Usually, flu season strikes earlier. By this time last year, the
flu had been widespread and had already officially killed 34
people. The year before, the H1N1 pandemic disproportionately
sickened children and triggered a scramble for vaccine. Public
health officials say this is the nature of influenza. "Unlike
other respiratory viruses, flu is a little more unpredictable,"
said Dr. Trish M. Perl, professor of medicine, pathology and
epidemiology at the Johns Hopkins University and the senior
epidemiologist for the Hopkins Health System. "Flu activity is
just starting to pick up, and I can speculate as to why, but
really flu is just more variable." Maybe it has been slow this
year because of the warm weather, Perl said, but there's not a
lot of evidence to support that. Maybe people are not passing
the virus around because they're not cooped up inside. Maybe
some immunity has developed to the H3N2 and H1N1 strains that
have been circulating for the past couple of years. The first
case of laboratory-confirmed