RESUMEN
A combination of vaccination approaches will likely be necessary to fully control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Here, we show that modified vaccinia Ankara (MVA) vectors expressing membrane-anchored pre-fusion stabilized spike (MVA/S) but not secreted S1 induced strong neutralizing antibody responses against SARS-CoV-2 in mice. In macaques, the MVA/S vaccination induced strong neutralizing antibodies and CD8+ T cell responses, and conferred protection from SARS-CoV-2 infection and virus replication in the lungs as early as day 2 following intranasal and intratracheal challenge. Single-cell RNA sequencing analysis of lung cells on day 4 after infection revealed that MVA/S vaccination also protected macaques from infection-induced inflammation and B cell abnormalities and lowered induction of interferon-stimulated genes. These results demonstrate that MVA/S vaccination induces neutralizing antibodies and CD8+ T cells in the blood and lungs and is a potential vaccine candidate for SARS-CoV-2.
Asunto(s)
Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , Vectores Genéticos/genética , SARS-CoV-2/inmunología , Vacunas de ADN/inmunología , Virus Vaccinia/genética , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Antígenos Virales/genética , Antígenos Virales/inmunología , COVID-19/inmunología , COVID-19/patología , COVID-19/virología , Vacunas contra la COVID-19/genética , Modelos Animales de Enfermedad , Expresión Génica , Orden Génico , Inmunofenotipificación , Pulmón/inmunología , Pulmón/patología , Pulmón/virología , Macaca , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patología , Ratones , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Vacunación/métodos , Vacunas de ADN/genéticaRESUMEN
There is a great need for the development of vaccines that induce potent and long-lasting protective immunity against SARS-CoV-2. Multimeric display of the antigen combined with potent adjuvant can enhance the potency and longevity of the antibody response. The receptor binding domain (RBD) of the spike protein is a primary target of neutralizing antibodies. Here, we developed a trimeric form of the RBD and show that it induces a potent neutralizing antibody response against live virus with diverse effector functions and provides protection against SARS-CoV-2 challenge in mice and rhesus macaques. The trimeric form induces higher neutralizing antibody titer compared to monomer with as low as 1µg antigen dose. In mice, adjuvanting the protein with a TLR7/8 agonist formulation alum-3M-052 induces 100-fold higher neutralizing antibody titer and superior protection from infection compared to alum. SARS-CoV-2 infection causes significant loss of innate cells and pathology in the lung, and vaccination protects from changes in innate cells and lung pathology. These results demonstrate RBD trimer protein as a suitable candidate for vaccine against SARS-CoV-2.