A new vaccine advisory panel hand-picked by Health and Human Services Secretary Robert F. Kennedy Jr. has voted to change its MMRV vaccine recommendation for young kids.

The CDC's Advisory Committee on Immunization Practices voted Thursday to no longer recommend the MMRV vaccine -- which protects against measles, mumps, rubella and varicella (chickenpox) -- for children younger than four. Instead, the panel recommends that kids in that age group should get the MMR vaccine and the chickenpox vaccine separately.

The vote was eight to three, and one committee member abstained. The recommendation comes as measles cases hit their highest point this year since the U.S. declared the virus was eliminated in 2000.

The panel also voted to keep the MMRV vaccine covered by the federal Vaccines for Children program for kids as young as 12 months. That means the parents of children eligible for the program will still be able to choose between the single MMRV vaccine or two separate immunizations.

But the Children's Health Insurance Program and Medicaid will both be affected by the new recommendation and may not cover the MMRV shots anymore, NPR reports.

The committee's recommendations won't become official CDC guidance without approval from the agency's director. CDC directors typically accept the panel's recommendations.

"HHS will examine all insurance coverage implications following today's ACIP recommendation, prior to a final decision on adoption by the Acting Director," a Health and Human Services spokesperson said in a statement. "A recommendation from ACIP becomes part of the CDC immunization schedule if it is adopted by the CDC director."

In the lead-up to the vote, the panelists discussed rare cases of feverish seizures in young kids who received the MMRV vaccine. Committee member Dr. Cody Meissner said these seizures may be "a very frightening experience" for parents, but experts say they don't impact brain function or cause problems in school, the Associated Press reports.

Some lawmakers are now expressing concern about the change. Senator Elizabeth Warren, a Democrat, said that it could now be harder for kids to get vaccinated for measles and other viruses.

"Measles cases hit record highs with RFK Jr. in charge," she wrote on X. "Now, his hand-picked vaccine panel just voted to make it harder for little babies to get vaccinated for measles and other diseases. How does that keep our kids safe?"

The panel will meet again on Friday to vote on recommending Hepatitis B vaccines for newborns and Covid-19 vaccines for all ages. The panel currently has 12 members who were all hand-picked by vaccine-skeptic Kennedy, after he removed 17 existing members earlier this year. Several members have espoused anti-vaccine views, along with Kennedy himself, the AP reports.

CDC Director Susan Monarez was also fired from her post in August, less than one month into her tenure. Monarez told lawmakers on Wednesday that she was fired after Kennedy asked her to preemptively approve vaccine recommendation changes and fire long-time officials overseeing vaccine policy.

"He said if I was unwilling to do both, I should resign," Monarez testified.

"I would not commit to that, and I believe it is the true reason I was fired," she added.

RFK Jr's new vaccine panel recommends against MMRV vaccine for kids under 4