TEMPLE, Texas (CBSDFW.COM) — Texas flu patients are playing a role in making the vaccine more effective.

With a grant from the U.S. Centers for Disease Control and Prevention, Dr. Manjusha Gaglani operates one of five study sites across the country for the U.S. Influenza Vaccine Effectiveness Network.

As a pediatric infectious disease specialist at Baylor Scott & White in Temple, she helped author the study showing the vaccine performed well this season with a 55% effectiveness rate in children.

“If you’re vaccinated, your chance of seeing your doctor for a flu illness is reduced by half,” Dr. Gaglani explained.

Still, every year, she finds patients like Robert Krepps, who tested positive for the virus at an urgent care clinic in Killeen despite getting his flu shot.

“It’s a huge… big surprise,” he said.

The vaccine can fail, Gaglani says, because of the virus is constantly mutating.

Health organizations are trying to keep up, using research like hers to help determine the formula for next season’s flu shot.

Nurses take nose and throat swabs from consenting patients like Krepps.

Dainarra Foster, a medical assistant who helps collect the samples, says few patients decline to take part.

“The research aspect of being part of something bigger is always great,” Foster said.

From the swabs, lab technicians isolate the virus and send it to the CDC, where it’s compared against the current vaccine.

“There’s been a good match,” said Dr. Gaglani of this year’s results.

The biggest obstacle may be in convincing people to get the shot. Fewer than half of all Texans do.

And this year, the virus got an early start this year with a strain children are particularly susceptible to.

“There are a lot of unvaccinated young children. That’s how the flu B took off,” she said.

Krepps may be healthy enough to quickly recover, but his mother, Ann Rowe, is a cancer survivor, who doesn’t take good health for granted.

“Maybe it’ll help somewhere down the line, and I hope it does,” she said.