Catching seasonal flu reduces future severity

Courtesy of Reuters Health

Immunity from previous cases of seasonal flu helped temper the severity of the pandemic flu that spread around the globe in 2009. Texas researchers monitored hundreds of adults through the 2009-2010 flu season and found that those who had seasonal flu in the past were less vulnerable to the pandemic H1N1 strain.

Researchers tracked 513 adults. Overall, 116 subjects were infected with H1N1 as determined by antibodies in their blood. Thirty-three percent of those who had no evidence of antibodies to the previous season's flu at baseline became infected with H1N1 - compared to 18% of those with antibodies to seasonal flu, according to the report in Clinical Infectious Diseases.