Amid a measles outbreak that has seen U.S. cases for the year so far surge past the total tracked in 2024, Health Secretary Robert F. Kennedy Jr. has responded, in part, by suggesting alternatives to vaccination, including treating with vitamin A.

"We're providing vitamin A," Kennedy told Sean Hannity in an interview that aired on Fox News in mid-March. "There are many studies, some showing 87% of effectiveness of vitamin A against serious disease and death."

Cases related to a Texas outbreak dating to January now surpass 327, including one confirmed death, largely in unvaccinated people. In Western Pennsylvania, the Erie County Department of Health on Tuesday announced two cases of measles on its Facebook page, both related to international travel. The first case in Pennsylvania of the year, also related to international travel, was confirmed in Montgomery County outside Philadelphia earlier this month.

The last known case in Allegheny County was in 2019, per the Allegheny County Health Department.

The assertion by Kennedy, a key Trump administration figure overseeing numerous federal agencies, that vitamin A successfully treats measles symptoms is based on real research but is taken out of context, say infectious disease experts.

While studies have shown vitamin A to be effective at treating measles symptoms, many of those trials were done on children with vitamin A deficiencies in low-resource countries.

That context is key, said Amesh Adalja, a Pittsburgh-based physician and senior scholar with Johns Hopkins Center for Health Security. "Vitamin A deficiency is not an issue in Texas or New Mexico. He's completely shearing vitamin A away from the context from which it applies. This is not applicable to the current outbreak."

Protecting against measles

Kennedy, in an opinion piece for Fox News posted March 2, pointed to the effectiveness of the measles, mumps and rubella (MMR) vaccine since its implementation decades ago.

He also noted that CDC guidelines for measles have been updated to include "supporting administration of vitamin A under the supervision of a physician for those with mild, moderate, and severe infection."

The Texas Department of State Health Services reported 327 measles cases as of March 25; while nearby states New Mexico and Oklahoma have reported 43 and seven confirmed cases, respectively. The measles outbreak is Texas's worst in 30 years, and pushed the U.S. past the 2024 measles case count, which was 285, per the Centers for Disease Control and Prevention.

"Vitamin A does not diminish your chance of acquiring a measles infection," said Donald Karcher, president of the College of American Pathologists and a professor at the George Washington University Medical Center in D.C. "We certainly do not recommend anyone to be self-medicating with vitamin A."

The MMR vaccine remains the best true preventive measure against measles, officials said. It has been shown to be 97% effective at preventing the highly contagious disease as well as associated severe complications. In use for about five decades, the vaccine has been given to millions and data shows severe side effects are rare.

Scientific studies — mostly conducted in low-income countries with a higher measles burden — do show that vitamin A can reduce recovery time from pneumonia, diarrhea and time in the hospital. A majority of the randomized controlled trials reviewed in a 2010 review study were from the World Health Organization treating children with vitamin A deficiencies.

When reviewers looked at vitamin A on the whole to treat measles burden, it did not significantly provide benefit. Only at the high doses of 200,000 International Units for children older than 1 year and 100,000 IUs for infants did researchers see this benefit.

There's also a risk of overdosing on vitamin A. It's a fat- soluble vitamin, so the body does not clear it through urine in the same way as water-soluble vitamins. Instead, excess is stored in the body and can lead to nausea, vertigo, blurred vision and vertigo, according to the Mayo Clinic.

Vitamin A supplements should not be taken while pregnant, or if an individual is taking anticoagulants, retinoids or drugs that in high doses can damage the liver.

"The idea of using vitamin A has come from more resource-limited countries," said Ben Bradley, assistant professor in pathology at the University of Utah, in a March 13 measles webinar. Dr. Bradley is also the medical director of virology at ARUP Laboratories, a nonprofit lab with the University of Utah. "We have to advise a lot of caution here."

Kids in the MMR vaccine group saw between 85% and 98% protection against severe outcomes when given two doses.

Kennedy said in his media interviews that the measles death rate is "relatively small," and that those who die are people with comorbidities and who are malnourished.

Dr. Adalja disagreed with that assessment. "This is not the same demographic who died from influenza or COVID."

The 6-year-old girl who died from measles in Gaines County, Texas, seems to have been previously healthy with no underlying conditions. She was not vaccinated against measles.

Before development of the MMR vaccine, measles cases hospitalized about 48,000 Americans a year and killed 500, according to the CDC. By 1981, about a decade after the vaccine was released, measles cases dropped 80% compared to the year prior, per CDC.

In his interview with Hannity, Kennedy said that a measles infection provides lifelong immunity against the disease, whereas the MMR vaccine does not. He said MMR vaccine immunity wanes to the point that "older people are essentially unvaccinated."

Dr. Adalja disputed this.

"Even if there is numerical waning of antibody protection over time, when we look at measles outbreaks and who is getting infected, it's those who are unvaccinated," he said.

"This does not have clinical relevance. You have to actually look at the outbreak on the ground, and (in vaccinated people is) not where the infections are occurring."

Only two people who reported receiving both doses of the MMR vaccine also currently are counted in Texas's measles outbreak. The vaccination status of each and every case is not known.

Statistics indicate 75% of the Texas measles cases are minors, with 19% of current cases found in people over the age of 18.

"We also know that (measles) infection significantly weakens a person's immune system, which places them at very high risk for other potentially serious infections," said Tina Tan, a pediatrician and professor of pediatrics and infectious disease at Northwestern University Feinberg School of Medicine, during a March 20 measles webinar.

Consequences of dropping vaccine rates

The measles virus causes fever, fatigue, cough, runny nose and a characteristic rash. It can also lead to complications such as ear infections, pneumonia, blindness, brain swelling and death.

Measles is far more contagious than influenza, the common cold or COVID, with particles from an infected person capable of lingering in the air and infecting someone else for up to two hours.

"A person with measles can transmit the disease to as many as 18 other susceptible individuals, with transmission in a household setting of 90% or higher," said Dr. Tan.

When vaccine rates drop in a community, it's not a matter of if but when an outbreak will occur, said David Higgins, attending physician in the Child Health Clinic at Colorado University's Anschutz Medical Campus, specializing in vaccine hesitancy, in the March 20 webinar.

One school district in Gaines County, where much of the Texas measles outbreak is concentrated, has a vaccine exemption rate of 48%. The county overall vaccination rate is 82%, which is below the herd immunity threshold of 95%.

"We know that these outbreaks happen in local communities," Dr. Higgins said. "So even if a state has a rate that is at the goal, that might not mean that a local community is at that goal."

_____

© 2025 the Pittsburgh Post-Gazette. Visit www.post-gazette.com. Distributed by Tribune Content Agency, LLC.