The CDC Owes Parents Better Messaging on the Vaccine for Kids

On June 23, an advisory committee to the Centers for Disease Control and Prevention met to discuss, among other topics, vaccine-related cases of myocarditis, which have hospitalized hundreds of adolescents. Evidence of a correlation between the condition, an inflammation of the heart muscle, and the vaccines had been mounting for months. Numerous countries had altered or withheld recommendations for pediatric vaccination, with some citing an ambiguous risk-benefit. One day after the committee meeting, however, CDC director Rochelle Walensky went on TV and calmly reassured viewers that there was nothing to worry about: Vaccinating kids age 12 and up, at the full dosage and same schedule as adults, should continue with alacrity.

Walensky cited a string of statistics that showed “the benefits of vaccination far outweigh any harm.” But some epidemiologists, public health experts, pediatricians, cardiologists, and other scientists dispute the CDC’s numbers, characterizations, and conclusion. The agency, they variously contend, is both exaggerating the risks of Covid-19 to young people and underplaying the potential risks of the vaccine to them. Much data that would support the CDC’s declarations are either unknown, unrevealed, or far messier than the agency and its director portray. And the data that are known and clear have been projected through a specific lens with blunt certainty. The absolute risk of the vaccine still appears to be extremely small for young people but, on balance, when the data are seen through a different frame, the relative individual risk from vaccination, particularly for healthy young males, may be higher than it is to not be vaccinated at this time.

There is no debate among most experts critical of the CDC about the value of vaccines on a societal level to help usher in the end of the pandemic, which is the ultimate goal of the vaccine. Rather, the matter at hand is the CDC’s messaging, which fails to help parents and children make properly informed decisions about the vaccines on an individual level. As Stefan Baral, an epidemiologist and physician at Johns Hopkins, recently tweeted, “One can be both very pro-Covid-19 vaccination and also be worried about the individual risk:benefit profile of Covid-19 vaccines in <16 yo.”

First, the link between the mRNA vaccines and myocarditis, particularly in young males, is sufficiently clear that the FDA revised its vaccine fact sheets to include a warning about it. As of June 11 (the latest date most data were collected for the meeting), 128 cases within seven days of the second dose had been reported in boys aged 12 to 17, when the CDC’s expected number for that same population was zero to four cases. VAERS, the reporting database for vaccine-related adverse events that these statistics are drawn from, has limitations. Some portion of the events reported may be unrelated to the vaccines. But the differential between expected and observed cases within certain cohorts is the statistical equivalent of a blaring siren. (A detailed analysis in Israel estimated the incidence of myocarditis following vaccination in young males to be around one in 5,000, equating to 200 cases per million.)

The CDC, however, wants to make the case that the arresting numbers above only present an illusion of bad stakes for young people, in particular young males. On Good Morning America on June 24, Walensky said, “If we have a group of 12- to 17-year-olds who we're working to vaccinate over the next four months and can vaccinate 1 million of them, we could expect 30 to 40 of these mild self-limited cases of myocarditis … If we were to vaccinate all 1 million we would avert 8,000 cases of Covid, 200 hospitalizations, 50 ICU stays, and one death."

How did the CDC arrive at “30 to 40” cases? In the advisory committee meeting a slide was presented that showed that within 7 days following the second dose males aged 12 to 17 had a rate of 62.75 myocarditis cases per million, whereas females had a rate of 8.68. Averaging the two rates yields 35.72 cases. Yet the rate for young males is more than seven times that of young females. Lumping together two easily delineated cohorts, especially when data show a wildly disproportionate risk for one group, as Walensky did, “is epidemiologically misleading,” said Tracy Hoeg, a physician and epidemiologist who coauthored a study published by the CDC this year, and who is researching myocarditis data with Allison Krug, also an epidemiologist. “If there is a clear pattern that differs from one sex to another,” Hoeg said, reporting the two rates together “obscures the true findings.” It both downplays the risk to young males while making the risk seem higher than it is for young females. A summary slide shown at the meeting similarly, yet even more consequentially, merges not just sexes but also multiple age cohorts, creating a macro coed group of 12– to 39-year-olds, with a rate of 12.6 cases per million second doses, further burying the higher rate (of 62.75 cases) of myocarditis for young males.

