Safety and potency of BIV1‐CovIran inactivated vaccine candidate for SARS‐CoV‐2: A preclinical study

Abstract

Summary The development of effective and safe COVID‐19 vaccines is a major move forward in our global effort to control the SARS‐CoV‐2 pandemic. The aims of this study were (1) to develop an inactivated whole‐virus SARS‐CoV‐2 candidate vaccine named BIV1‐CovIran and (2) to determine the safety and potency of BIV1‐CovIran inactivated vaccine candidate against SARS‐CoV‐2. Infectious virus was isolated from nasopharyngeal swab specimen and propagated in Vero cells with clear cytopathic effects in a biosafety level‐3 facility using the World Health Organization’s laboratory biosafety guidance related to COVID‐19. After characterisation of viral seed stocks, the virus working seed was scaled‐up in Vero cells. After chemical inactivation and purification, it was formulated with alum adjuvant. Finally, different animal species were used to determine the toxicity and immunogenicity of the vaccine candidate. The study showed the safety profile in studied animals including guinea pig, rabbit, mice and monkeys. Immunisation at two different doses (3 or 5 μg per dose) elicited a high level of SARS‐CoV‐2 specific and neutralising antibodies in mice, rabbits and nonhuman primates. Rhesus macaques were immunised with the two‐dose schedule of 5 or 3 μg of the BIV1‐CovIran vaccine and showed highly efficient protection against 10 4 TCID50 of SARS‐CoV‐2 intratracheal challenge compared with the control group. These results highlight the BIV1‐CovIran vaccine as a potential candidate to induce a strong and potent immune response that may be a promising and feasible vaccine to protect against SARS‐CoV‐2 infection.

A Perspective on the Roles of Adjuvants in Developing Highly Potent COVID-19 Vaccines

“…Studies have shown that mice coadministered with a pharmacological inhibitor of elastase and alum-adsorbed SARS-CoV-2 S protein-based vaccines can develop high-affinity serum IgG and IgA antibodies [19], indicating that suppression of neutrophil elastase could improve the efficacy of alum-based injected vaccines. Immunization with the inactivated vaccine candidate BIV1-CovIran formulated with alum adjuvant elicited a high level of SARS-CoV-2-specific neutralizing antibodies in mice, rabbits and nonhuman primates (NHPs) [20]. Immunization with two doses of psoralen-inactivated whole-SARS-CoV-2 vaccine (SARS-CoV-2 PsIV) formulated with alum adjuvant generated dose-dependent neutralizing antibodies and Th2 cell responses in mice [21].…”

SARS-CoV-2 and Coronavirus Disease Mitigation: Treatment Options, Vaccinations and Variants

“…Various generic platforms were used to develop the vaccines, such as using viral protein, Adenovirus-vectored vaccines, using an inactivated virus, mRNA, or RNA-based vaccine [184]. [184], [186][187][188][189][190][191][192][193][194][195][196]. aration, more than 983.1 million vaccine doses have been given worldwide [185].…”

“…Status of COVID-19 Vaccines until 30 November 2021[184],[186][187][188][189][190][191][192][193][194][195][196].…”

“Effectiveness of COVID-19 Vaccines in preventing Infectiousness, Hospitalization and Mortality: A Historical Cohort Study Using Iranian Registration Data During Vaccination program”

“…The 4 vaccines studied against COVID-19 were [1] the BBIBP-CorV vaccine, which is a monovalent Vero cells vaccine composed of inactivated 19nCoV-CDC-Tan-HB02 (HB02) strain of SARS-CoV-2 virus antigens. [13] ; [2] the ChAdOx1-S/nCoV-19 vaccine, which is a modified rAd vector (ChAdOx1), containing the full-length codon-optimized coding sequence of the spike protein of SARS-CoV-2 (ChAdOx1-S/nCoV-19), with a tissue plasminogen activator leader sequence [14] ; [3] the rAd26-rAd5, which is a recombinant replication-deficient adenovirus (rAd)-based vaccine, containing rAd type 26 (rAd26) and rAd type 5 (rAd5) vectors that both of them carry the gene for SARS-CoV-2 full-length glycoprotein S (rAd26-S and rAd5-S) [2] ; and [4] the BIV1-CovIran (COVIran Barekat), which is an inactivated whole-virus SARS-CoV-2 vaccine [15] . The first two vaccines have been authorized for emergency use by WHO, while the other two vaccines have been listed for emergency use, regionally, so far.…”