Byron Donalds Blames Measles Outbreaks on Immigration. The CDC's Own Numbers Say Otherwise.

It isn't. About 94% of confirmed U.S. measles cases in 2026 involve people who are unvaccinated or whose vaccination status is unknown ^[2][3]. Kindergarten MMR coverage nationally has slipped from 95.2% before the pandemic to 92.4% in the 2025–2026 school year — below the roughly 95% threshold needed for herd immunity — and schools under 80% coverage saw measles exposure in 73% of cases, versus just 5% for schools above 95% ^[3].

The specific outbreaks Donalds cited don't support his claim either. The El Paso cluster he named occurred inside ICE detention facilities — 136 confirmed cases, 16 of them at the Camp East Montana facility — driven by poor conditions and incomplete vaccination records, not by people arriving unvaccinated from abroad ^[2][3]. The Southwest Florida outbreak he also cited, centered on Ave Maria University with 107 cases, was traced to a student's out-of-state holiday travel, with no immigration link at all ^[2][3]. CDC data for the first four months of 2025 show only 6% of measles cases were internationally imported, and 92% of those importations were U.S. residents who had traveled abroad and returned — not new arrivals ^[1]. The CDC does not even track the immigration status of measles patients ^[1].

The country's largest 2025 outbreaks — 762 cases tied to Mennonite communities in Gaines County, Texas, and clusters in Utah's Fundamentalist Church communities and South Carolina's evangelical schools — all trace to low-vaccination religious communities, not immigration ^[2]. One irony fact-checkers flagged: Mexico's own 2025 measles outbreak was seeded by an unvaccinated Mennonite child visiting from Texas — the traffic ran the opposite direction from Donalds' claim ^[2]. Donalds also cited a figure of 10 million people entering illegally under Biden; PolitiFact found the actual number released to await court hearings was roughly 4.3 million ^[2].

This wasn't a stray comment — it came from a sitting congressman who is his party's nominee for governor of the third-largest U.S. state, delivered on a top Sunday news program and immediately clipped and amplified by conservative outlets covering the interview ^[1]. The claim reached a national audience within hours, prompting rebuttals from three independent fact-checking operations — FactCheck.org, PolitiFact, and North Carolina's WRAL — within the same week ^[2][3][4].

The timing matters: Donalds made the claim in the same breath as declining to clearly recommend vaccination to Florida parents, at a moment when nearly all of Florida sits below the immunization rate needed for measles herd immunity ^[1][3]. Public health specialists interviewed by FactCheck.org said there is "no data" linking illegal immigration to the outbreaks, and stressed that transmission depends on how many unvaccinated people a virus reaches — not where the virus originated ^[3][4].

FALSE. CDC surveillance data show the driver of the 2026 U.S. measles outbreak is falling MMR vaccination coverage, not illegal immigration. The specific outbreaks Donalds named — El Paso and Southwest Florida — were caused by detention-facility conditions and domestic student travel, respectively, and international importation accounts for a small single-digit share of cases nationally, most of it from vaccinated U.S. travelers rather than immigrants ^[1][2][3]. PolitiFact rated the claim False outright ^[2].