A measles outbreak that began in Texas at the start of the year has infected over 300 people as of Tuesday, as cases of the highly contagious illness have been spotted in 17 states and already exceeded the total number of measles cases reported in 2024.

The measles vaccine uses a weakened virus that's never been shown to spread to others. Samples from the outbreak in Texas also show that a wild-type virus is responsible. Yet, social media posts have falsely claimed that the outbreak is due to a vaccine strain.