The public health policy implications of understanding metabiosis.

In this issue of Cell Host & Microbe, Siegel et al. (2014) report that colonization of Streptococcus pneumoniae is facilitated by coinfection with influenza virus through utilization of sialic acids cleaved by the viral neuraminidase. The implications of this finding for use of influenza antivirals to prevent flu-related complications are discussed.