The Nebraska Department of Health is urging some campers to get a mumps booster shot.
The move comes after a counselor at Carol Joy Holling Camp near Ashland, who has a confirmed case of mumps, exposed other counselors at the camp.
State Epidemiologist Dr. Tom Safranek says a third MMR booster has been used before during specific outbreaks.
Children do not have to have a third booster, but those who were never vaccinated for mumps cannot attend the camp, until they receive the immunization.
The recent mumps outbreak began at Midland University and now totals 24 confirmed cases.