Rwanda has been so successful at fighting measles that next month it will be the first country to get donor support to move to the next stage — fighting rubella too.

On March 11, it will hold a nationwide three-day vaccination campaign with a combined measles-rubella vaccine, hoping to reach nearly five million children up to age 14. It will then integrate the dual vaccine into its national health service.

Rwanda can do so “because they’ve done such a good job on measles,” said Christine McNab, a spokeswoman for the Measles and Rubella Initiative. M.R.I. helped pay for previous vaccination campaigns in the country and the GAVI Alliance is helping to finance the upcoming one.

Rubella, also called German measles, causes a rash that is very similar to the measles rash, making it hard for health workers to tell the difference.