Laboratory testing has confirmed a fifth case of measles in Clallam County this year, county health officials said today, Friday, March 13.

The case is an adult relative of two earlier cases who was thought to be immune to measles.

This latest case was exposed to one of the earlier cases during their infectious period.

A total of five cases of measles have been confirmed in Clallam County since February. The first four cases occurred among individuals who were not vaccinated against measles. The fifth and newest case had received one dose of measles vaccine in the 1970s. The vaccine that was in use at the time had a different formulation from the current vaccine and was less effective, health officials said today.

According to Dr. Jeanette Stehr-Green, Clallam County Health Officer, about 95 percent of people who receive one dose of the current measles vaccine are protected against measles. The percentage increases to 97-99 percent following two doses.

Current recommendations are that children should be vaccinated with two doses of measles, mumps, and rubella vaccine with the first dose typically being given between 12-15 months and the second at 4-6 years. Adults who have not had measles and were born after 1956 should have at least one measles vaccination. Some people need two, such as health care workers.

No-cost MMR vaccination clinics will be held at HHS Public Health Section, 111 E. Third St., Port Angeles, on the following dates:

• March 16, 8:30 a.m.-4 p.m., walk-in clinic

• March 19, 8:30 a.m.-4 p.m., appointments or walk-ins accepted

• March 21, 10 a.m.-2 p.m., walk-in clinic

Appointments may be made for any of the clinics by calling 360-417-2274.