Preclinical efficacy, safety and immunogenicity assessment of a vaccine candidate in a cynomolgus monkey model of SARS-CoV-2 infection.
Joachim Confais (1), Marion Toussenot (1), Stéphane Ployart (1), Gregori Bech-Sabat (2), Mercè Roca (2), Andrés Pizzorno (3), Thomas Julien (4), Manuel Rosa-Calatrava (3), (4), Ricard March (2), Hugues Contamin (1)
(1) Cynbiose, 1 av. Bourgelat, 69280 Marcy-l’Étoile, France
(2) CIRI, Centre International de Recherche en Infectiologie, Team VirPath, Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007 Lyon, France
(3) HIPRA, Avda. La Selva, 135, 17170 Amer (Girona), Spain
(4) VirNext, Faculté de Médecine RTH Laennec, Université Claude Bernard Lyon 1, Université de Lyon, 69008 Lyon, France
Cynbiose, in collaboration with the laboratory VirPath, successfully developed a monkey model of SARS-CoV-2 infection, first in the African Green Monkey (2020), then in the Cynomolgus macaque (2021). HIPRA has developed an adjuvanted vaccine candidate, PHH-1V, based on a recombinant fusion heterodimer protein consisting of the RBD domain of the beta and alpha SARS-CoV-2 variants. A challenge study in cynomolgus macaques (Macaca fascicularis) was conducted to assess the efficacy, immunogenicity and safety of a prime-boost immunization scheme with the PHH-1V vaccine. Twelve cynomolgus monkeys were inoculated with a D614G variant of SARS-CoV-2. Prior to this, 6 of these animals were vaccinated twice with PHH-1V, and 6 with PBS (control animals). The vaccine was well tolerated, with no evidence of side effects. A 6-days follow-up of the animals after their infection clearly showed that the vaccinated animals had less viral copies and virtually no infectious virus in the upper or lower airways, compared to the control animals. Histopathological analysis of the lungs showed an overall decreased inflammation in the vaccinated animals. Finally, all vaccinated animals showed a strong neutralizing antibody response against 4 different strains of SARS-CoV-2. In conclusion, Cynbiose and VirPath/VirNext cynomolgus model of SARS-CoV-2 infection demonstrated the safety, immunogenicity and protective efficacy of Hipra’s PHH-1V vaccine.