Florida Republican gubernatorial nominee U.S. Rep. Byron Donalds told Face the Nation that the recent measles surge in parts of the country is the result of “rampant illegal immigration” during the previous administration. He cited outbreaks in El Paso, Texas and southwest Florida, urging parents to vaccinate their children and calling for tighter immigration controls.
Experts say vaccination gaps, not immigration, fuel the outbreak
In‑depth interviews with epidemiologists and infectious‑disease specialists reveal that the overwhelming cause of the 2026 measles spike is a decline in MMR (measles, mumps, rubella) vaccination coverage. Around 94% of confirmed cases involve people who are unvaccinated or whose vaccination status is unknown. Dr. George Rust, a professor of epidemiology at Florida State University, explained that measles typically enters the United States when unvaccinated travelers return from abroad, and then spreads in pockets of unvaccinated residents.
Dr. Paul Spiegel of Johns Hopkins University added that “any introduction becomes an outbreak only when the virus reaches enough susceptible, unvaccinated people,” and that data do not point to migrants as a source. Similarly, Dr. William Schaffner of Vanderbilt University noted that the “very substantial majority” of cases are caused by U.S. children who travel overseas and bring the virus back, with only a minority linked to foreign nationals.
Immigration numbers and health data do not support the claim
The Biden administration released roughly 4.3 million people into immigration courts, far short of the 10 million figure cited by Donalds. Moreover, the CDC does not track measles cases by immigration status, making it impossible to tie outbreaks to illegal entrants. Past outbreaks, such as the early‑2026 incident at an ICE detention facility in El Paso, were traced to poor facility conditions and lack of vaccination data, not to recent arrivals.
Countries from which many undocumented migrants originate—Mexico, Guatemala, Honduras—include the MMR vaccine in their routine childhood schedules. Recent measles activity in those nations is also driven by gaps in vaccination coverage, mirroring the U.S. situation.
Public‑health implications for Florida families
Florida’s immunization rate remains below the 95% threshold needed for herd immunity, according to CBS News. Health officials stress that the most effective protection is the two‑dose MMR series, which is 97% effective. Unvaccinated individuals exposed to measles have a roughly 90% chance of infection, and complications can include pneumonia, brain swelling, and death.
As the state grapples with record‑breaking case numbers—surpassing the 2025 outbreak, the worst since 1991—local health departments continue to urge parents to ensure their children are fully vaccinated, regardless of immigration debates.
Original reporting: NBC6 Miami — read the source article.
