CD4 and susceptibility to pneumonia measurement: Vector was shown to protect rhesus macaques against six strains of MERS-CoV.Early phase I/II clinical trial data show that vaccine was well tolerated and induced humoral and cell-mediated responses.Vaccine was found to induce robust humoral, CD8 and Th1 dominated CD4 responses in mice and rhesus macaques, and that both a prime and prime-boost regimen protected rhesus macaques against COVID-19 related pneumonia.Entered phase III clinical trials in August 2020