Evaluation of mRNA-1273 against SARS-CoV-2 B.1.351 Infection in Nonhuman Primates.

BACKGROUND

Vaccine efficacy against the B.1.351 variant following mRNA-1273 vaccination in humans has not been determined. Nonhuman primates (NHP) are a useful model for demonstrating whether mRNA-1273 mediates protection against B.1.351.

METHODS

Nonhuman primates received 30 or 100 µg of mRNA-1273 as a prime-boost vaccine at 0 and 4 weeks, a single immunization of 30 µg at week 0, or no vaccine. Antibody and T cell responses were assessed in blood, bronchioalveolar lavages (BAL), and nasal washes. Viral replication in BAL and nasal swabs were determined by qRT-PCR for sgRNA, and histopathology and viral antigen quantification were performed on lung tissue post-challenge.

RESULTS

Eight weeks post-boost, 100 µg x2 of mRNA-1273 induced reciprocal ID

CONCLUSIONS

Immunization with two doses of mRNA-1273 achieves effective immunity that rapidly controls lower and upper airway viral replication against the B.1.351 variant in NHP.