A major measles outbreak, the largest in 25 years, is sweeping across the US Southwest, Mexico, and Canada, fueled by low vaccination rates. Two children and one adult have died in the US outbreak, which has seen nearly 1,000 confirmed cases. Immunologists warn this signifies a "post-herd-immunity world," exacerbated by misinformation spread by US Health Secretary Robert F. Kennedy Jr., who promotes unproven treatments and undermines vaccine confidence. The outbreak highlights the urgent need for increased vaccination rates and combating vaccine misinformation.

Prepared by Olivia Bennett and reviewed by editorial team.