An advisory committee overseen by Health and Human Services Secretary Robert F. Kennedy Jr.’s vaccine advisory board will meet Thursday to discuss the medical guidance of the hepatitis B vaccine, which is currently given at birth.

The Centers for Disease Control and Prevention is experiencing chaos unlike anything ever seen before. Meanwhile, there’s also growing concern in the medical community over changing vaccine guidelines and the cancellation of cutting-edge vaccine research.

The nation’s 19 million children under 5 are the only group not yet eligible for vaccination against the coronavirus. Many parents have been pushing for an expansion of shots to toddlers and preschoolers, especially as the omicron wave sent record numbers of youngsters to the hospital.

One year into Dr. Rochelle Walensky’s tenure as director, her bid to make the Centers for Disease Control and Prevention more agile is being challenged by political pressures, vocal scientists and the changing virus itself.

The findings released Tuesday are preliminary and have not been peer-reviewed — the gold standard in scientific research — but they line up with other early data about omicron's behavior, including that it seems to be more easily transmitted.