Measles is one of the most contagious viruses known. It spreads so easily that when an infected person coughs or sneezes, the virus can remain in the air for up to two hours. Anyone nearby who isn’t vaccinated faces a high risk of infection.
The recent measles outbreak in Texas, the worst in the state in three decades, underscores the persistent threat of this highly contagious virus. As of late February 2025, Texas has reported 124 cases, primarily among children, with one confirmed fatality, the first measles-related death in the U.S. since 2015. In a world with safe and effective vaccines, no child should suffer—or lose their life—to a disease we have the power to prevent.
This outbreak highlights the urgent need to maintain high vaccination rates, particularly as immunization levels have declined since the COVID-19 pandemic, fueling the resurgence of vaccine-preventable diseases. As I previously wrote, in the 2023–2024 school year, national vaccination coverage for key vaccines, including measles, mumps, and rubella (MMR), fell below 93%—a concerning drop from the pre-pandemic rate of 95%. Additionally, 3.3% of U.S. kindergartners had exemptions from at least one vaccine, the highest rate ever recorded, with 14 states exceeding a 5% exemption rate. These alarming trends undermine herd immunity and heighten the risk of outbreaks.
Measles outbreaks are often driven by a combination of factors, including international travel, declining vaccination rates both domestically and globally, pockets of unvaccinated communities, and persistent public misconceptions about vaccines. While most people recover, the complications can be severe: one in five cases leads to hospitalization, one in 20 develops pneumonia, one in 1,000 results in brain swelling and potential brain damage, and one to three per 1,000 may result in death. Furthermore, measles weakens the immune system, erasing immunological memory and increasing susceptibility to other infections.
Here are six key points to be aware of:
- Measles is vaccine-preventable. The MMR vaccine, administered in two doses, offers approximately 97% protection, while a single dose provides about 93%. The first dose is typically given at 12 to 15 months of age, followed by a second dose between 4 to 6 years.
- You’re fully vaccinated after two doses. The CDC considers individuals who received two doses of the measles vaccine in accordance with the U.S. vaccination schedule during childhood as having lifelong protection, eliminating the need for any future booster doses. However, while rare, breakthrough infections can occur in about three out of 100 fully vaccinated individuals exposed to the virus.
- Vaccination status confirmation. If you're uncertain about your vaccination status, consult your healthcare provider or attempt to locate your vaccination records. Those lacking documented immunity should receive at least one dose of the MMR vaccine, while certain groups may be advised to receive two doses.
- Certain groups remain susceptible to measles infection. This includes individuals born after 1957 who haven't received two doses of the live measles-containing vaccine (MMR), infants too young for vaccination, those who received an inactivated vaccine between 1963 and 1967 and haven't been re-vaccinated, and those who declined vaccination. People with compromised immune systems due to medical conditions or medication use are also at higher risk.
- Symptom vigilance. Be alert to symptoms if you suspect exposure or are in an area with a reported measles outbreak. Symptoms typically appear 7-14 days post-exposure, though this period can extend up to 21 days. Initial symptoms include high fever, cough, runny nose, red watery eyes, and a rash. The rash, characterized by tightly clustered small red spots, some slightly raised, often starts at the hairline and spreads over the face, neck, body, and eventually the limbs. The rash usually surfaces 2 to 4 days after fever onset and lasts around 5 to 6 days.
- Booster doses and early infant vaccination in outbreak areas. During measles outbreaks, the public health may recommend additional measures to enhance immunity. Infants as young as 6 months old may receive an early dose of the MMR vaccine if they reside in or travel to areas with active outbreaks, such as Texas. This dose does not count toward the routine two-dose series, meaning they will still need two additional doses at the recommended ages. Additionally, individuals in outbreak-prone areas who received only one dose of MMR should consider getting their second dose sooner rather than later.
For additional measles-related questions, check out The Centers for Disease Control and Prevention’s “Questions about Measles” or speak to your healthcare provider.