A measles advisory is shown tacked to a bulletin board outside Gaines County Courthouse on April 09, 2025 in Seminole, Texas.
The CDC has reported a total of 1,001 confirmed measles cases in the United States so far this year. This figure marks the second-highest count we’ve seen in 25 years, only surpassed by 2019, which saw over 1,200 cases. The most effective way to control measles outbreaks is through receiving two doses of the MMR vaccine, which covers measles, mumps, and rubella.
Understanding how measles is spreading right now can be complex, but here are some key numbers.
1,001 cases:
The CDC tracks confirmed cases and updates their count each week. On May 2, the total was reported as 935. Just recently, it crossed the thousand mark to 1,001.
31 jurisdictions:
This year, measles cases have been noted in 31 jurisdictions, a slight increase from 30 as of May 1. Cases span more than half of the U.S. states, although not all of them are experiencing full-scale outbreaks.
14 outbreaks:
An outbreak is defined as three or more related cases. While the total number of cases is significant, the number of outbreaks highlights where the virus is actively spreading. This week, outbreaks increased from 12 to 14.
The largest outbreak is in west Texas, where measles has been circulating since January, leading to 683 reported cases last week and 709 this week.
3 deaths:
Regrettably, two unvaccinated children in Texas have died from the disease. In New Mexico, an adult was diagnosed with measles posthumously.
18 people:
In unvaccinated populations, one person with measles could potentially infect up to 18 others. In contrast, if 82% of a population is vaccinated, an infected person typically spreads the virus to only 2 to 3 others on average.
95% vaccination rate:
The CDC indicates that to effectively curb outbreaks, a community needs a vaccination rate of 95%. If the rate falls below that, which could happen if a community is not adequately vaccinated, herd immunity begins to weaken. In Gaines County, Texas, which is currently dealing with the outbreak, the vaccination rate for kindergarteners is just under 82%.
Herd immunity refers to a scenario where enough members of the community are immune, making continual transmission of the virus unlikely. It also safeguards those with weakened immune systems and children who have not yet received both doses of the measles vaccine.
12 months:
A crucial question remains about how long measles might continue its spread in the U.S. Since the Texas outbreak began in January, if it persists for over 12 months, the country risks losing its measles “elimination” status, which signifies effective control for a year or more. This status has been maintained for roughly 25 years.
