To our best knowledge, the effect of the chemical composition of droplets on the transmission of human or mammalian viruses has not been reported previously. Our results with model bacteriophages indicate that their survival in droplets is sensitive to the concentrations of different components in the droplets. This observation agrees with the findings from a previous study that investigated the effects of salt and protein on the survival of influenza virus in droplets; high salt concentrations were correlated with greater virus inactivation while protein protected the virus [17]. Since viruses must retain their infectivity to transmit successfully, our results imply that the chemical composition of droplets may influence virus transmission by modulating the survival of viruses.