Vaccination Rates Teetering on a ‘Knife’s Edge’ with Dramatic Consequences
As U.S. childhood vaccination rates sway on a “knife’s edge,” new 25-year projections reveal how slight changes in national immunization could improve—or drastically reverse—the prevalence of measles, polio, rubella, and diphtheria. Measles, rubella, polio, and diphtheria—once everywhere, causing chaos and fear—have been pretty much kicked out of the U.S. for ages. Generations have hardly seen these diseases thanks to high vaccination rates and intense surveillance efforts that have kept major outbreaks at bay.
But hold up! In the midst of a massive multistate measles outbreak with hundreds of cases popping up, a recent study published in JAMA predicts that even a tiny dip in the current U.S. childhood vaccination rates could undo all the progress made, bringing back these nasty illnesses within 25 years. And get this—a little increase in rates could squash all four of them for good.
The Centers for Disease Control and Prevention and the World Health Organization declare a disease eliminated when there’s no continuous transmission in a specific area for 12 months or more. The U.S. waved goodbye to measles in 2000, polio was out of North and South America by 1994, rubella got the boot in 2004, and diphtheria was on its way out in the 1940s. These are big deals, according to study co-author Nathan Lo, a physician-scientist at Stanford University. They’re diseases that the U.S. managed to kick to the curb through vaccination.
### The Risk of Slipping Back Into Old Habits
The study, led by Mathew Kiang, an assistant professor of epidemiology and population health at Stanford University, ran different scenarios of childhood vaccination rates over 25 years to see if these diseases would make a comeback. Measles, being super contagious, was the most vulnerable to changes in vaccination coverage. A 5 percent drop could mean a whopping 5.7 million measles cases in 25 years, while a 5 percent increase would only bring about 5,800 cases. Polio and rubella would need bigger drops in vaccination rates (around 30 to 40 percent) to be at risk of returning.
But wait, there’s more! Diphtheria might have lower projected cases, but it’s no joke. It has a high fatality rate and can take you down real quick. Lo points out that “Patients with diphtheria get symptomatic and within a day or two can die.” Yikes! Childhood immunization numbers have been dropping slowly but surely recently due to various reasons, like missed appointments during the COVID pandemic and growing public resistance to vaccines. With trust in vaccination declining and funding cuts to international vaccine programs, the risk of these diseases making a comeback is on the rise.
