Cammi Norwood's son Mason was jumping with joy at the thought of starting public school next year in Palmetto, Florida. The four-year-old, who was diagnosed with Stage 4 kidney disease at birth, has spent two healthy years without any hospital visits, and is eager to be in class with friends, Ms Norwood said.

But the 32-year-old mother is beginning to reconsider sending her immunocompromised son to school, after Florida's surgeon general last week announced he would try to end vaccine mandates in the state, including those for school children.

It's just scary, Ms Norwood said. If these kids aren't vaccinated … he can get very, very sick if someone were to come in with the measles.

Medical experts and some parents worry the surgeon general's move will threaten the health of vulnerable children like Mason, setting the stage for a new era of infectious disease, driven by lower vaccine rates. We'll end up having pockets of outbreaks of different types of infectious diseases, Florida's former surgeon general, Scott Rivkees, told the BBC.

If Florida goes ahead, it would be one of the first states to officially do away with childhood vaccination mandates, which have long been a fixture in parents' back-to-school plans. In April, Idaho's governor signed a law loosening vaccine requirements.

These moves coincide with Health Secretary Robert F. Kennedy Jr.'s mission to reshape US vaccine policy during a time when the Centers for Disease Control and Prevention (CDC) faces its own internal challenges.

Florida Surgeon General Joseph Ladapo, who announced this effort, compared existing mandates to slavery. His plan is backed by Republican Governor Ron DeSantis, but leading medical organizations, including the American Academy of Pediatrics, oppose it.

Despite reassurances from some parents who welcome the relaxed laws, a significant portion of the population remains deeply concerned about the health implications of such changes. A survey shows about 80% of parents in Florida want vaccine requirements for public schools, indicating strong support for maintaining existing health protocols.

Moreover, there are growing fears that as vaccination rates dip, previously controlled infectious diseases may once again pose severe threats to the public, particularly to immunocompromised individuals like Mason. With diseases such as pertussis and measles making a return, experts warn that the aftermath of lifting vaccine mandates could lead to overcrowded hospitals and a public health crisis.