Figure 2. A nucleocapsid vaccine improves the control of SARS-CoV-2 infection.

(A) Representative FACS plots showing the frequencies of SARS-CoV-2 nucleocapsid–specific CD8⁺ T cells (D^bN219⁺) in PBMCs. (B) Summary of SARS-CoV-2 nucleocapsid–specific antibodies in sera. (C) Weight loss following infection. (D) Viral loads in lungs on day 5 after infection. K18-hACE2 mice were primed intramuscularly with Ad5-N, and after 2 weeks adaptive immune responses were evaluated, and mice were challenged intranasally with 5 × 10⁴ PFU of SARS-CoV-2. Viral RNA was quantified by RT-qPCR. Challenges were performed with a total of 5 mice per group in BSL-3 facilities. P values were calculated using a Mann-Whitney U test. Error bars represent the SEM.