Fig. 5. Viral loads in lungs of immunized mice.
a Detection of N-specific immunity in vaccinated mice (6 mice per group). A total of 105 PBMCs were incubated overnight with or without 5 μg/ml of either unrelated or SARS-CoV-2-N-specific peptides in IFN-γ EliSpot microwells. Shown are the numbers of SFUs/well calculated as mean values of triplicates after subtraction of mean spot numbers detected in wells of PBMCs treated with an unspecific peptide. Reported is intragroup mean value. Two-tailed Mann–Whitney U Test p < 0.05, error bars, s.e.m. b Viral loads in lungs of immunized/infected mice. Four and six days after challenges, injected mice (6 per group) were sacrificed, and lungs processed for the extraction of total RNA. One μg of total RNA from each infected mouse was then analyzed by RT-qPCR for the presence of SARS-CoV-2 N-specific RNAs. As internal control, actin RNA was also amplified. Shown are the N viral RNA copies amplified from total RNA isolated from lungs of each animal, together with intragroup mean values. two-tailed Mann–Whitney U Test p: 0.0022, error bars, s.e.m. c Graph of the two-tailed Spearman Rank Correlation Test showing the inverse correlation between pre-existing N-specific CD8+ T cells and viral loads in lungs of immunized/infected mice.