About 280 students at Roland Park Elementary-Middle School failed to show proof of a measles booster and were unable to attend classes as of yesterday, according to city health officials.
City health officials -- who have run four free vaccination clinics at the 1,700-student school since last week -- were to offer free boosters at the school once again today, from 1 to 5 p.m.
Students will be barred from the school unless they can show they have been immunized again against the disease while the outbreak is going on, said John Santelli, head of school and adolescent health for the city Health Department.
"They can't go to school unless they get their immunization," he said.
Two confirmed cases of measles have been reported at the school so far, said Santelli. The school was closed the week of March 31 for spring break, but students were told to return to classes last Monday with proof that they had received a second measles shot.
After extending the deadline until yesterday, city health officials began barring students from class if they had not received the second shot. Those students were kept separate from other students, either for the entire day or until parents could take them home.
To date, Roland Park, at 5207 Roland Ave., is the only city school to which the city has dispatched an emergency vaccination clinic.
There have been six actual cases of measles in city schools this year and five in Baltimore County schools, said Ed Hirshorn, assistant chief in the immunization division of the state health department. Cecil County, with 12 cases, has reported the worst outbreak in the state.
Anne Arundel and Howard counties were hit hard by measles in recent months, although the number of actual and suspected cases has dropped since booster shot programs were begun in those subdivisions, Hirshorn said.
"Students are required by state law to have one measles shot, but it's been shown that one is not quite enough," he said. "In a population group, 95 percent will be protected against measles with one shot. Still, that means that in a school with 1,000 kids, 50 will not be immune. The second shot gives 99 1/2 percent immunity."
Hirshorn advised parents of sixth-grade students to see that their children have been immunized twice against measles. Students of all ages should get a second shot if a suspected measles case has been reported at their schools.
Measles can be fatal or result in encephalitis, leading to convulsions, deafness or mental damage.