15-04-2025
RFK Jr. claims 'leaky' measles vaccine wanes over time. Scientists say he's wrong.
Health and Human Services Secretary Robert F. Kennedy Jr. said the measles vaccine is "leaky" because its effectiveness wanes over time, something medical experts dispute.
Kennedy, a vaccine skeptic who now oversees the nation's federal health agencies, said the Centers for Disease Control and Prevention is doing a "very good job" of controlling the measles outbreak that has infected more than 700 Americans in 25 states as of April 10.
But Kennedy suggested the vaccine effectiveness wanes at a rate of nearly 5% a year – an assertion not backed by scientists.
"People get measles because they don't vaccinate," Kennedy said Tuesday during a press conference. "They get measles because the vaccine wanes. The vaccines wane about 4.8% per year ... So, you know, it's a leaky vaccine, and that problem is always going to be around."
Kennedy's remarks came during a press event Tuesday with Indiana Gov. Mike Braun and Centers for Medicare & Medicaid Services Administrator Mehmet Oz. The event, titled Make Indiana Healthy Again, touted steps the state was taking to improve health.
During a question and answer session with reporters, Kennedy said the doctors need to know how to treat measles, including its attacks on the lungs and body. Measles does not have any Food and Drug Administration-approved treatments, just the vaccine to prevent the disease.
"We can't rely simply on the vaccine," Kennedy said. "We also have to know how to treat measles."
In case you missed: RFK Jr., West Virginia's governor and why you shouldn't comment on someone's weight
Scientists disputed Kennedy's claim that the measles vaccine's effectiveness wanes over time.
"He's dead wrong," said Dr. Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia. "The measles vaccine protects you for the rest of your life. The notion that it's a leaky vaccine is dead wrong."
Offit said people who received one dose of the measles vaccine between 1968 and 1989 or two doses of the vaccine since then have lifelong immunity to the highly-infectious disease. He said the vaccine stimulates memory cells, which confer lifelong immunity.
Measles was eliminated in the U.S. by 2000 but has resurfaced with periodic outbreaks, mostly among people who are not vaccinated.
In the current outbreak, 97% of measles cases occurred in unvaccinated patients or those whose vaccination status is unknown, according to the CDC.
Did you see? What experts need you to know about the MMR vaccine
The CDC confirmed 712 cases as of Friday but Offit said there are likely far more cases because the disease spreads rapidly among unvaccinated populations. The current outbreak has spread rapidly in a Mennonite community in Texas, and people within the community might be reluctant to seek medical help, Offit said.
"I've had more than one public health official, including people on the ground, who said this could be between 3,000 and 5,000 cases," Offit said. "This is the worst measles epidemic we've had in 30 years."
This article originally appeared on USA TODAY: RFK Jr. claims measles vaccine is leaky. Experts disagree.
