Figure 2.

Viral RNA levels in the upper respiratory tract of RMs after SARS-CoV-2 challenge

RMs (3–11 years old) were immunized via intranasal route with ChAd-Control or ChAd-SARS-CoV-2-S. Four weeks later, RMs were challenged with 1 × 10⁶ 50% tissue culture infective dose (TCID₅₀) of SARS-CoV-2 (strain 2019 n-CoV/USA_WA1/2020) split between the intranasal and intrabronchial administration routes.

(A) Clinical scores after challenge. Boxes show the 25th–75th percentiles, the center lines represent the median, and the extended whiskers from boxes indicate the minimum/maximum values.

(B–E) Nasal swabs were collected at days +1, +3, +5, and +7. Viral RNA was measured by qRT-PCR using primers specific for subgenomic mRNA (N gene) (B and D) or genomic RNA (nsp12 gene) (C and E) (n = 6, Mann-Whitney test: ∗p < 0.05; ∗∗p < 0.01; ns, not significant). (D and E) Longitudinal analysis of SARS-CoV-2 viral RNA in nasal swabs as determined by qRT-PCR showing the subgenomic (D) and genomic RNA (E). Each connected line shows the viral RNA in individual animals at the indicated time points.

(F) Levels of infectious virus (TCID₅₀ analysis) recovered from nasal swabs of RM obtained 1 day after SARS-CoV-2 challenge (n = 6, Mann-Whitney test). Column heights (B, C, and F) indicate median values. The dotted line represents the LOD of the assay in this figure.

See also Table S1.