Childhood vaccination rates in the United States have been steadily declining since the COVID-19 pandemic, raising serious concerns among public health officials about potential outbreaks of preventable diseases. New research indicates this trend could lead to millions of preventable infections over the next 25 years if not reversed.
According to data from the CDC, the rate of kindergartners with complete vaccination records for measles, polio, whooping cough, and chickenpox has fallen from 95% pre-pandemic to under 93% currently. While this decrease might seem modest, it has created vulnerable pockets across the nation where students are no longer protected by herd immunity.
A comprehensive simulation study published in JAMA utilized state-level modeling to predict the consequences of various vaccination scenarios. The researchers found that at current vaccination rates, the U.S. could expect 851,300 measles cases, 190 rubella cases, 18 poliomyelitis cases, and 8 diphtheria cases over the next 25 years, resulting in approximately 2,550 deaths and 170,200 hospitalizations.
"The timing and critical threshold for returning to endemicity will differ substantially by disease, with measles likely to be the first to return to endemic levels and may occur even under current vaccination levels without improved vaccine coverage and public health response," the study authors warned.
COVID-19 Vaccine Hesitancy Spilling Over to Routine Childhood Immunizations
A separate study published in the American Journal of Public Health has identified a concerning link between COVID-19 vaccine hesitancy and declining rates of routine childhood immunizations. Researchers analyzed responses from nearly 20,000 parents of children under age 5, finding that children of parents who received at least one COVID-19 vaccine had significantly higher MMR vaccination rates (81%) compared to children of unvaccinated parents (61%).
"Our research suggests that COVID-19 vaccine hesitancy has fueled increasing MMR vaccine hesitancy, leaving children more vulnerable to highly contagious and life-threatening illnesses like measles," said Dr. Ben Rader, a computational epidemiologist with Boston Children's Hospital and researcher on the study.
The consequences of this trend are already becoming apparent. Last year, 16 measles outbreaks were reported across the country, compared to just four outbreaks in 2023, according to CDC data.
Geographic and Socioeconomic Disparities in Vaccination Coverage
The JAMA study revealed significant state-level variations in vaccination coverage and susceptibility to outbreaks. Current childhood vaccine coverage across U.S. states ranges from 88% to 96% for measles-mumps-rubella (MMR), 78% to 91% for diphtheria-tetanus-pertussis, and 90% to 97% for inactivated poliovirus.
Texas was identified as having the highest risk for measles outbreaks based on current vaccination trends. Additionally, several states have experienced particularly steep declines in kindergarten vaccination rates, with Alaska, Florida, Idaho, Minnesota, Montana, South Dakota, and Wisconsin all seeing at least 10% drops from 2023 to 2024.
The American Journal of Public Health study also found regional disparities, with MMR vaccination rates higher in the Midwest and Northeast compared to the South and West. Socioeconomic factors play a role as well, with parents on Medicare or Medicaid approximately 15% less likely to have their children receive the MMR vaccine compared to parents with private insurance.
Projected Impact of Changing Vaccination Rates
The JAMA modeling study explored multiple scenarios to understand how changes in vaccination rates might affect disease burden. If MMR coverage increased by just 5-10%, measles cases could be dramatically reduced to between 2,700 and 5,800 over the 25-year period. Conversely, a 10% drop in coverage could lead to 11.1 million measles cases.
More severe declines would have catastrophic consequences. A 25% decrease in vaccine coverage could result in 26.9 million measles cases, nearly 88,000 polio cases, and 80,600 deaths. At a 50% decline, poliovirus, rubella, and measles would all return to endemic status at varying speeds.
Dr. Eric Zhou, a pediatrics instructor at the Icahn School of Medicine at Mount Sinai and lead researcher on the American Journal of Public Health study, emphasized the importance of addressing these trends: "Addressing these disparities, through equitable access and fostering trust and transparency in vaccine safety, is key to protecting children from preventable diseases like measles."
Political Factors Influencing Vaccination Decisions
The research also highlighted the role of political affiliation in vaccination decisions. The American Journal of Public Health study found that Republican parents were 27% less likely to have their children receive the MMR vaccine compared to Democratic parents.
This political divide has raised concerns among public health officials, particularly with the recent appointment of Robert F. Kennedy Jr., a prominent vaccine skeptic, as HHS secretary. Some experts worry this could further complicate efforts to reverse declining vaccination rates.
Public Health Response and Recommendations
Both studies emphasize the critical need to maintain high vaccination coverage to prevent disease resurgence. The JAMA researchers concluded that "these findings support the need to continue routine childhood vaccination at high coverage to prevent resurgence of vaccine-preventable infectious diseases in the US."
Public health experts recommend targeted interventions to address vaccine hesitancy, including improved education about vaccine safety, increased access to vaccines for underserved populations, and clear communication about the risks of preventable diseases.
The CDC continues to monitor vaccination rates and disease outbreaks closely, with particular attention to measles, which appears to be the most immediate threat based on current trends. Health officials stress that maintaining vaccination rates above 95% is crucial for preserving herd immunity and preventing these once-controlled diseases from making a dangerous comeback.
