Jewish camps across the country have adopted formalized vaccine policies in recent years requiring staff and campers to be immunized according to state requirements. This includes all camps under the auspices of the Union for Reform Judaism and the Conservative movement’s Ramah umbrella, as well as many independent and specialized camps.

Some state vaccination laws allow for personal or religious exemptions, which can get sticky. California, which experienced a widely publicized measles outbreak at Disneyland early last year, joined West Virginia and Mississippi as one of only three states that outlaw personal or religious vaccine exemptions after passing a contested bill last summer. The vaccination rate among children in California has already risen even though the new law does not go into effect until July 1.

Vaccines are generally accepted as a common-sense medical practice across most of the spectrum of religious affiliation in the Jewish community. However, some Orthodox communities have experienced outbreaks of preventable diseases, like whooping cough, in recent years.

In 2014, the prominent Orthodox Rabbi Shmuel Kamenetzky called vaccines a “hoax.” JTA found last year that a range of private Jewish day schools had low student vaccination rates due to the personal or religious exemption loopholes.

Cliff Nerwen, chair of the National Ramah Medical Committee, estimates that at least one family each year tries to send an unvaccinated camper to each of Ramah’s nine sleep away camps.

“I graciously tell them I respect their opinions, but in the light of the larger public health community, it’s a risk we’re not willing to take,” Nerwen said.

Paul Reichenbach, the Union of Reform Judaism’s director of camp and Israel programs, noted, “Of course there are parents out there that have chosen not to vaccinate their children, and I think they always assume that either their personal or their religious reasons for not vaccinating will be accepted.”

When the URJ camp system issued a formalized vaccine policy in 2008, “it came as a surprise to some people,” Reichenbach said.

Dr. Peter Lipson, an internal medicine specialist who practices in West Bloomfield, Michigan, and covers science and medicine for Forbes, noted that some children have legitimate medical reasons to skip a certain vaccine — and they depend on the immunity of the other campers around them even more.

As to whether or not parents should scrutinize camps that allow non-medical exemptions, Lipson said the issue is worth talking about.

“Because this is such a new question, I’m just starting to ask [it] myself,” he said. “Personal belief exemptions are a nightmare.”

Lipson pointed out that it can be tough for camps to hold their ground against parents on the vaccine issue because, while everyone has to go to school, they’re not required to attend summer camp.