A weekend was lost, but for Karissa Loper, it was nothing compared with the knowledge gained.

Loper is now a program manager for the Nevada State Immunization Program. Then, she was just a college student who thought flu vaccines were for someone else.

“I just ignored it,” she says. “It wasn’t like I was against it or anything. My whole crew that I hung out with, none of us were in health-related fields of study. So no one really even talked about it.”

It took just one weekend for that to change for Loper.

“I remember on that Thursday, I woke up and I felt pretty cruddy, but I didn’t think it was anything serious, so I went to class,”Loper says. “But Friday, I felt just awful. It was really, really bad.

Loper says she dragged herself to the student health center, was tested for flu, given antivirals and told to go home and not do anything.

That last bit of advice wasn’t really necessary. “I literally stayed in bed the whole weekend,” she says. “My friends had plans. But I didn’t want to move at all.”

It’s a familiar story, played out across the country. A University of Buffalo study in 2010 found just 8 percent of college-age respondents had been vaccinated.

While the risk of life-threatening complications is lower than for young children and seniors, the flu packs a punch that often comes as a surprise to young adults.

“The flu really knocks you down,” says Dr. Andy Pasternak of Silver Sage Center for Family Medicine in Reno. “You can be laid out for two or three weeks. It affects your studies, your athletic fitness.”

The lifestyle of younger adults puts them at specific risk of spreading the disease. They generally live and socialize more in groups and, as Pasternak says, it just takes one person to infect the group.

“People in that age group tend to burn the candle at both ends,” he says. “They study hard, they play hard and may not be getting as much sleep as they should. Those things can compromise the immune system.”

Loper was lucky in a few respects. She had easy access to a student health center, she caught it early enough to avoid hospitalization and recovered in less than a week. The experience, however, was enough to change her outlook. She became diligent about getting her shots.

And her crew? “They get their shots,” Loper says. “We didn’t have to talk about it. They saw what happened to me.”