Razi Cov Pars

The COVID-19 pandemic has underscored the pressing need for safe and effective booster vaccines, particularly in considering the emergence of new SARS-CoV-2 variants and addressing vaccine distribution inequalities. Dissolving microneedle array patches (MAP) offer a promising delivery method, enhancing immunogenicity and improving accessibility through the skin's immune potential. In this study, we evaluated a microneedle array patch-based S1 subunit protein COVID-19 vaccine candidate, which comprised a bivalent formulation targeting the Wuhan and Beta variant alongside a monovalent Delta variant spike proteins in a murine model. Notably, the second boost of homologous bivalent MAP-S1(WU + Beta) induced a 15.7-fold increase in IgG endpoint titer, while the third boost of heterologous MAP-S1RS09Delta yielded a more modest 1.6-fold increase. Importantly, this study demonstrated that the administration of four doses of the MAP vaccine induced robust and long-lasting immune responses, persisting for at least 80 weeks. These immune responses encompassed various IgG isotypes and remained statistically significant for one year. Furthermore, neutralizing antibodies against multiple SARS-CoV-2 variants were generated, with comparable responses observed against the Omicron variant. Overall, these findings emphasize the potential of MAP-based vaccines as a promising strategy to combat the evolving landscape of COVID-19 and to deliver a safe and effective booster vaccine worldwide.

COVID-19 vaccines have played an important role in reducing the impact of the current pandemic. Previously, we developed NARUVAX-C19 vaccine based on a recombinant Wuhan spike protein extracellular domain expressed in insect cells and formulated with a squalene emulsion adjuvant (Sepivac SWE™). The current study assessed the immunogenicity, efficacy, and safety of NARUVAX-C19 vaccine in rhesus macaques and hamsters. Macaques immunized intramuscularly with two doses of NARUVAX-C19 vaccine showed no adverse effects and demonstrated cellular immunity as assessed by T cell IFN-γ responses against spike protein, in addition to inducing a humoral response. Serum from immunized animals neutralized the homologous wild-type SARS-CoV-2 virus as well as the Alpha and Delta variants. In hamsters, immunization with NARUVAX-C19 vaccine protected against a heterologous challenge with the Delta virus, as reflected by reduced lung and nasal viral loads and lung pathology in immunized animals. Nevertheless, some NARUVAX-C19 vaccinated animals were still shown to transmit infection to naïve sentinel animals. Overall, NARUVAX-C19 vaccine induced broadly cross-neutralizing antibody and T cell IFN-γ responses in rhesus macaques and provided heterologous protection of hamsters against infection by the Delta virus variant. This data supports the utility of squalene emulsion-based adjuvanted recombinant vaccine in protection against SARS-CoV-2 and supports their continued clinical development.