Our venerable local public radio station, WNYC, has published extensive data online about vaccination rates in NYC public schools.

The good news is that the average vaccination rate is 98%. The World Health Organization estimates that "herd immunity" -- the rate at which enough people are vaccinated to contain outbreaks even if a few people aren't immunized -- is between 83% and 94%. Still, 163 NYC public schools are near that cutoff, and 14 are below it.

Most public schools safely enjoy herd immunity, but we must bring the others in line and curb anti-vaccination trends. City and state policymakers need to decisively ensure parents really meet the criteria for the religious exemption. After all, parental resistance to vaccinations led to dangerous outbreaks of measles and whooping cough nationally.

In my view, too many children in NYC public schools -- 1,733, as per WNYC -- have received "religious exemptions" to vaccines under state law. But most major religions have not publicly prohibited congregants from immunizations. So, some parents may be faking the religious exemption because of confusion and fear about the risks of vaccines. They should not be permitted to endanger public health in the guise of sincere religious belief.

In addition, 17,498 NYC students are attending school with incomplete vaccinations. WNYC's data don't explain why that is, but since these kids presumably don't have exemptions, their parents are probably not objecting to vaccines on principle. More likely, the students have chaotic home lives, patchy health insurance or logistical barriers to getting the shots. This problem, however, has a simpler policy fix: Offer the shots in school. The city already offers flu shots that way -- a convenient alternative to a pediatrician appointment.

Vaccination figures like these prompt a lot of talk among New Yorkers about the need for more education about immunization. And many unfortunately enjoy making fun of the beliefs of parents opposing vaccination -- including the debunked link to autism.

But tightening the religious exemption and providing vaccinations at schools would really help keep our kids safe from what are clearly preventable diseases.

Liza Featherstone lives and writes in Clinton Hill.