The viability of viruses in aerosols and droplets is also affected by environmental factors, such as temperature [21, 22], humidity [16–18, 23–27], and ultraviolet radiation [28–30]. Temperature and ultraviolet radiation primarily affect the viability of viruses by destroying their structural integrity [31]. Other studies have shown that the viability of viruses in both aerosols and droplets depends on relative humidity (RH) [18, 26, 27]. Our previous studies have reported a U-shaped pattern in virus viability as a function of RH in both aerosols and droplets; viruses survived well at RHs lower than 40% or near 100%, but their viability was reduced at intermediate RH [13, 18]. We have proposed that this relationship is mediated by changes in the physicochemical properties of aerosols and droplets as they evaporate to equilibrate with ambient RH [10, 32]. To our best knowledge, there have not been any studies that explore the interaction effects of media composition and relative humidity on virus survival in droplets.