A large, deadly measles outbreak in West Texas and New Mexico continues to grow. And while experts say the biggest risk is to unvaccinated people, some who were vaccinated decades ago may need updated shots to ensure they鈥檙e protected. It鈥檚 probable that at least some people in the affected age range are teachers and other school staff.
Most people who are vaccinated against measles are thought to be protected for the rest of their lives. But during a five-year span, from 1963 to 1968, a version of the measles vaccine was available that was later found to be less effective and later withdrawn. Unlike today鈥檚 far more effective vaccines, the version that was withdrawn did not use a live version of the measles virus.
Experts say people who received that vaccine should get a new vaccination now to bolster their protection against the disease.
Although the number of people who received the less effective vaccine is believed to be very small鈥攅stimated at 600,000 to 900,000 people in the United States鈥攕ome teachers and school staff could be in that group. People 鈥渂orn after 1957 but vaccinated before 1968鈥� could be among the affected group, .
About 17 percent of public school teachers were over the age of 55 as of 2020-21, according to , and about 10 percent of superintendents were 60 or older in 2024, , The School Superintendents Association.
People who work in schools鈥攅specially teachers鈥攁re particularly vulnerable to illnesses. They are frequently exposed and often congregate in group settings.
The Texas outbreak had grown to more than 120 cases as of Feb. 27, and one child, who was unvaccinated, has died, according to health officials. It鈥檚 the largest measles outbreak in the United States since 2019 and the country鈥檚 first measles death since 2015. Nearly all of the confirmed cases have been among people who were unvaccinated, and primarily occurred among school-aged children.
Measles is highly contagious鈥攁bout 90 percent of unvaccinated people who are exposed to the disease will end up contracting it, according to the U.S. Centers for Disease Control and Prevention. It causes symptoms including a high fever, cough, runny nose, and watery eyes, and comes with a trademark red rash that usually first appears on the forehead. An infection .
people who are unsure of their vaccination status, or believe they were vaccinated during the years the less effective vaccination was in circulation, review their records to determine if they should get a booster. People without access to their vaccination records could consider getting a booster vaccine anyway鈥攖here is no harm in doing so, according to Johns Hopkins.
The measles vaccination鈥攚hich is included in a vaccine that also protects against mumps and rubella鈥攊s about 97 percent effective when both doses have been administered, and about 95 percent effective with one dose, according to the CDC. It is recommended that children receive the first dose of the vaccine when they are 12 to 15 months old and the second between the ages of 4 and 6.
Gaines County, the epicenter of the West Texas outbreak, has one of Texas鈥� highest rates of exemptions from school vaccine requirements, and has had one of the state鈥檚 highest rates for years.
For the 2023-24 school year, nearly 18 percent of Gaines County kindergarteners had a conscientious exemption to vaccine requirements; the rate for all of Texas was less than 4 percent, according to the state health department, though that figure had risen from just over 1 percent in 2013-14.
Nationally, vaccination coverage among kindergartners , while exemptions from one or more vaccines among kindergarteners increased to 3.3 percent, from 3 percent the year prior.
The CDC recommends striving for a vaccination rate of about 95 percent to achieve herd immunity.
