Lois Simpson pulled up the sleeve of her red and white Terps sweatshirt and grimaced as the nurse quickly jabbed her arm.

"I'm a chicken," said the University of Maryland freshman, gingerly holding the arm in which she had just received a measles vaccination. But she added that news of a measles outbreak that has been infecting campuses across the country had overcome her natural aversion to needles.

"I'd rather live than die," said Simpson, who was among 675 University of Maryland students and staff who voluntarily -- if not eagerly -- trooped to a makeshift vaccination center in the student union to receive free measles shots from the Prince George's County Health Department.

"Well, we gave a party and people are coming," said Dr. Margaret Bridwell, director of health services at the 38,000-student College Park campus. "We were nervous no one would show up."

But Prince George's health officials who brought 500 doses of the vaccine had to send for a reserve supply of 200 to accommodate all those seeking shots.

College-age students are particularly susceptible to measles, which many health officials consider the most serious of the common childhood diseases, because they grew up during a period when the disease was on the decline but before completely effective vaccines came into widespread use.

Relatively few college-age people contracted the disease while children, which would have given them an immunity to it, Bridwell said.

Measles experts at the national Centers for Disease Control in Atlanta estimate that between 5 and 15 percent of young adults are not protected against the highly contagious virus.

The most serious recent outbreaks have been reported at Boston University, where 55 students were stricken before spring break started March 2, and at Principia College, a Christian Science school in Elsah, Ill., where 100 students have come down with measles and three have died of complications.

No cases of measles have been reported in the Washington area, although the Virginia Department of Health is currently investigating a suspected case in an Alexandria preschooler.

At the University of Maryland, officials moved up a vaccination day planned for later this year to inoculate students before they leave for spring break and come into contact with students from other colleges who might be carrying the disease.

"Say the student from Boston and the student from the University of Maryland meet down in Florida on spring break," said Robert A. Sparks, chief of communicable disease control for the Prince George's County Health Department.

"They could expose each other down there and then bring it back here. All it takes is one or two students to spread it," said Sparks, who spent the day filling needles as fast as the nurses could empty them.

Doctors at the Centers for Disease Control have urged colleges to require students to show proof that they have been vaccinated against measles, as Boston University has done; the medical officials criticized voluntary plans like that at the University of Maryland as inadequate protection against an outbreak.

"When you have a voluntary vaccination it doesn't really control an outbreak," said Dr. John Frank, a medical epidemiologist at the national centers. "The people who wouldn't have been vaccinated before probably won't come. The ones who have had three or four vaccinations in the past probably are the ones who will show up."

But health services director Bridwell said that requiring student vaccinations was too burdensome in the absence of any cases. "If you get one case, you clamp the lid on and get everybody," she said.

Steven August, a junior business major from North Woodmere, N.Y., said he thought he had already been vaccinated but decided to take extra precautions before his spring break trip to Fort Lauderdale. "I don't want to take any chances," said August, noting that his girlfriend attends Boston University.

"This reminds me of being young again," said Marc Hurwitz, a graduate student in physics from Toronto, as he held out his arm for the shot. "Where's my lollipop?" he asked county health nurse Charlotte Stagg.