Describing the cases without exception as “mild” may also be misleading. A review of myocarditis reports of young males in VAERS finds numerous cases with potentially serious symptoms, including reduced ejection fraction (the measurement of blood pumped out of the heart) as low as 35 percent, which can indicate heart failure; myocardial fibrosis (a scarring of the heart, which also can lead to heart failure); and patients on vasopressors to raise low blood pressure. None of these conditions would typically be considered mild, said Adam Zucker, a cardiologist at Massachusetts’ Brigham and Women’s Hospital.

Many hospitalized patients with post-vaccination myocarditis were in the ICU or PICU for days, some of them on morphine. Requiring intensive care and narcotics, or, frankly, being in the hospital at all, is not a condition most people would associate with the word “mild,” even if some clinicians may describe it this way. Even on that point there is some dispute. Anish Koka, a cardiologist in Philadelphia, put it plainly: “There is no such thing as mild symptomatic myocarditis that puts a young person in the hospital.” He continued, “If you want to redefine ‘mild’ in the context of the pandemic, fine, then say you are doing that. I’m not against vaccines. But we need to be nuanced about how we talk about this.”

The latter half of Walensky’s statement illustrates the CDC’s main argument, that vaccinating 12- to 17-year-olds will net fewer hospitalizations than we’d otherwise see if they were unvaccinated. Yet there are several errors in this calculation. Most strikingly, Walensky only compared incidents of vaccine-related myocarditis with Covid-19-related hospitalizations for 12- to 17-year-olds. Yet, when running a cost-benefit analysis of vaccinating a particular group, what matters, obviously, is the totality of serious adverse events following vaccination, not just myocarditis.

A slide presented during the meeting showed that 0.3 percent of 12- to 25-year-olds (which of course includes 12- to 17-year-olds) have landed in the emergency room following vaccination (0.1 percent after the first dose, and 0.2 percent after the second dose). And 0.3 percent of 1 million, the total number of vaccinations in Walensky’s model, is 3,000. In other words, the CDC is suggesting that within this group, it is preferable for 3,000 12- to 17-year-olds to go to the emergency room after getting vaccinated than for 200 12- to 17-year-olds to be hospitalized from Covid-19. (It’s worth noting that visiting the emergency department is not the same as a hospital admission, and perhaps some portion of the visits were unrelated to the vaccine, but even if 90 percent of the ER patients weren’t admitted, that still would equate to 300 admissions, more than the 200 for Covid-19 infection.) Moreover, as two peer-reviewed studies in a journal published by the American Academy of Pediatrics found, at least 40 percent of pediatric Covid-19 hospitalizations were for patients in the hospital merely with Covid-19, not from Covid-19, meaning the 200 hospitalizations Walensky is referencing may really be around 120.

There also is a highly relevant factor that was left out of Walensky’s cost-benefit analysis. According to the CDC’s own data, 70 percent of 12- to 17-year-olds hospitalized for Covid-19 had underlying medical conditions. Whereas the evidence suggests the majority of young males with post-vaccination myocarditis were otherwise healthy. This detail matters, since it changes the risk calculation on an individual level. The risk-benefit for a 14-year-old girl with underlying conditions (putting her at higher risk for severe Covid) to be vaccinated, for example, is very different from that of a 14-year-old boy with no underlying conditions.

Germany is recommending that only 12- to 17-year-olds with preexisting conditions should get the vaccine. Denmark has approved the vaccine for 12- to 15-year-olds but is waiting until September, after all adults have been vaccinated to offer it to them. The UK’s Joint Committee on Vaccination and Immunisation has put off making a decision about adolescent vaccination until later this month. Norway, Ireland, Finland, Belgium, Portugal, Greece, and Iceland have either not approved pediatric vaccination or have recommended it only for adolescents at high risk. Some of the decisions by some of these countries are based, in part, on supply and logistics, but many have noted the cost-benefit of a low risk of Covid-19 and potential risks related to the vaccine for adolescents.

