A Sars Coronavirus Vaccine, A Double-Inactivated Whole Virus Candidate, Produces Protective and Negative Antibody Responses

Abstract

Using fermenter cultures of serum protein-free Vero cells, a double-inactivated candidate whole virus vaccine against the severe acute respiratory syndrome associated coronavirus (SARS-CoV) was developed and produced on a large scale. To provide a very high safety margin with regard to residual infectivity, a two-step inactivation process that involves successive formaldehyde and UV inactivation was used. This double-inactivated vaccine's immunogenicity has been tested using a mouse model. Mice that given two doses of the proposed SARS-CoV vaccine showed high levels of neutralizing antibodies and antibody titres against the SARS-CoV spike protein. Only a small adverse effect on the vaccine's immunogenicity was caused by the addition of the adjuvant Al (OH)3. In addition, immunization induced cell-mediated immunity as demonstrated by interleukin-4 and interferon stimulation. Additionally, the vaccination gives protective immunity, wherein shown by stopping SARS-CoV multiplication in the mice's respiratory tracts following an intranasal SARS-CoV challenge. Antibody titres against the SARS-CoV S protein and neutralizing antibody titres were linked to mice's protection.