By Dan Vergano

Still above epidemic levels, the flu has peaked in hospital reports and lab tests nationwide, according to federal health officials.

"The geographic spread of influenza in Puerto Rico and 48 states was reported as widespread" as of Feb. 17, the Centers for Disease Control and Prevention said on Friday. Another 13 young children under the age of 5 died in that week of the flu, bringing the season's total to 97 infant deaths.

While the most active and dangerous strain of the flu, H3N2, remained the most reported strain seen in lab results, its incidence has steadily declined in the last five weeks, officials said. The less dangerous influenza type B strain is increasing, however, and hospitalizations increased in the last week.A CDC report last week found the 2017–18 flu vaccine was about 36% effective against the virus. Health officials have still urged people to still get a vaccination, however, both because of the limited protection it does offer and because it limits symptom severity in those infected.

The flu season is in its 13th week of high activity, during which 3,600 died of flu and associated illnesses — largely pneumonia striking people older than 50 — a 26% decline from the week before.