Measles cases are rising world-wide so now's the time to brush up on this previously rare life threatening and vaccine preventable illness.

This episode was written by pediatricians Tammy Yau and Lidia Park with content support from Ritu Cheema (pediatric infectious disease). Pediatricians Tammy and Lidia take full responsibility for any errors or misinformation.

Follow us on Twitter/X @Pediagogypod, Instagram/Threads @pediagogy, Bluesky @pediagogypodcast.bluesky.social, and connect with us at [email protected]

Key Points:

• Measles is a highly contagious vaccine preventable viral infection. From 1 single person infected with measles, an average of 18 people can be infected compared to an average of 10 for Ebola and an average of 6 for COVID.
• 2 doses of the live attenuated measles vaccine is 97% effective at preventing measles infection
• Herd immunity prevents wide-spread measles outbreaks. The threshold needed to prevent large scale measles outbreaks is 95%. Only 92.7% of kindergarteners in the US received both MMR shots for the 2023-2024.
• Symptoms of measles includes cough, conjunctivitis, coryza (rhinorrhea), Koplik spots (white spots in the mouth), and rash spreading from the face down, Serious complications include death (1-3 deaths per 1000 cases), encephalitis (20% mortality), and subacute sclerosing panencephalitis (SSPE) which is almost universally fatal.

Sources:

• “What’s Old is New Again: Measles”. Pediatrics (2025) 155 (6): e2025071332. 
• https://doi.org/10.1542/peds.2025-071332
• “CDC Confirms Worst Year for Measles since 1992”. AAP News. Sean Stangland. Jul 9 2025.
• “Vaccines Matter: Measles and Its Complications”. Pediatrics (2025) 156 (1): e2025071622. https://doi.org/10.1542/peds.2025-071622
• Mina MJ, Metcalf CJE, de Swart RL, Osterhaus ADME, Grenfell BT. Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality. Science. 2015;348(6235):694–699. PubMed doi: 10.1126/science.aaa3662
• Mina MJ, Kula T, Leng Y, et al. Measles virus infection diminishes preexisting antibodies that offer protection from other pathogens. Science. 2019;366(6465):599–606. PubMed doi: 10.1126/science.aay6485
• Lin WH, Kouyos RD, Adams RJ, Grenfell BT, Griffin DE. Prolonged persistence of measles virus RNA is characteristic of primary infection dynamics. Proc Natl Acad Sci U S A. 2012;109(37):14989-14994. doi:10.1073/pnas.1211138109
• AAP Red Book: Measles 
• Medical vs Nonmedical Immunization Exemptions for Child Care and School Attendance: Policy Statement. Pediatrics (2025) 156 (2): e2025072714. https://doi.org/10.1542/peds.2025-072714