Figure 3. Aerodynamic particle analysis of SARS-CoV-2 infected hamsters.

(A) Syrian hamsters were inoculated with 10³ TCID₅₀ via the intranasal route with Alpha or Delta. Aerodynamic diameter profile of exhaled particles was analyzed on days 0, 1, 3, and 5. Heatmap shows rounded median percent of total particles across groups, including the anesthesia control group (N=10, comprising five males and five5 females). Colors refer to scale below. (B) For each animal, line graphs of the percent of particles in the <0.53 and 1–10 µm diameter range by variant group and sex indicated by color. Multiple linear regression performed for each diameter range with group and sex as predictors, F-statistic (Boone and Gerba, 2007; Jones et al., 2021)=9.47 for<0.53 µm model and F-statistic (Boone and Gerba, 2007; Jones et al., 2021)=2.62 for 1–10 µm model, with Tukey multiple comparison adjustment for the three variant-group comparisons (95% family-wise confidence level). For <0.53 range, Male-Female (estimate = –1.7, standard error = 0.888, two-sided p=0.0659); Alpha-Control (estimate = 2.41, standard error = 1.09, two-sided p=0.0874), Delta-Control (estimate = 5.40, standard error = 1.09, two-sided p=0.0001), Delta-Alpha (estimate = 2.99, standard error = 1.09, two-sided p=0.0280). For 1–10 range, Male-Female (estimate = 2.19, standard error = 1.23, two-sided p=0.0875); Alpha-Control (estimate = –0.633, standard error = 1.51, two-sided p=0.9079), Delta-Control (estimate = –3.098, standard error = 1.51, two-sided p=0.1197), Delta-Alpha (estimate = –2.465, standard error = 1.51, two-sided p=0.2498). Grey = Alpha, teal = Delta, beige = anesthesia control, red = female, blue = male.

Figure 3—figure supplement 1. Exhaled particle profiles of Syrian hamsters.

(A) Chambers used to house uninfected hamsters (left) and animals during inoculation experiments (inoculation with Alpha, Delta or control inoculum) (right).(B) Uninfected healthy animals were used to assess particle profiles in relation to behavior patterns. Five Syrian hamsters were acclimatized to a small tube, in which animal movement was limited and air flow was directly passing the face. For each animal, 5x5 min readings were taken. Heatmap shows the percentage of total particles in each diameter size for three male and two female animals. * marks minutes of low to no activity (sleep). Colors refer to scale below. (C). Syrian hamsters were inoculated with 10³ TCID₅₀ via the intranasal route with Alpha (N=10) or Delta (N=10). Aerodynamic diameter profile of exhaled particles was analyzed on days 0, 1, 3, and 5. For each animal (N=10 in each variant group, comprising five males and five females), line graph of the total number of particles by variant and sex indicated by color (red = female; blue = male).