Japan's health ministry has decided to give vaccinations for rubella, or German measles, free of charge to middle-aged men.
Ministry officials say more than 2,400 people have been infected with rubella this year in Japan. The figure is the most since a large outbreak in 2013.
About 2,000 of them are men, and most of those men are in their 30s to 50s and did not receive rubella vaccinations during childhood. It is said that about 20 percent of men in that generation are not fully immune to rubella.
To contain infection, the ministry has decided to test the men for antibodies and if they are found to not have any, it will inoculate them free of charge over about 3 years from 2019.
The ministry aims to eradicate infections by 2020 when many foreign visitors will be arriving in Japan for the Tokyo Olympic and Paralympic Games.
Rubella infections during pregnancy can result in visual, hearing or cardiac disorders in the baby.