Put together, he said, stricter rules “make it not as easy to get an exemption” and “make it a little bit clearer why these school entry requirements are important.” According to the JAMA Pediatrics paper, that is exactly what appears to be happening, with more families ultimately agreeing to proceed with vaccination.
From Coverage Slippage to Outbreaks
The United States is already facing sustained measles transmission across dozens of states. Declines in kindergarten coverage for measles, mumps, and rubella (MMR) and other routine vaccines can be the difference between isolated cases and explosive outbreaks, Conway warned.
“When people think about immunization coverage, there's a couple sort of, I wouldn't say magical numbers, but important numbers that we look at,” he said. “Typically when you introduce a new vaccine or as you're getting rolling with a new program, you try to achieve about an 80% immunization coverage rate ultimately with the goal of at least getting up to 90% or higher if possible.”
The gap between 90% and 80% coverage is not just 10 percentage points; it represents “a 100% increase in the number of vulnerable people in your community,” he said. “When you have 90% of the population immunized, that means only one in 10 people are susceptible… When you go down to 80%, it's only one in five people are suddenly vulnerable to the disease.”
He illustrated the difference with a simple scenario. “Somebody walks into a room with 20 people… if only two of them are… not been vaccinated, the odds are pretty small that that person with the illness is going to come into contact with that person,” he said. “Same scenario… instead it's one in five people are not immunized. Now you got four people out of 20 who are vulnerable… and it's pretty likely that they're going to come into contact with one of those people.”
“As we predicted and hoped would happen,” he added, “we saw with this paper that you reference that we in fact do have many more people then agreeing to proceed with getting vaccinated in the states where they've been able to remove these non-medical exemptions.” Those averages also mask local clustering.
“Rarely are these things equally distributed across the state,” Conway said. “There's going to be some school systems or some communities or neighborhoods where you may see places that we have in Wisconsin here where some areas of the state, only 50 or 60% of the kids are vaccinated against some of these diseases. So you have these pockets of vulnerability.”
“All it takes then is one person with one of these highly contagious diseases like measles showing up and getting into one of those communities and boom, you've got an outbreak happening,” he said. Diseases like measles and mumps have long incubation periods and people can be contagious before symptoms. “Once an outbreak gets started, it's really hard to shut it down,” Conway said, because of presymptomatic transmission and the challenge of retracing exposures over weeks.
Talking With Families: “The Norm Is To Be Vaccinated”
Conway pushed back on the idea that vaccine skepticism is now mainstream,“The perception is that it's more mainstream, but in fact it actually still does represent the minority and actually still does represent a fringe opinion,” he said. “If I'm talking about… the fact that… we're worried about the fact that we're getting… just below 90% immunization coverage in many areas of the country. That means that 9 out of 10 families actually do believe that vaccines are really important.”
“What you're seeing is that the perception is different because the hesitant families and the hesitant people are very, very loud, especially on social media,” he said. “There's this perception that it's more mainstream when in fact the behavior is actually still very, very much a fringe behavior.”
He believes clinicians and school nurses need to be explicit about this, “One of the things that clinicians and school nurses and others need to do is do a better job of talking about that it is the norm to be vaccinated, that most families do decide to vaccinate,” Conway said. “Most families decide that they do want to protect their kid from diseases that could disable or kill them.”
“These are not benign diseases. We don't immunize for these just for fun,” he added. “I guarantee you any kid that has ever had one of these diseases, if you ask them… would you have wanted that prevented, 100% of them are going to tell you absolutely they would do anything they possibly could did not have had that particular disease.”
He urged clinicians to emphasize both individual and community protection, especially for people who cannot be vaccinated or may not respond because of immune-compromising conditions or medications. “They do depend on the rest of the community, the rest of society being protected so that they aren't at risk of being exposed to these diseases,” he said.
Conway also distinguished between hesitancy and hardline opposition, “We've discovered that hesitancy is not by any means the same as anti-vaccination activities or what are called anti-vaxxers. That's even a smaller group of people that are completely… opposed to vaccines,” he said. “Really, it's a larger group of people that are now more comfortable that they have questions, they're hesitant, they want answers to their questions.”
“I think we all need to do a better job of making sure that they're getting reliable answers… and that we're encouraging them to talk to their own providers who they hopefully have a relationship with and have trust,” Conway said.
Policy Backlash: Risk of “Outbreaks Waiting To Happen”
Several states have recently debated weakening school vaccine mandates or removing them altogether. Conway warned that such policy shifts risk taking communities “back to a different era.”
“I think they're really potentially risking taking us back to a different era where… these diseases circulated more widely, where people had to be put into isolation and quarantine… sometimes for long periods of time,” he said. “They're on the risk of… potentially during larger outbreaks, getting to the point of needing to actually close schools for periods of time.”
He noted that loosening requirements also undermines basic situational awareness, “If you don't have a school entry requirement, there's no way that then the school nurses can even collect data and even know how many people are or aren't vaccinated within a particular school,” Conway said. “As soon as you have a couple of cases… you have no idea whether you're sitting in a place where you've got 90% of people immunized or whether you've got 40% of people immunized.” Without that data, he said, schools may have to “assume the worst anytime there's a couple of cases” and “likely move into a place where they close those schools or have to do the things that are more drastic.”
Bottom Line: Vaccines Are Safe, Effective, and Held to a Higher Standard
As states weigh vaccine policies, Conway believes the core message for families should remain simple, “I just think people need to remember that vaccines are safe and effective. Those are really the two things you care about with any pharmaceutical product. Are they safe and do they work to do what they're designed to do?” he said.
“Vaccines are and always have been held to a much higher standard than drugs,” he added, pointing to larger trial populations and longer development timelines. “Vaccines are studied in 10s of thousands, if not hundreds of thousands of people… typically vaccines take somewhere between 3 and 10 years of development.”
“If we do get over 90% immunization coverage in most areas… that's when you start talking about actually being able to eradicate diseases,” he said, citing smallpox, one type of polio, and prior progress toward measles elimination.
“Vaccines are safe, vaccines are effective, Vaccines are really important, both for individual health and for community health,” Conway concluded. “If we keep reminding people of that and keep directing them to ask their questions to trusted medical people within their communities, hopefully we'll get back to a place of trust… that'll hopefully get these outbreaks that we've been living through to settle down as soon as possible.”
Reference
Bald A, Gold S, Yang YT. State Repeal of Nonmedical Vaccine Exemptions and Kindergarten Vaccination Rates. JAMA Pediatr. Published online October 27, 2025. Accessed Novermber 17, 2025. doi:10.1001/jamapediatrics.2025.4185
