Experts are warning of a major outbreak of rubella, or German measles, in Japan this year, with more than 300 cases of infection already reported this year.
According to health authorities across the country, the number of rubella cases totaled more than 2,900 last year. That was the second-highest number in about a decade.
As of February 3 this year, 367 cases of rubella were reported. More than 60 percent of them were in Tokyo and surrounding prefectures.
If women catch rubella during pregnancy, their babies could be born with visual, hearing or cardiac disorders.
Last month, a baby boy in Saitama Prefecture outside Tokyo was diagnosed with congenital rubella syndrome.
According to the National Institute of Infectious Diseases, a rubella epidemic tends to last for several years, and a major outbreak is anticipated and more cases may follow. The institute advises women to get two vaccinations before their pregnancy.
The government is supplying the vaccinations free of charge.
In December, the government decided to launch a three-year program of giving free vaccinations in principle to men aged from 39 to 56. The group did not receive rubella vaccinations in their childhood and represented the largest portion of cases reported last year.