Longtime allies of Robert F. Kennedy Jr., the nation’s health secretary, have launched a new effort to repeal laws that for decades have required children to be vaccinated against measles, polio and other diseases before they enter day care or kindergarten.

A newly formed coalition of vaccine activists is targeting laws that are considered the linchpin of protection from deadly diseases. States have long mandated childhood immunizations before children can start day care or school, though some exemptions are available.

…, a new umbrella group of at least 15 nonprofit organizations advocating an end to state laws that codify what they call medical mandates, which largely pertain to vaccines.

…Yet one potent guardrail against weakening immunization mandates has emerged. A number of polls show that voters would penalize lawmakers who favor eliminating school requirements. In one recent poll, conducted by The Wall Street Journal, voters gave Democrats a 9 percent advantage over Republicans when asked which party is best suited to handle vaccine policy.

Two polls commissioned by vaccine backers and conducted by Republican-leaning firms found that voters in Florida and Tennessee would not support lawmakers who want to end school-vaccine mandates. One poll by Fabrizio Ward, a firm that President Trump relies on, found that swing voters in tight congressional races would strip about 20 percentage points from a Republican candidate who was critical of vaccines.

“Vaccine skepticism is bad politics,” the Fabrizio Ward memo said.

Vaccine backers are still concerned about proposals in New Hampshire, Iowa, Idaho, Georgia and potentially other states that could end or sharply limit vaccine requirements for school entry.

“Prior to vaccines, one in five kids didn’t make it to their fifth birthday," said Jennifer Herricks, advocacy director for American Families for Vaccines, a nonprofit that receives some of its funding from vaccine makers. “Having these policies in place has really served to protect kids at the time when they are the most vulnerable to these diseases.”

The committee that sets national vaccine recommendations voted to change policies surrounding two major childhood inoculations after gathering last week for two days of contentious and chaotic meetings.

The 12 members, who were recently handpicked by controversial Health and Human Services Secretary Robert F. Kennedy Jr., also debated overturning decades of established practice around hepatitis B shots for newborns, though they ultimately tabled that vote.

The other two shots in play were the measles, mumps, rubella and varicella (chickenpox) combination vaccine, also known as MMRV, and this year’s COVID 19 booster.

By the end of the week, the Advisory Committee on Immunization Practices, also known as ACIP, voted to no longer recommend the MMRV combination vaccine for kids under 4 years old, rendering it largely inaccessible for that age group.

The committee also voted to shift the COVID 19 booster recommendation to “shared clinical decision making” for all people over 6 months old — regardless of age or risk level — meaning that before getting the shot, individuals will need to talk through the pros and cons with a health care provider, which includes pharmacists.

Through this departure, the committee largely preserved access and insurance coverage, while also raising doubts about the effectiveness and safety of the vaccine, at times citing debunked theories.

“There is just widespread confusion about, ‘What should I do as a parent? Who should I listen to?’” said Northe Saunders, executive director of the pro-vaccine advocacy organization American Families for Vaccines, formerly called SAFE Communities Coalition.

“American parents and American providers don’t actually know what the best recommendations are anymore,” he added, “and so that is going to lead to more hesitancy, because there’s uncertainty about what the right thing to do is, and that’s going to lead to declining immunization rates.”