A review of hospital records revealed that, among children, H1N1 pandemic flu was not linked to hospitalization or pneumonia compared with either H1N1 seasonal flu or H3N2 seasonal flu.
Among children with H1N1 pandemic flu, 1.5 percent were hospitalized, as were 3.7 percent with H1N1 seasonal flu and 3.1 percent of those with H3N2 flu, the researchers found.
Among adults, 4 percent of those with H1N1 pandemic flu were hospitalized, as were 2.3 percent with H1N1 seasonal flu and 4.5 percent with H3N2 flu, they added.
As for pneumonia, 4 percent of adults with H1N1 pandemic flu came down with the condition, compared with 2.3 percent of those with H1N1 seasonal flu and 1.1 percent of those with H3N2 flu, Belongia's team found.
Among children, 2.5 percent of those with H1N1 pandemic flu developed pneumonia, as did 1.5 percent with H1N1 seasonal flu and 2 percent of those with H3N2 flu.
Influenza expert Dr. Marc Siegel, an associate professor of medicine at New York University in New York City, said that "this confirms what we were noticing from the beginning with H1N1, which is that, structurally, it was a mild virus."
As a mild virus it wasn't any more deadly, Siegel said. It had a predilection for the young and it was expected there would be more serious complications, but there weren't, he added.
Siegel said the virus attacked young people because they didn't have any immunity to it, which is typical with pandemic flu strains.
"Even though it was a mild virus, we didn't have immunity, so that made it somewhat unpredictable," Siegel said. "This study shows that despite our lack of immunity the complications were no greater than the yearly flu. That's a new finding."
This year, it is doubtful H1N1 pandemic flu will be noticed, Siegel said. In the first place, this year's flu vacci
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