Fig. 5: Relative humidity has no effect on SARS-CoV-2 transmission via droplets.
From: Survival and transmission fitness of SARS-CoV-2 over the time-of-flight in an aerosolization chamber
106 IUs of VSV-GFP or SARS-CoV-2, including USA-WA1/2020, Delta, and Omicron, were aerosolized at 18 °C–25 °C at different relative humidity (RH) ranges. Droplets were collected on rice paper from the top and bottom trays. Under 18 °C–25 °C and 40% < RH < 60%, the estimated volume collected was 7.9 × 10-4 μL for the top tray and 3.8 × 10-4 μL for the bottom tray. a, b Quantification of infectious USA-WA1/2020 recovered from rice paper. c, d Quantification of infectious VSV-GFP recovered from rice paper when aerosolized at 25 °C with varying RH levels. e, f Comparison of virus recovery from rice paper when SARS-CoV-2 or VSV was aerosolized under extreme environmental conditions (cold at 4 °C, or hot at 36 °C and dry RH < 50% or humid RH > 70%). g, h Comparison of SARS-CoV-2 strains recovered from rice paper when aerosolized under 60% < RH < 70%. Statistical significance in (a–d, g, h) was determined using the Kruskal-Wallis test followed by Dunn’s multiple comparisons test or the two-tailed Mann-Whitney test (e and f). Two-tailed Pearson correlation analysis was performed in (c, d) to evaluate the relationship between the quantity of recovered infectious virus (TCID50/mL) and RH. *, P < 0.05; **, P < 0.01. The dotted line indicates the lower limit of detection (6.61 TCID50/mL). Each data point was from one aerosolization. Geometric mean is shown.
