ProPublica is an independent nonprofit news organization focused on exposing abuses of power. Register to get our top stories delivered right when they’re released. Prior to vaccines, death and disability haunted children. Shots transformed once-common infections into ailments doctors now only encounter in textbooks. But when immunization rates fall, past plagues can resurge, as measles has in U.S. communities where parents opted against vaccinating their kids. Picture the consequences if even those seeking shots couldn’t obtain them. Health Secretary Robert F. Kennedy Jr., founder of an anti-vaccination group, is eyeing reforms that might lead the few companies producing most U.S. childhood vaccines to halt sales here. In the past year, he has been reshaping a government that once strongly promoted the life-saving advantages of vaccines into one that now doubts their safety both domestically and globally. Soon after Kennedy’s nomination, speculation arose about how he might revamp America’s vaccination framework. Two researchers from Stanford University investigated how many people would be affected if vaccination rates declined or vaccines became completely unavailable for four notorious diseases: polio, measles, rubella, and diphtheria. Outbreaks frequently begin when an American contracts one of these diseases overseas and brings it back home. Epidemiologists Mathew Kiang and Nathan Lo, an infectious diseases physician, created a model simulating the spread of the four contagions from ill travelers, factoring in each state’s vaccination rates. With a significant portion of the population vaccinated, some infections wouldn’t establish a foothold immediately. However, over time, with more babies born unvaccinated, a greater proportion of the population would become susceptible. The professors conducted thousands of simulations for each disease, generating a variety of potential outcomes. From there, they calculated the average number of deaths and disabilities over a 25-year period. Their model indicates that at current vaccination rates, the nation is already on the verge of a measles case explosion — one that could be virtually eliminated with just a 5% increase in vaccination.
