This is today's must-read, and it will absolutely be on the final exam. Via the New England Journal of Medicine: Managing and Reducing Uncertainty in an Emerging Influenza Pandemic. Excerpt:
Paradoxically, uncertainty about this infection's characteristics is likely to increase further as the Northern Hemisphere's summer progresses. The low specificity of clinical signs and symptoms, combined with changes in reporting practices, will make it difficult to interpret apparent incidence trends at the national level.
Without reliable incidence measures, it is impossible to track the epidemic's growth rate, which makes estimates of transmissibility highly uncertain and subject to biases because of changes in the probability of detection. School absences, a crude measure of epidemic spread, will become less informative once most schools are closed for the summer.
Without good incidence estimates, estimates of severity will continue to suffer from an uncertain denominator. The effectiveness of control measures will be difficult to assess without accurate measures of local incidence.
When a vaccine becomes available, appropriate targeting of limited supplies will require knowledge of levels of preexisting immunity, age-specific severity estimates, and other quantities that depend on reliable measures of the incidence of mild and severe disease.
If we could be sure that the infection would remain mild in most cases, these uncertainties would be similar to those we tolerate in a normal influenza season, although the numbers affected would probably be larger.
But historically, pandemic viruses have evolved between seasons, and the current strain may become more severe or transmissible in the coming months.
Thus, decision makers in both hemispheres could again face uncertainty about the characteristics of a possibly evolving virus in the coming half-year.
There is a brief window of opportunity to take measures to reduce the uncertainty.
Serologic studies in the tropics during the Northern Hemisphere summer and at higher latitudes in both hemispheres will permit estimation of the extent of spread of mild infection.
If transmission wanes in the north, a late-summer serologic survey will provide baseline information about population immunity that will aid in both vaccine targeting and interpretation of patterns of illness in the fall.
