Measles, mumps and rubella vaccine(Merck Sharp & Dohme)

THURSDAY, March 13, 2025 -- A growing measles outbreak has led to 222 reported cases across Texas, New Mexico and Oklahoma in 2025, with health officials urging more people to get vaccinated. During an interview with Fox News , U.S. Health and Human Services (HHS) Secretary Robert F. Kennedy Jr . encouraged vaccination but also made misleading statements about vaccine-induced immunity, CNN reported. “When you and I were kids, everybody got measles, and measles gave you … lifetime protection against measles infection. The vaccine doesn’t do that. The vaccine is effective for some people for life, but for many people, it wanes,” Kennedy said in the interview. Dr. Paul Offit — director of the Vaccine Education Center at Children’s Hospital of Philadelphia who recently spoke with HealthDay about COVID — said that if vaccine-induced immunity waned significantly, measles would not have been declared eliminated in the U.S. in 2000. While antibody levels may decline over time, the immune system retains memory cells that provide long-term protection against the virus, Offit explained. Dr. Michael Mina , chief scientific officer of the telehealth company eMed and an infectious disease expert, emphasized that the outbreak is primarily driven by unvaccinated individuals, CNN said. "Even those who may have waning immunity will not transmit large amounts of virus," Mina said. Measles cases are often linked to international travel. Since measles was declared eliminated, the U.S. has averaged about 179 cases per year. This is the fifth year since then that cases have surpassed 100 and the third year to exceed 200, with past major outbreaks occurring in 2014 (linked to Disneyland) and 2019 (a nearly year-long outbreak in New York). Some, including Kennedy, have promoted natural immunity -- gained from infection -- over vaccination. But experts warn that natural infection can come with serious risks. Two doses of the MMR vaccine are 97% effective at preventing measles, providing strong and lasting immunity without the dangers of infection. “The goal of a vaccine is to induce the immunity that is a consequence of natural infection without paying the price of natural infection,” Offit said. Measles can lead to severe complications, especially in children. According to the U.S. Centers for Disease Control and Prevention (CDC): One of the two deaths linked to the current outbreak involved an unvaccinated school-age child . In his Fox News interview, Kennedy also falsely claimed that the MMR vaccine causes illnesses similar to measles, saying it “causes deaths every year. … It causes all the illnesses that measles itself causes: encephalitis and blindness, et cetera.” Experts refute this, however “The measles vaccine is incredibly safe,” Dr. Peter Hotez , co-director of the Texas Children’s Hospital Center for Vaccine Development and dean of the National School of Tropical Medicine at the Baylor College of Medicine, told CNN . “This is what anti-vaccine activists do is, they play up and try to scare you with the very, very rare side effects and forget to tell you about the horrific effects of the illness.” An older CDC and U.S. Food and Drug Administration (FDA) study found no evidence linking the MMR vaccine to serious health issues. “The MMR vaccine is extremely safe. The most common side effects that people may get is the low-grade fever for a few days, and sometimes people can get this temporary rash. It usually resolves within 24 to 48 hours. Those are by far the most common symptoms, and there are a few more that are much less common, but they are extremely rare,” Dr. Vivek Cherian , a Chicago-based internal medicine doctor, said to CNN . “All of those [common side effects] are signs that the vaccine is working and your immune system is mounting the responses it’s supposed to to gain memory to protect you later. But many folks are touting these as significant adverse events, and so I think that the devil is really in the details on this,” Dr. Christina Johns , a pediatric emergency physician at PM Pediatrics in Annapolis, Maryland, concluded. While Kennedy suggested that waning vaccine immunity plays a role in outbreaks, epidemiologist Katelyn Jetelina warns that the real issue may be a significant underreporting of measles cases "We’ve seen two deaths so far, yet only 228 cases have been reported. Measles typically kills 1 in 1,000 unvaccinated individuals. They were either extremely unlucky, or there are more cases than reported," Jetelina wrote on The Dose, a blog on the website Your Local Epidemiologist. Jetelina also pointed out that very sick hospitalized patients often indicate that families are delaying care, possibly due to misinformation or lack of trust in the medical system. The second measles fatality, an unvaccinated adult, never even sought hospital care, highlighting concerns about how many cases are going undetected. The CDC has now deployed a response team to help local and state epidemiologists track and contain the outbreak. However, Jetelina said front-line epidemiologists are facing resistance to case investigations, further complicating efforts to get an accurate picture of the outbreak. "We don’t just have a murky numerator (case count) -- we also have a murky denominator (population size). The community at the center of this outbreak is likely far larger than official U.S. Census figures suggest," she concluded. Whatever your topic of interest, subscribe to our newsletters to get the best of Drugs.com in your inbox.