Measles Cases Surge in 2025: Key Facts and Prevention Tips

As of February 28, 2025, the United States is facing a significant measles outbreak, with over 164 confirmed cases, in 9 states. Most of these cases (153) are part of an outbreak occurring in Texas and eastern New Mexico. The infections have predominantly impacted unvaccinated children and teenagers in rural communities, and have resulted in over 30 hospitalizations.^1–3 This surge has tragically resulted in the first U.S. measles-related death in a decade—an unvaccinated school-aged child who was otherwise healthy. Here’s what you need to know about keeping your family safe from measles.

Current outbreak – by the numbers (As of February 28, 2025¹)

Total Cases: 164

Measles can be serious
Historically, measles has posed serious health risks. According to the World Health Organization, before the introduction of the vaccine in 1963 and widespread vaccination, major epidemics occurred around the world approximately every two to three years and caused an estimated 2.6 million deaths each year.⁴ In recent times, about 1 in 5 unvaccinated individuals who contract measles require hospitalization, and 1–3 out of every 1,000 cases result in death, even with modern medical care.¹ Infection with the measles virus has significant long-term effects on the immune system, which can lead to increased susceptibility to other infections for years after the initial measles infection.^5,6

Common symptoms of measles infection are fever, cough, runny nose, irritated eyes, and rash, though some people experience more serious complications from measles infection. Children under 5 years old, adults over 20 years old, pregnant women, and those who are immunocompromised are at high risk for more severe disease.

Serious complications include:

• Hospitalization
• Pneumonia
• Encephalitis (brain swelling) that can lead to deafness or intellectual disability
• Pregnancy complications in unvaccinated mothers, including low birth weights and premature birth
• Death

Measles is very contagious
Measles is extremely contagious, with 90% of unvaccinated individuals contracting the virus after exposure to an infected person.⁷ The virus spreads through airborne droplets when an infected person coughs or sneezes and can remain in the air for up to two hours. It can also be transmitted by touching contaminated surfaces and then touching the face, nose, or eyes. An infected person can unknowingly spread measles from four days before the rash appears to four days after.

Measles infections are preventable
The Measles, Mumps, and Rubella (MMR vaccine) is 93% effective against measles infection, provides long-term protection, and protects against mumps and rubella infections. Common side effects of the vaccine include sore arm from the shot, redness around the injection site, fever, and a mild rash.⁸ The CDC recommends that all children get two doses of MMR vaccine starting with the first dose at 12–15 months of age, and the second dose at 4–6 years of age.⁹ Teenagers and adults who were not vaccinated as children should become up to date with their vaccinations. People who were vaccinated from 1963–1968 with either inactivated (killed) measles vaccine or measles vaccine of unknown type should be revaccinated with at least one dose of the current vaccine. This recommendation is intended to protect those who may have received killed measles vaccine, which was available at this time and was not effective.⁹ Those born before 1957 are presumed to have naturally induced immunity, because they were likely exposed to measles before vaccines became available. There are blood tests that can confirm prior infection by measuring antibodies to the measles virus. If no evidence of prior exposure is found, these individuals should receive at least one dose of MMR vaccine.

It is also important to be vaccinated if traveling internationally; the CDC has an online tool to help determine whether a person may need additional doses of vaccine before travelling. People who are pregnant, have a weakened immune system, have a blood disorder, or have had an allergic reaction to a previous MMR vaccine, should talk with their healthcare provider before getting an MMR vaccine.⁹

References

1. CDC. Measles Cases and Outbreaks. Centers for Disease Control and Prevention https://www.cdc.gov/measles/cases-outbreaks.html (2024).
2. Measles. https://www.nmhealth.org/about/erd/ideb/mog/.
3. Measles Outbreak – Feb. 25, 2025 | Texas DSHS. https://www.dshs.texas.gov/news-alerts/measles-outbreak-feb-25-2025.
4. Measles. https://www.who.int/news-room/fact-sheets/detail/measles.
5. Mina, M. J., Metcalf, C. J. E., de Swart, R. L., Osterhaus, A. D. M. E. & Grenfell, B. T. Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality. Science 348, 694–699 (2015).
6. Mina, M. J. et al. Measles virus infection diminishes preexisting antibodies that offer protection from other pathogens. Science 366, 599–606 (2019).
7. CDC. Measles is Easily Transmitted. Centers for Disease Control and Prevention https://www.cdc.gov/measles/transmission.html (2020).
8. Measles-Mumps-Rubella (MMR) Vaccine Information Statement | CDC. https://www.cdc.gov/vaccines/hcp/vis/vis-statements/mmr.html (2023).
9. Measles, Mumps, and Rubella (MMR) Vaccination | CDC. https://www.cdc.gov/vaccines/vpd/mmr/public/index.html (2023).