Both Merck and GSK make measles, mumps and rubella (MMR) vaccines in the U.S., crucial offerings as a measles outbreak in Texas continues.
Following a second measles-related death in Texas, Robert F. Kennedy Jr., head of the federal Department of Health and Human Services, endorsed the measles, mumps, and rubella (MMR) vaccine in a lengthy social media post—seemingly reversing some of his previous comments about vaccines and the outbreak.“The most effective way to prevent the spread of measles is the MMR vaccine,” RFK Jr. wrote on the social media website X on April 6. Both children who died during the recent measles outbreak were unvaccinated, according to Texas officials.The current outbreak is centralized in Texas, with 499 of the 642 confirmed U.S. measles cases coming from the state as of April 6, according to RFK Jr. In March, the health secretary deployed a CDC team to "bolster local and state capacity" for responding across multiple regions in Texas, supply pharmacies with MMR vaccines, and support schools and facilities with contact investigations and community outreach. CDC teams are now back in Texas at the governor's request. Measles vaccine makers are also on the case.Merck, which brought the first MMR vaccine to the U.S. in the 1970s with its M-M-R II, is “committed to providing help to support the current outbreak response efforts,” a Merck spokesperson said in a statement to Fierce Pharma. The company is focused on ensuring the availability of its vaccine for “those who need it most,” and it is “closely monitoring the situation” including outbreak trends and the potential demand for its MMR vaccine.“Based upon current known demand, there is an adequate supply of Merck’s M-M-R II vaccine to support appropriate vaccination of eligible patients,” the company representative said. “Adherence to recommended pediatric vaccination schedules and regular health visits is critical to protecting public health and mitigating outbreaks of these preventable diseases."Since the MMR vaccines were introduced, measles cases have substantially declined in the U.S. The latest outbreak has already resulted in more cases than the total reported in all of 2024, when 285 measles cases were documented. The measles spread hit a high in 2019 with 1,274 cases reported, but quickly quelled in 2020 with just 13, according to the CDC.For context, measles in the U.S. peaked at over 27,000 reported cases in 1990 before the widespread implementation of MMR vaccine. Two doses of the MMR vaccine are proven to be 97% effective against measles. Still, measles vaccination rates for young children are steadily decreasing, according to a recent report by Truveta Research. RFK Jr. has previously held a questionable stance on the MMR vaccine, telling Fox News’ Sean Hannity in early March that the measles vaccine “wanes” for some people and that the measles infection itself offers “lifetime immunity.” He further noted that the MMR vaccine “causes deaths every year” and “all the illnesses that measles itself causes,” CNN reported from the Fox interview.According to the CDC, serious risks of MMR vaccination are rare. There is a “very remote chance” of the vaccine causing a severe allergic reaction, serious injury or death, the CDC points out.Along with promoting the MMR vaccine, RFK Jr. has touted alternative regimens that include aerosolized budesonite and clarithromycin. Hours after writing his recent X post, the health secretary also pointed to two “extraordinary healers” in a separate post who have “treated and health some 300 measles-stricken Mennonite children” using the alternative treatment. There is currently no FDA-approved treatment or cure for measles, but vitamin A has been recommended for treating severe cases.Merck’s family of measles vaccines includes a ProQuad shot, which lumps chicken pox (varicella) protection into an MMR vaccine (MMRV). The company’s MMRV vaccine franchise brought in $2.5 billion in 2024, reflecting sales slightly up from 2023.GSK also markets Priorix, another MMR vaccine. The drugmaker brought its offering to the U.S. in 2022 after introducing it years ago in Europe, adding a key option to the country’s MMR arsenal. Priorix and M-M-R II are both recommended by the CDC’s vaccine committee for routine vaccination.