Young people most vulnerable to this year's flu strain

This year's strain of the flu is affecting young people more than ever, the Centers for Disease Control and Prevention reported Thursday.

People ages 18 to 64 comprise 61 percent of all influenza-related hospitalizations recorded during the current flu season - a significant increase for the demographic when compared to past years' 35 percent. Health officials note that it's highly unusual that more flu-related deaths are occurring in the under 65-age group, with more than half this season occurring in adults between 25 and 64, compared to less than a quarter last year.

The CDC stresses the importance of vaccines, especially given that only 40 to 45 percent of Americans are vaccinated each year.

"Influenza can make anyone very sick, very fast and it can kill," said the CDC's director, Dr. Tom Frieden, according to CNN. "Vaccination every season is the single most important thing you can do to protect yourself."

He added that only a third of people 18 to 64 had been vaccinated by November.

H1N1 dominating flu cases

The CDC's Morbidity and Mortality Weekly Report noted that this year's flu vaccine reduces the chance of having to go to the doctor for treatment by about 60 percent across all age groups. In past years, the vaccine's effectiveness has ranged from 30 to 65 percent.

"We are committed to the development of better flu vaccines, but existing flu vaccines are the best preventive tool available now," Frieden said.

The CDC estimates that between 3,000 and 49,000 people die annually because of the flu and flu-related illness. As of Feb.14, there were 243 reported deaths, with the number of severe cases higher even than those during the H1N1 outbreak.

"The 405 reports of severe cases (i.e., fatal and ICU cases combined) were more than in any season since the 2009 pandemic," officials wrote in the MMWR.

Experts expect continued heightened flu activity for the rest of the season.

"I want to remind you that the season is not over," said Dr. Anne Schuchat, director of the National Center for Immunization and Respiratory Diseases. "There is still a lot of influenza circulating. If you haven't been vaccinated yet, it's not too late for you to benefit."