Selection analyses were done based on datasets without putative recombinant sequences because recombination can result in falsely identifying positive selection [79] . The datasets were split into a vaccine-related group, which included strains from genotypes I and II, and nonvaccine-related group, which included strains from genotypes III, IV, V, VI, VII (see Table S2 ). Positively selected codons were detected using Fixed-Effect Likelihood (FEL) via the Datamonkey website (http://www.datamonkey.org/) and ML approach implemented in CODEML (PAML package version 3.15) [80] . For FEL analysis, p-values less than 0.05 were used to support positive selection. For PAML analysis, the likelihood ratio test was used to compare M1a, M7 and M8a models that assume no positive selection (v,1) with those M2a and M8 models that assume positive selection (v.1) [81] .  China's Engagement with Global Health Diplomacy: Was SARS a Watershed? As part of the PLoS Medicine series on Global Health Diplomacy, Lai-Han Chan and colleagues provide a case study of China's growing engagement in global health diplomacy following the SARS epidemic. This article is part of the PLoS Medicine Global Health Diplomacy series.