A rubella outbreak is rapidly spreading in Japan.

Japan’s National Institute of Infectious Diseases announced that five-thousand-442 people came down with the disease between January and April 28th this year.

That is more than double the number of people who were infected with rubella in Japan over the course of 2012.

The institute advised people to immediately get vaccinated, noting that more than 500 people were infected by the disease each week in April.