Modeling shows that even the same virulence in more people this fall will result in higher fatality (by a factor of 3-5) compared to seasonal flu. The population becoming ill is different than seasonal flu (it's younger) and this is leading to a change of plans regarding vaccine strategy.
Evidence to date suggests that population immunity to this virus is low, particularly among the young. In one small serologic study of samples collected during 2006-08, cross-reacting antibody were found among some older persons but not in any younger adults or children. Widespread susceptibility to this virus among young persons creates the potential for large numbers of cases with more hospitalizations and deaths among younger age groups than would be expected for a typical routine seasonal influenza virus. Importantly, severe disease and death caused by novel H1N1 thus far have affected younger adults, children, and pregnant women, in addition to persons of all ages with certain underlying medical conditions more than the elderly. The virus has also caused numerous outbreaks in schools and summer camps.
Vaccine won't be available right away, and when it is, the high risk groups that will be targeted will change form the norm:
The following are best-case planning scenarios that would be recommended in a setting of limited initial vaccine availability.
"I want to be clear: This summit is not about raising alarms or stoking fears. It is about being prepared," Health and Human Services Secretary Kathleen Sebelius said. "We must avoid complacency."
We'll have more coverage of the summit when it's done, but this appears to be a gearing up of the public messaging on the part of the Feds, including an invitation to make a video public service announcement. Readers here will be familiar with the issues. Today, we get some of the details. And keep an ear open for the vaccine strategies before the fall. If the decision is made to vaccinate, it will be a separate shot (or two, still to be determined) from the regular seasonal flu jab, and will need to be offered in a variety of venues (schools, doctor offices, special flu clinics, etc.) Whatever the final plan, it won't be business as usual.