Uh … Am I Protected Against Measles? It Might Depend On When You Were Born. – Slate

Sign up for the Slatest to get the most insightful analysis, criticism, and advice out there, delivered to your inbox daily.If you’ve been carefully tracking the measles outbreak in the Southwest, you know that two people with the illness have died. Both were unvaccinated, and one was an otherwise healthy 6-year-old. You know that the child’s Mennonite community in West Texas continues to get hit hard, with 223 cases as of Tuesday. And you know that there’s another cluster of cases in New Mexico—where the second death occurred—that’s genetically linked to the Texas outbreak.Given all that, you might also be wondering if you need to do anything to protect yourself and your loved ones: Am I vaccinated enough? Do I need a measles booster? Should I confirm that I’m immune by taking something called a titer test?“It’s the question du jour,” says William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center.It makes sense to worry: “Measles is not a trivial disease,” Schaffner reminds me. Quite the opposite: Although measles, the most contagious virus on record, doesn’t have a super high mortality rate (1 to 3 in every 1,000 infected people will die), it sends 20 percent of unvaccinated people to the hospital—and that number is higher for children under 5—with serious complications ranging from pneumonia to brain swelling. Basically, you are right to not be reassured by that mortality rate. “We shouldn’t only be talking about death,” says Jess Steier, CEO of the public health data science consulting firm (and podcast) Unbiased Science. “We want to avoid infection at all costs.”The good news is that we have an effective and safe vaccine that does exactly that: For most people, it completely prevents infection (unlike, say, the flu vaccine, which may solely ease symptoms, not prevent you from getting the flu entirely). Thanks to the measles vaccine, usually called the MMR vaccine, in combination with mumps and rubella, the U.S. declared measles to be effectively eliminated in 2000. The reason it’s coming back is that people are unvaccinated. To reach herd immunity—enough of a population being immune that measles can no longer spread—about 95 percent of people need to be vaccinated. In the Texas community where the child died during the outbreak, the measles vaccination rate among kindergartners is 82 percent.If you are healthy, got two doses of MMR, and were born after 1989: you’re good. “The recommendation is, sit pretty,” says Steier. Two doses of MMR provides lifetime protection for about 97 percent of people. (The other 3 percent may still get measles but will likely have milder symptoms and be less able to spread the virus than they would otherwise.) So if you were vaccinated after 1989, there’s absolutely no need to get a booster.If you were born before 1957, you also don’t need to worry about vaccination. You were born at a time when measles still ran rampant, so you almost certainly had the virus as a kid and are now immune. It’s not the ideal way to get immunity, but congratulations! You have it.If you were born between 1957 and 1989, you should pull out your vaccination records to review your history, says Schaffner. People born between 1957 and 1967 were getting vaccinated, but some received a version of the vaccine that was less effective than the one we use today. And many born between 1967 and 1989 got only one dose of MMR, which was the recommendation at the time but means they’re less likely to be fully protected. If you received the less effective vaccine or got just one shot, it’s a good idea to get a booster vaccine.Then there’s the other category: people who aren’t sure. Perhaps you can’t find your vaccination records, you were born in 1989, or you have no idea which version of the vaccine you got. If you really don’t know, the answer is simple. “Go into your health care provider, roll up your sleeve, and ask for a dose of MMR,” says Schaffner. (An exception is if you’re pregnant, in which case it’s recommended that you wait to vaccinate.) Even if you don’t need another MMR dose, it won’t hurt to get the extra one.Another key exception here is for people who are severely immunocompromised, such as cancer patients receiving chemotherapy. MMR is a live vaccine, and the worry is that it could replicate and cause illness if a recipient’s immune system is too weak. It’s also worth noting that people who were vaccinated before becoming immunocompromised may face reduced immunity. This population relies on herd immunity to stay safe from measles. That is why getting vaccinated is more than a personal decision. And yet, worrying about our own personal health is one of the limited things we can do right now when it comes to the scary spread of measles: “While we can’t fully control our environment, we can control our own immunization status,” writes infectious disease epidemiologist Nina Masters in her newsletter Know Your Vax.You might have heard about a titer test, which looks at the amount of antibodies in a person’s blood in order to confirm that they are immune. It’s a common service, but in most cases, some experts argue, if you’re that unsure of your status for measles, you should just get a booster. Checking titers requires an extra doctor’s visit and extra expense, so it’s a hassle. Plus, titers don’t provide a complete picture of your immunity, says Steier. Even if your antibody levels come back low, you have what are called memory B cells, which could be helping to protect you—and because they don’t make much antibody, they won’t really show up on that test. If you feel as if you have to do something, skip the titers and get the booster.But unless you’re in the heart of an outbreak, don’t worry too much. “You don’t need to run to your practitioner,” says Schaffner. The next time you’re at the doctor, though, ask them to review your vaccination history. It’s always a good idea to make sure you’re fully protected.Slate is published by The Slate
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Source: https://slate.com/technology/2025/03/measles-outbreak-vaccine-booster-titers.html