One of the oddities of the CDC’s recommendation, beyond the calculations it’s based on, is its lack of consideration of alternate vaccination approaches for adolescents beyond the same exact dosage and schedule as adults. The CDC’s analysis “assumes that single doses of mRNA vaccines have 0 percent effectiveness at preventing Covid-19 associated hospitalization,” wrote Wes Pegden, a mathematician at Carnegie Mellon University.

While many media reports of a study published by the UK’s public health agency in mid-June highlighted its finding that two doses of Pfizer’s vaccine were 96 percent protective against hospitalization from the Delta variant, many failed to mention that it also found that one dose was 94 percent protective. Considering the benefit of just one dose, and that the majority of risk of myocarditis comes with the second dose, critics have suggested a variety of different plans that would mitigate the risks to adolescents. Pegden, along with multiple coauthors, including an epidemiologist, two cardiologists, and a pediatrician, also wrote a separate essay critiquing the CDC’s “all or nothing” approach, listing several alternatives. Monica Gandhi, an infectious disease physician at UCSF, has suggested a variety of options as well. These include adolescents, or specifically young males, getting just one dose; administering the second dose later in time, since spreading out the doses may reduce the likelihood of a serious reaction; recommending only high-risk young people  get vaccinated; and for any adolescents who have immunity from prior infection, either just one dose or no vaccine at all, at least for the foreseeable future, since prior infection confers strong immunity.

Despite the UK study, fewer than two weeks after it was published, Walensky said “data from the UK show that one shot is really not working as well to stave off, especially, the Delta variant, and you really do need that second shot.” Two shots do offer more protection than one, and it’s not clear yet whether the protection from one dose may wane faster or not be sufficiently protective at some later date. But the CDC’s singular focus on every individual in American getting two doses, including those at a markedly higher risk after the second dose, such as young males, seems unnecessarily and perhaps harmfully myopic.

Further to this point, a slide in the committee meeting recommended that even if someone gets myocarditis following the first dose of the mRNA vaccine, if their heart recovers they should still consider getting a second dose. While some policy professionals were pleased with this advice, numerous cardiologists and other medical professionals condemned it. Venk Murthy, a cardiologist at the University of Michigan, commented: “In essentially no circumstances should a patient with myocarditis soon after first mRNA vax dose get a second dose, even if the heart recovers. The CDC got this wrong.” Physicians at three different major university hospitals in New York and California, who were not authorized to speak publicly, each told me this advice was “insane.”

The medical establishment has also fallen in line behind the CDC to back its questionable messaging. In a remarkable show of uniformity, a joint statement, cosigned by the heads of the CDC, the American Academy of Pediatrics, the American Heart Association, the American Medical Association, the American Nurses Association, the American Hospital Association, and 11 other national medical organizations, was released in reaction to the advisory committee meeting. It reads, in part:

Today, the CDC Advisory Committee on Immunization Practices (ACIP) met to discuss the latest data on reports of mild cases of inflammation of the heart muscle and surrounding tissue called myocarditis and pericarditis following Covid-19 vaccination among younger people.

The facts are clear: We know that myocarditis and pericarditis are much more common if you get Covid-19, and the risks to the heart from Covid-19 infection can be more severe.

We recommend getting vaccinated right away if you haven’t yet.

Several cardiologists and a pediatric immunologist I spoke with said there is no clear or definitive data they are aware of that myocarditis stemming from Covid-19 is likely to be more severe or common than it is from vaccination, particularly for healthy young people. Multiple messages to the CDC asking for the underlying data that this statement is based on went unreturned. One data point that would seem to call the claim into question is a CDC study that found the median hospital stay for a 12- to 17-year-old Covid-19 patient was 2.4 days. This is comparable to or below the median and average hospital stays in two studies on post-vaccination myocarditis that were referenced in the committee meeting.

The CDC has projected a binary assuredness about the risk-reward calculus for young people, and in particular young males, yet evidence suggests much of the data is ambiguous at best, and contradictory at worst, to the CDC’s public messaging. By not acknowledging nuance and uncertainties, the CDC makes it harder, not easier, for Americans to make informed choices. And it makes it harder, not easier, for Americans to trust the authorities. This communication style only serves to feed anti-vaxxers and the conspiracy-minded who seize upon incongruities or exaggerated claims. By all accounts the vaccines are miraculous. But as Shakespeare warned, we don’t need to perfume the violet.