Increased transmissibility explains the third wave of infection by the 2009 H1N1 pandemic virus in England

摘要: In the 2009 H1N1 pandemic, United Kingdom experienced two waves of infection, first in late spring and second autumn. Given low level susceptibility to pandemic virus expected be remaining population after wave, it was a surprise that substantial third epidemic occurred UK between November 2010 February 2011, despite no evidence for any significant antigenic evolution virus. Here, we use mathematical model influenza transmission embedded within Bayesian synthesis inferential framework jointly analyze syndromic, virological, serological surveillance data collected England 2009–2011 thereby assess epidemiological mechanisms which might have generated wave. We find substantially increased transmissibility H1N1pdm09 is required reproduce suggesting evolved fitness human host by end 2010, or very cold weather at time enhanced rates. also some preexisting heterologous immunity reduced attack rates adults during had decayed winter thus increasing adult infection. Finally, our analysis suggests vaccination campaign targeting school-age children could mitigated prevented wave even moderate levels coverage.