Doctors Reveal the Number-1 Group Who Should Be Most Concerned About Measles Right Now

Key Points:

• In 2026, the U.S. has reported 3,294 confirmed measles cases across 47 states, with Pennsylvania being a major hotspot, recording 731 cases and four deaths so far, according to the CDC and Pennsylvania Department of Health.
• Vulnerable groups include infants under 12 months who are too young for vaccination, unvaccinated pregnant people who cannot receive the live MMR vaccine during pregnancy, and immunocompromised individuals who may not safely receive the vaccine.
• People who are vaccinated with one or two doses of the MMR vaccine or who had natural measles infection generally have strong protection, with two doses being 97% effective; in outbreak areas, vaccination can be given to children as young as six months.
• Measles remains a serious disease causing complications such as pneumonia, encephalitis, death, and immune amnesia, which reduces immunity to other infections, though public perception often underestimates its severity due to its previous elimination in the U.S.
• Health experts urge unvaccinated individuals or those uncertain about their vaccination status to get the MMR vaccine promptly, and recommend contacting healthcare providers before in-person visits if measles symptoms appear to prevent further spread.