07/17/2026
There’s a confirmed breakthrough measles case in Teton Valley, Idaho. Here’s what that means.
A breakthrough case is when a fully vaccinated person still gets sick. Two doses of MMR are about 97% effective, which is great but not 100%. The upside: breakthrough cases are usually milder, shorter, and less contagious.
🤒 Watch for fever, cough, runny nose, red eyes, or rash. If symptoms show up, call your provider before walking in, even if you’re vaccinated.