A next-generation intranasal trivalent MMS vaccine induces durable and broad protection against SARS-CoV-2 variants of concern
There is an urgent need to develop a mucosal SARS-CoV-2 vaccine that can induce broad, durable protection. MMR has been one of the safest and most successful vaccines in human history. By expressing the six-proline-stabilized prefusion spikes from three diverse SARS-CoV-2 strains in the MeV, MuV-JL1, and MuV-JL2 vaccine strains from MMR, we generated a MMS trivalent vaccine candidate. Intranasally delivered MMS induced strong SARS-CoV-2-specific neutralizing antibody, mucosal IgA, and systemic and lung resident T cell immune responses that provide broad protection against challenge with each of these three strains. Therefore, MMS is a highly promising next-generation vaccine candidate against COVID-19. Furthermore, any of the three component vaccine viruses can be quickly modified when a new important SARS-CoV-2 variant appears.