The South Carolina measles outbreak has surpassed the recorded case count in Texas' 2025 outbreak, as health officials have logged almost 600 new cases in just over a month.
The outbreak centered in northwestern Spartanburg County is showing little sign of slowing down, with health officials saying Tuesday that 789 cases have been confirmed since September. Last year in Texas, 762 cases were reported, although experts believe that was likely an undercount.
A large outbreak on the Utah-Arizona border is also ongoing, and the United States' measles elimination status is at risk.
CDC routine vaccination recommendations to protect against measles
Children
CDC recommends two doses of measles-containing vaccine routinely for children, starting with the first dose at age 12 through 15 months and the second dose at age 4 through 6 years before school entry. This can be administered as MMR or MMRV vaccine. Children can receive the second dose of MMR vaccine earlier than 4 through 6 years, as long as it is at least 28 days after the first dose. A second dose of MMRV vaccine can be given 3 months after the first dose up to 12 years of age. CDC recommends that separate MMR and varicella vaccines be given for the first dose in children aged 12–47 months; however, MMRV may be used if parents or caregivers express a preference.
Adults
Adults should also be up to date on MMR vaccinations with either 1 or 2 doses (depending on risk factors) unless they have other presumptive evidence of immunity to measles, mumps, and rubella. One dose of MMR vaccine, or other presumptive evidence of immunity, is sufficient for most adults. Providers generally do not need to actively screen adult patients for measles immunity in non-outbreak areas in the U.S. After vaccination, it is also not necessary to test patients for antibodies to confirm immunity. There is no recommendation for a catch-up program among adults for a second dose of MMR (e.g., persons born before 1989 or otherwise).
As of Thursday, the U.S. Centers for Disease Control and Prevention had confirmed 416 measles cases nationwide this year, nearly 20% of the 2025 case total. The other states with confirmed cases in 2026 are: California, Florida, Georgia, Idaho, Kentucky, Minnesota, North Carolina, Ohio, Oregon, Virginia and Washington.
Last year was the nation's worst year for measles spread since 1991, according to the CDC. The U.S. confirmed 2,255 cases and nearly 50 different outbreaks. Three people died, all of them unvaccinated, including two children in Texas.
Measles is caused by a highly contagious virus that's airborne and spreads easily when an infected person breathes, sneezes or coughs. A vaccine can prevent it.
Measles first infects the respiratory tract, then spreads throughout the body, causing a high fever, runny nose, cough, red, watery eyes and a rash. Most people recover, but infection can lead to dangerous complications such as pneumonia, blindness, brain swelling and death.
The CDC defines an outbreak as three or more related cases.
How many measles cases are there in South Carolina?
South Carolina has logged 789 cases as of Tuesday in an outbreak centered in Spartanburg County. Officials confirmed 89 new cases since Friday.
The outbreak has rapidly grown in the last month to the worst in the nation. Hundreds of children across dozens of schools have been quarantined because of measles exposures, some more than once. The outbreak has also spread to North Carolina and Ohio.
How many measles cases are there in Utah and Arizona?
Health officials are still responding to an outbreak in an area nicknamed Short Creek — the border towns of Hildale, Utah, and Colorado City, Arizona.
Arizona health officials have documented 222 in Mohave County, and in recent days a small number of cases were detected for the first time in Maricopa, Pima and Pinal counties. Utah officials have confirmed 216 cases, 55 of them in the past three weeks.
Experts in both states have said they are concerned about undercounts.
What do you need to know about the MMR vaccine?
The best way to avoid measles is to get the measles, mumps and rubella vaccine. The first shot is recommended for children between 12 and 15 months old and the second between 4 and 6 years old.
After two doses, the shot is 97% effective against measles and its protection is considered lifelong.
Measles has a harder time spreading through communities with high vaccination rates — above 95% — due to "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.
