Abstract
As of May 2025, measles outbreaks have been occurring worldwide. Japan has reported the
highest number of cases since the beginning of the COVID-19. Unvaccinated measles cases are
highly contagious and at high risk for serious illness, so it is important to ensure that children
receive the live attenuated measles-rubella (MR) vaccine as soon as they become one year old.
Additionally, the second routine immunization coverage rate must be raised to 95% or higher
among five-to six- year-old children (one year before entering elementary school). For elementary
school students and older individuals, it is important to check the vaccine records showing two
doses of a measles-containing vaccine administered at or after one year of age. Those born on or
after April 2, 1990, had the opportunity to receive two routine vaccinations; however, their records
must be checked to confirm receipt. We also recommend checking vaccination records before
traveling abroad. Additionally, rapid active epidemiological surveillance should be conducted in the
event of a single measles case. Emergency vaccination within 72 hours of exposure for susceptible
individuals may prevent the disease. For individuals ineligible for vaccination, health insurance
covers the prevention of severe disease through an intramuscular injection of human
immunoglobulin within six days of exposure. The most important measure is prophylaxis prior to
exposure to the measles virus.
