For two decades, measles was largely a rarity in the United States.

Now the numbers look very different.

According to data from the Centers for Disease Control and Prevention, the United States recorded approximately 4,235 measles cases during the entire 20-year period from 2005 through 2024.

In 2025 and the first nine months of 2026 alone, the United States recorded 5,948 confirmed cases.

That means fewer than two years have produced roughly 1,700 more measles cases than the previous 20 years combined.

And much of that explosion has occurred while Robert F. Kennedy Jr. has been running the nation's Department of Health and Human Services.

KENNEDY TAKES OVER HHS

Robert F. Kennedy Jr. was sworn in as Secretary of Health and Human Services on February 13, 2025.

That put Kennedy in charge of a sprawling department that includes the Centers for Disease Control and Prevention, the Food and Drug Administration and the National Institutes of Health.

Kennedy did not create America's declining vaccination rates.

The trend began years before he entered government, and the major Texas measles outbreak of 2025 had already begun before he was sworn into office.

Those facts matter.

But what happened after Kennedy took office is equally difficult to ignore.

The United States finished 2025 with 2,289 confirmed measles cases.

By September 24, 2026, another 3,659 cases had already been reported.

Combined, that's 5,948 confirmed cases during 2025 and 2026.

Because Kennedy did not take office until February 13, some of the 2025 cases occurred before his tenure began.

But the scale of the resurgence is unmistakable.

TWENTY YEARS: ABOUT 4,235 CASES

Consider what measles looked like before the current resurgence.

From 2005 through 2024, approximately 4,235 cases were reported in the United States.

And that total includes two unusually large outbreak years.

In 2014, the country recorded 667 cases.

In 2019, another major outbreak pushed the annual total to 1,274.

Those two years alone accounted for nearly half of all measles cases during the entire 20-year period.

Most years were dramatically quieter.

There were 66 cases in 2005.

There were 55 in 2006.

There were 43 in 2007.

There were just 13 in 2020.

Even in 2024, immediately before Kennedy became HHS secretary, the United States recorded 285 cases.

Then came 2025.

2,289 cases.

Then 2026.

3,659 cases — and the year isn't over.

MEASLES WAS ELIMINATED IN AMERICA

This isn't a disease Americans simply learned to tolerate.

The United States declared measles eliminated in 2000.

"Eliminated" doesn't mean that nobody ever contracts measles.

Travelers can become infected overseas and bring the virus into the United States.

Elimination means the disease is no longer continuously spreading within the country.

For more than two decades, America's vaccination program and rapid public-health response generally prevented imported cases from turning into sustained nationwide transmission.

The measles vaccine was central to that success.

According to the CDC, the MMR vaccine is safe and highly effective.

Two doses are about 97 percent effective at preventing measles.

But measles is extraordinarily contagious.

When vaccination rates decline, the virus finds opportunities to spread.

VACCINATION RATES ARE FALLING

That's exactly what has been happening.

CDC figures show MMR vaccination coverage among American kindergarteners has fallen from 95.2 percent during the 2019-2020 school year to 92.4 percent during the 2025-2026 school year.

That may sound like a relatively small decline.

For measles, it isn't.

Because the disease spreads so easily, public-health officials generally aim for vaccination coverage above 95 percent to maintain strong community protection.

The CDC estimates that approximately 280,000 kindergarteners were at risk during the 2025-2026 school year.

And national averages can conceal much larger vulnerabilities.

Some individual communities have vaccination rates substantially below the national figure.

When measles enters one of those communities, an imported case can quickly become an outbreak.

95 PERCENT OF 2026 CASES ARE CONNECTED TO OUTBREAKS

The CDC's 2026 numbers illustrate the problem.

As of September 24, there had been 3,659 confirmed measles cases in the United States.

Forty new outbreaks had been reported.

And an extraordinary 95 percent of confirmed cases were associated with outbreaks.

That is not simply a collection of unrelated travelers returning home sick.

It represents sustained transmission within vulnerable communities after the virus arrives.

THE RFK QUESTION

Kennedy's role in this story requires some precision.

It would be inaccurate to say that Kennedy personally caused America's measles resurgence.

Vaccination coverage had been declining before he became HHS secretary.

International measles activity creates opportunities for infected travelers to bring the disease into the country.

And the Texas outbreak had already started before Kennedy took office.

Kennedy has also publicly acknowledged that vaccination protects against measles.

In March 2025, while responding to the Texas outbreak, Kennedy wrote that the MMR vaccine was "crucial" to preventing potentially deadly disease and said vaccines protect both individual children and their communities.

But Kennedy has spent years as one of America's most prominent vaccine skeptics.

That history makes what happens under his leadership of the country's most powerful public-health agency especially consequential.

HHS isn't merely observing the measles resurgence.

It oversees the CDC.

It helps establish national vaccination policy.

It communicates with millions of Americans about vaccine safety.

And its leadership can either strengthen or weaken public confidence in vaccination.

THE NUMBERS ARE NOW IMPOSSIBLE TO IGNORE

For twenty years — 2005 through 2024 — America recorded roughly 4,235 measles cases.

Then:

2025: 2,289.

2026 through September 24: 3,659.

Combined: 5,948.

In less than two years, America has recorded roughly 40 percent more measles cases than it did during the entire preceding 20-year period.

And 2026 isn't finished.

This doesn't prove that one cabinet secretary caused a public-health crisis.

It does establish something much harder to dispute:

The United States is experiencing its most serious measles resurgence in decades while vaccination coverage is declining.

Robert F. Kennedy Jr. now leads the federal department responsible for confronting it.

The question isn't whether he created every condition that allowed measles to return.

He didn't.

The question is what the nation's health department will do now that it has.