The U.S. now has more than double the number of measles cases it saw in all of 2024, with Texas reporting another large jump in cases and hospitalizations on Friday. Other states with active outbreaks — defined as three or more cases — include New Mexico, Kansas, Ohio and Oklahoma. The virus has been spreading in undervaccinated communities, and since February, two unvaccinated people have died from measles-related causes. The multi-state outbreak confirms health experts’ fears that the virus will take hold in other U.S. communities with low vaccination rates and that the spread could last a year. The World Health Organization said last week that cases in Mexico are linked to the Texas outbreak. Measles is caused by a highly contagious virus that is airborne and spreads easily when an infected person breathes, sneezes, or coughs. It is preventable through vaccines and has been considered eliminated from the U.S. since 2000. Here’s what else you need to know about measles in the U.S. How many measles cases are there in Texas and New Mexico? Texas’ outbreak began more than two months ago. State health officials said Friday that 59 new cases of measles have been reported since Tuesday, bringing the total to 481 across 19 counties—most of them in West Texas. The state also logged 14 new hospitalizations, for a total of 56 throughout the outbreak. More than 65% of Texas’ cases are in Gaines County, population 22,892, where the virus is spreading in a close-knit, undervaccinated Mennonite community. The county has logged 315 cases since late January—just over 1% of its residents. New Mexico announced six new cases Friday, bringing the state’s total to 54. New Mexico health officials say the cases are linked to Texas’ outbreak based on genetic testing. Most are in Lea County, where two people have been hospitalized, and two are in Eddy County. A school-age child died of measles in Texas in late February, and New Mexico reported its first measles-related death in an adult on March 6. How many measles cases are there in Kansas? As of Wednesday, Kansas had 24 cases in six counties in the southwest part of the state. Kiowa and Stevens counties each have six cases, while Grant, Morton, Haskell, and Gray counties have five or fewer. The state’s first reported case, identified in Stevens County on March 13, is linked to the Texas and New Mexico outbreaks based on genetic testing, a state health department spokesperson said. However, health officials have not determined how the person was exposed. How many measles cases are there in Oklahoma? Cases in Oklahoma remained steady Friday: eight confirmed and two probable cases. The state health department said the first two probable cases were “associated” with the West Texas and New Mexico outbreaks. A state health department spokesperson confirmed measles exposures in Tulsa and Rogers counties but wouldn’t say which counties had cases. How many measles cases are there in Ohio? Ohio reported one new measles case Thursday in west-central Allen County. Last week, there were 10 in Ashtabula County in the state’s northeast corner. The first case was in an unvaccinated adult who had interacted with someone who had traveled internationally. In central Ohio, Knox County officials reported two new measles cases in international visitors, for three cases in international visitors total. Those cases are not included in the state’s official count because they are not in Ohio residents. A measles outbreak in central Ohio sickened 85 in 2022. Where else is measles showing up in the U.S.? Measles cases also have been reported in Alaska, California, Colorado, Florida, Georgia, Kentucky, Maryland, Michigan, Minnesota, New Jersey, New York, Pennsylvania, Rhode Island, Tennessee, Vermont, and Washington. The U.S. Centers for Disease Control and Prevention define an outbreak as three or more related cases. As of Friday, the agency counted six clusters that qualified as outbreaks in 2025. In the U.S., cases and outbreaks are generally traced to someone who caught the disease abroad. It can then spread, especially in communities with low vaccination rates. In 2019, the U.S. saw 1,274 cases and almost lost its status of having eliminated measles. So far in 2025, the CDC’s count is 607. Do you need an MMR booster? The best way to avoid measles is to get the measles, mumps, and rubella (MMR) vaccine. The first shot is recommended for children between 12 and 15 months old, and the second for children between 4 and 6 years old. Scott Weaver with the Global Virus Network, an international coalition, said people at high risk for infection who got the shots many years ago may want to consider getting a booster if they live in an area with an outbreak. These may include family members living with someone who has measles or those especially vulnerable to respiratory diseases because of underlying medical conditions. The CDC said that adults with “presumptive evidence of immunity” generally don’t need measles shots now. Criteria include written documentation of adequate vaccination earlier in life, lab confirmation of past infection or being born before 1957, when most people were likely to be infected naturally. A doctor can order a lab test called an MMR titer to check your levels of measles antibodies, but health experts don’t always recommend this route and insurance coverage can vary. The CDC says getting another MMR shot is harmless if there are concerns about waning immunity. People who have documentation of receiving a live measles vaccine in the 1960s don’t need to be revaccinated, but people who were immunized before 1968 with an ineffective measles vaccine made from “killed” virus should be revaccinated with at least one dose, the agency said. That also includes people who don’t know which type they got. What are the symptoms of measles? Measles first infects the respiratory tract, then spreads throughout the body, causing a high fever, runny nose, cough, red, watery eyes and a rash. The rash generally appears three to five days after the first symptoms, beginning as flat red spots on the face and then spreading downward to the neck, trunk, arms, legs and feet. When the rash appears, the fever may spike over 104 degrees Fahrenheit, according to the CDC. Most kids will recover from measles, but infection can lead to dangerous complications such as pneumonia, blindness, brain swelling and death. How can you treat measles? There is no specific treatment for measles, so doctors generally try to alleviate symptoms, prevent complications, and keep patients comfortable. Why do vaccination rates matter? In communities with high vaccination rates—above 95%—diseases like measles have a harder time spreading. This is called “herd immunity.” But childhood vaccination rates have declined nationwide since the pandemic and more parents are claiming religious or personal conscience waivers to exempt their kids from required shots. The U.S. saw a rise in measles cases in 2024, including an outbreak in Chicago that sickened more than 60. What is measles? Measles is a respiratory virus that can survive in the air for up to two hours. According to the U.S. Centers for Disease Control and Prevention, up to nine out of 10 people who are susceptible will get the virus if exposed. Most kids will recover from measles if they get it, but infection can lead to dangerous complications like pneumonia, blindness, brain swelling, and death. Is the vaccine safe? Yes, the measles, mumps and rubella (MMR) vaccine is safe and highly effective in preventing measles infection and severe cases of the disease. The first shot is recommended for children between 12 and 15 months old, and the second for children between 4 and 6 years old. The vaccine series is required for kids before kindergarten in public schools nationwide. Before the vaccine was introduced in 1963, the U.S. saw some 3 million to 4 million cases per year. Now, there are usually fewer than 200 in a normal year. There is no link between the vaccine and autism, despite a now-discredited study and health disinformation. Why do vaccination rates matter? In communities with high vaccination rates — above 95% — diseases like measles have a harder time spreading through communities. This is called “herd immunity.” But childhood vaccination rates have declined nationwide since the pandemic and more parents are claiming religious or personal conscience waivers to exempt their kids from required shots. The U.S. saw a rise in measles cases in 2024, including an outbreak in Chicago that sickened more than 60. Five years earlier, measles cases were the worst in almost three decades in 2019. Gaines County has one of the highest rates in Texas of school-aged children who opt out of at least one required vaccine, with nearly 14% of K-12 children in the 2023-24 school year. Health officials said that number is likely higher because it doesn’t include many children who are homeschooled and whose data would not be reported. What are public health officials doing to stop the spread? Health workers are hosting regular vaccination clinics and screening efforts in Texas, as well as working with schools to educate people about the importance of vaccination and offering shots. 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