Pandemic (H1N1) 2009 Virus in 3 Wildlife Species, San Diego, California, USA

Abstract

When the fi rst patients with ILI in households were unvaccinated, ILI was observed in 59 of 136 children, yielding an SAR b0 of 43.4%. Among 6 exposures caused by vaccinated fi rst patients, ILI developed in 1 person, yielding an SAR b1 of 16.7%. Although not signifi cant (p = 0.40), the reduction in infectiousness by vaccination was estimated to be 1 -SAR b1 /SAR b0 = 61.6% (95% CI -132.3% to 93.6%). The SAR 01 was 0% (i.e., 1 exposure to an unvaccinated person caused by a vaccinated fi rst patient did not result in infl uenza). Limiting the defi nition of infl uenza to confi rmed cases, all 8 exposures to vaccinated persons did not result in infl uenza, and SAR 0b and SAR 1b were 10.8% and 0%, respectively. Similarly, all 5 exposures caused by vaccinated fi rst patients did not result in confi rmed cases, and SAR b0 and SAR b1 were 10.5% and 0%, respectively.