[1/2] A vial of the measles, mumps, and rubella (MMR) vaccine is pictured at the International Community Health Services clinic in Seattle, Washington, U.S., March 20, 2019.
Measles is one of the most contagious human viruses and is almost entirely preventable through vaccination.
However, it requires 95% vaccine coverage to prevent outbreaks among populations.
A record high of nearly 40 million children missed a measles vaccine dose in 2021 due to hurdles created by the COVID pandemic, the WHO and the U.S. Centers for Disease Control and Prevention (CDC) said in a joint report.
While measles cases have not yet gone up dramatically compared to previous years, now is the time to act, the WHO's measles lead, Patrick O'Connor, told Reuters.