Influenza claimed the life of a western Pennsylvania girl late last week, just as flu cases are continuing to rise.

Payton Pierson, 10, of Washington County died on Thursday at Children's Hospital of Pittsburgh. An aunt, Carissa Worobec, said she did not know if the girl had been vaccinated, according to

Pierson, a third grader, was diagnosed with the flu on Feb. 4 at Washington Hospital,  and then returned to her family's nearby home, the aunt said. The following Sunday morning, however, the girl collapsed and was taken back to the hospital, which then summoned an air ambulance to take her to Children's Hospital.

She remained in a coma until last Thursday, when she was removed from life support, said the aunt. Her funeral was held Monday.

There have been 20 child flu deaths nationally so far this season, according to the federal Centers for Disease Control and Prevention.

"Almost all of the children who die of influenza are not vaccinated," John Williams, chief of pediatric infectious disease at Children's Hospital of Pittsburgh told

By the end of flu season, an estimated 100 to 200 children under 18 years old will have died from complications from the flu, according to the federal centers. The flu kills over 30,000 people on the average annually.

Children and the elderly are considered to be most vulnerable.

About 46 percent of Americans received vaccines during the 2015-16 season, a 1.5 percent decrease from the previous season. Medical authorities recommend that most people over the age of 6 months receive an annual flu shot. Other preventive measures include frequent hand-washing, covering coughs, and staying home when you are ill.