THURSDAY, Sept. 18, 2014 (HealthDay News) -- Less than half of all Americans got a flu shot last year, so U.S. health officials on Thursday urged that everyone 6 months and older get vaccinated for the coming flu season.

"It's really unfortunate that half of Americans are not getting the protection from flu they could get," said Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, during a morning news conference.

The result is lost days from work and school and a lot of preventable suffering, hospitalizations and deaths, he said.

Just one-third of adults 18 to 64 -- the age group hit especially hard last flu season -- were vaccinated against flu last year, according to new CDC figures.

Also, more than 100 children died from flu-related complications last year, Frieden noted.

"Many of those deaths might have been prevented if children had gotten a flu vaccination," he said. Ninety percent of the children who died were unvaccinated, he added.

Dr. Paul Offit, a professor of pediatrics at the Children's Hospital of Philadelphia, said during the press briefing that every year children die in his hospital from flu.

"Parents' reaction is invariably the same," he said. "They can't believe this happened to them."

Most of these parents didn't want their child vaccinated because they didn't consider flu serious or they thought the vaccine wasn't safe, Offit said.

"The riskiest aspect of getting vaccines is driving to the office to get them," Offit said.

While just 46 percent of Americans overall were vaccinated against flu last year, children fared better than adults -- with 59 percent of kids immunized compared to 42 percent of adults, the CDC said.

Coverage was highest among children younger than 5 years and adults 65 and older, according to the CDC's Sept. 19 Morbidity and Mortality Weekly Report.

This year the CDC recommends the flu nasal spray vaccine for children 2 to 8 years old, Frieden said. But if the nasal spray isn't available immediately, these kids should get the shot, he said.