New kindergarten vaccine data has RFK Jr.'s stamp all over it

In an early but damning gauge of Robert F. Kennedy Jr.’s impact since his ascent to U.S. health secretary, a growing number of Americans are sending their kids off to kindergarten without crucial vaccines.

New data from the Centers for Disease Control and Prevention shows that rates of childhood vaccinations fell across the board for kindergarteners during the 2025-2026 school year. Some 280,000 littles had not completed their measles, mumps and rubella vaccine last year. That drop in coverage unsurprisingly came alongside a continued rise in vaccine exemptions.

Put another way, fewer American children are now protected from entirely preventable, life-altering and even life-threatening diseases like measles, polio and tetanus.

As we head into another school year, we should worry that the ongoing attacks on vaccines — now with the full-throated support of President Donald Trump, who last week called for the MMR shot to be broken into three separate vaccines — will mean even more kindergarteners walk through the front door vulnerable to highly infectious diseases.

The national trend has been underway for several years. But the potential damage from Trump’s health secretary, who devoted his first months in office to dismantling the U.S. vaccine infrastructure and sowing confusion over the safety and necessity of shots, is becoming evident.

A protracted measles outbreak since the start of 2025 has sickened nearly 5,000 people, hospitalized more than 400 and killed two children. In normal times, health authorities would be doing everything possible to reverse this alarming trend. Instead, under this administration, the MMR vaccination rate was stuck at around 92.5% last year, according to the CDC. That’s well below the 95% coverage needed for an entire community to be protected from the spread of disease.

Parents, concerned by headlines about very sick kids, have in the past been motivated to get their own children protected. That dynamic has played out in South Carolina, the epicenter of a large measles outbreak last year. Vaccination rates among kindergartners there has markedly improved, increasing to 93.4% in the 2025-2026 school year from 91.2% during the previous school year.

But in other parts of the country, the opposite is occurring. In Utah, just 87% of kindergarteners were up to date on their MMR vaccine last year; a decade ago, that number hovered near the 95% target for coverage. That low rate is kindling for preventable diseases, and Utah sure enough has become the latest epicenter of the measles outbreak, with nearly 520 people sickened this year alone.

The proliferation of laws that have made it easier to refuse routine childhood shots haven’t helped. During the 2025-2026 school year, vaccine exemptions, which hovered just over 2% in the years preceding the pandemic, increased to 4.2%. In nearly half of states, more than 5% of kindergarteners are now excused from at least one shot — and the number is higher than 10% in a handful of states, like Idaho and Arizona.

Kennedy’s supporters have a litany of excuses for the decline in vaccine coverage. They argue that the turn away from routine childhood vaccines began years before he came into government office and was magnified by the pandemic so couldn’t possibly be his fault. They point out that pockets of vaccine refusal include groups with deeply held religious beliefs that long predate his arrival in Washington. Moreover, they say Kennedy hasn’t taken away anyone’s vaccines, and that he is simply restoring "medical freedom" and parents’ rights.

Those arguments conveniently elide Kennedy’s anti-vaccine crusading before and during the pandemic. He notoriously spread vaccine misinformation on social media and through the nonprofit he founded, Children’s Health Defense, while trying to weaken state laws requiring childhood vaccines for school. And Kennedy directly targeted communities that later experienced disease outbreaks, stoking vaccine fears during a visit to an Amish community in Pennsylvania, for example, in 2021.

Once appointed health secretary, Kennedy immediately turned his focus to codifying his anti-vaccine ethos — and using the enormous megaphone granted by his position to sow further confusion over the safety and effectiveness of routine vaccines.

The messaging from health agencies has sharply shifted under his leadership. The CDC’s brief statement accompanying the latest kindergarten vaccine data is yet another example of the problem. The agency said it "continues to encourage parents to discuss vaccination options with their doctors."

That’s not a ringing endorsement of vaccination. It’s at best a vague suggestion that proven, effective vaccines happen to be available in case parents would like to have the option of safely protecting their children and their communities. This year’s kindergartners, and all the kids that come behind them, deserve so much better.

This column reflects the personal views of the author and does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners. Lisa Jarvis is a Bloomberg Opinion columnist covering biotech, healthcare and the pharmaceutical industry. Previously, she was executive editor of Chemical & Engineering News.