenient.”

But what if the truth becomes not merely inconvenient, but weaponized by unscrupulous actors in a war against the public interest? Unfortunately, we may now have reached that point.