Hiltzik: CDC officials debunk RFK Jr. claims on vaccines

Here’s how one of the well-laid plans of Health and Human Services Secretary Robert F. Kennedy Jr. went blooey.

Earlier this month, Kennedy dismantled the all-important Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention, and remade it into the spearhead for his anti-vaccination campaigns.

The rejiggered committee met for the first time Wednesday. Unfortunately for Kennedy’s goals, the very first presentation it heard from CDC scientists involved the safety of the COVID-19 vaccine, particularly for pregnant women, infants and children.

CDC studies found “no increased risk” that the Moderna and Pfizer mRNA vaccines caused adverse effects during pregnancy, Sarah Meyer, director of the CDC’s Immunization Safety Office, said at the meeting, citing data from 28 analyses of 68,000 pregnant women. The data showed no increases in miscarriages, stillbirths, preterm births, major birth defects, neonatal ICU admissions, infant deaths, abnormal uterine bleeding or other pregnancy-related conditions.

In fact, the CDC found that “maternal vaccination is the best protection against COVID-19 for pregnant women and infants less than six months of age,” CDC immunologist Adam MacNeil told the panel. The COVID vaccines aren’t approved for infants younger than six months, so maternal immunization is their only protection.

That’s important because Kennedy, on May 17, removed the vaccines from the recommended list for pregnant women and children. “It’s common sense and it’s good science” to remove the recommendation, Kennedy said in a 58-second video posted on X.

“We’re now one step closer to realizing President Trump’s promise to make America healthy again,” Kennedy crowed, flanked by Marty Makary, the newly appointed commissioner of the Food and Drug Administration, and Jay Bhattacharya, the newly appointed director of the National Institutes of Health.

Neither body plays a role in issuing vaccine recommendations for the government. That’s the job of the CDC, which has been operating without a director, and which didn’t have a representative on the video.

Pediatric and obstetric organizations decried the decision, which ran counter to the findings of extensive research. “Clear benefits of maternal immunization versus COVID in terms of dramatic reductions in maternal mortality and protecting the newborn infant … has been detailed in the biomedical literature,” vaccinologist Peter Hotez told me by email.

I asked Kennedy through his agency’s public information team for comment on the CDC presentation, but received no reply.

On June 9, Kennedy fired all 17 members of ACIP of the immunization advisory committee and replaced them with eight handpicked members, a cadre that includes “antivaxxers, the antivax-adjacent, and the unqualified,” as veteran pseudoscience debunker David Gorski noted.

The COVID vaccines have been a leading target of anti-vaccine activists, including Kennedy, since they were introduced in 2021. They’ve been blamed for a host of purported health harms, most of which have been found by researchers to be largely imaginary.

The anti-vaccine camp maintains that the vaccines weren’t adequately studied before rolling them out to the general public and haven’t been sufficiently monitored for adverse effects since then.

The CDC officials’ presentation debunked almost all these claims. Indeed, Meyer said, the COVID-19 vaccines have been subjected to “the most extensive safety monitoring program in U.S. history.”

The CDC has investigated more than 65 possible adverse effects of the vaccine, Meyer said, including heart attacks, meningitis, spontaneous abortion, seizures and hospitalization.

Other than pain at the injection site, fainting and other transitory conditions common to most vaccines, it has found evidence for one condition — myocarditis, a heart inflammation seen especially in men aged 12 to 29.

That appears to be a short-term condition, with 83% of patients recovering within 90 days of onset, and more than 90% fully recovered within a year. No deaths or heart transplants are known to have occurred, the CDC data show. No confirmed cases were seen in children younger than 5.

The myocarditis rate among vaccine recipients aged between 6 months and 64 years appeared to spike in 2020-22, when it seemed to be related to the original vaccine and the original booster. After the booster was reformulated, the rate among those aged 12 to 39 fell to about one case per million doses in 2024-25 — half the rate found in the general population.

Despite the relative rarity of myocarditis, the condition has underpinned a campaign by anti-vaccine activists to take the vaccines off the market. Among them is Joseph Ladapo, the Florida surgeon general, who in 2022 advised males aged 18-39 not to get the COVID vaccine.

His advisory earned him a crisp upbraiding from the then-heads of the FDA and CDC, who informed him by letter that “the known and potential benefits of these vaccines clearly outweigh their known and potential risks…. Not only is there no evidence of increased risk of death following mRNA vaccines, but available data have shown quite the opposite: that being up to date on vaccinations saves lives compared to individuals who did not get vaccinated.”

And on Wednesday, just as the CDC team was telling ACIP that the myocarditis effect had ebbed to insignificance, the FDA announced that it was expanding the warning label on the mRNA vaccines to increase the caution about myocarditis — a change with the potential to undermine acceptance of the vaccines.

Overall, the rate of death seven days after mRNA vaccinations has been lower than the background rates among the general population for the most common causes of death — such as heart disease, cancer and stroke.

I’ve written before that Kennedy’s anti-science campaign against vaccination — or more properly, his science-free campaign — has set the stage for a public health crisis in the U.S. Videos posted on X citing nonexistent evidence is no substitute for medical judgments based on science. They won’t make America healthy, but will make Americans much sicker. Kennedy’s actions are potentially deadly, and the CDC has the data to prove it.