Over-40s Have Immunity to Strain of Flu

Most Americans older than 40 have some immunity to this season’s dominant flu strain because they’ve had it before, the government said.

The Type-A Texas flu strain that is most common this season is the same flu that dominated from 1920 to 1957, the Centers for Disease Control and Prevention said.

In the 29 states where widespread flu outbreaks have been reported, Texas-A is more common than the season’s two other strains, A-Johannesburg and B-Beijing.

The Texas strain vanished for 20 years, then reemerged but caused relatively little illness. It disappeared again after 1989.

While it leaves many people weak, it is not especially deadly, said Nancy Arden, the CDC’s chief of influenza epidemiology.

The Type-A Texas flu is striking mostly children and younger adults, who are less likely to die from the flu. Many of the states where flu is widespread report outbreaks in schools, but few in nursing homes, Arden said.

Flu contributes to the deaths of about 20,000 people a year.

The CDC recommends vaccinations for people at high risk, including those 65 and older, nursing home residents, children with asthma and anyone with a chronic illness.