Repurposing NASVAC, a hepatitis B therapeutic vaccine, for pre- and postexposure prophylaxis of SARS-CoV-2 infection

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the subsequent coronavirus 2019 (COVID-19) have led to tens of millions of cases and millions of deaths around the world. Although more than a year has passed since the emergence of COVID-19, more waves of the pandemic, with new variants of the deadly virus, have been reported. It seems that the virus will continue to infect people for years or decades to come and thus lead to more illnesses and deaths. The experiences last year regarding limiting the transmission of the virus indicate that one or more traditional methods of containment may not be effective; further, even vaccination may not give immunity to society. On the other hand, eliminating the virus using drugs capable of eradicating SARS-CoV-2 from the infected host may not be an achievable goal. Based on these realities and after exploring the mechanism underlying the acquisition of the virus and pathogenesis of COVID-19, we assumed that immune therapy may be a practical option for the containment of SARS-CoV-2. In this study, we repurposed an immune modulator containing two antigens of hepatitis B virus, hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) (termed NASVAC, Center for Genetic Engineering and Biotechnology, CIGB, Havana, Cuba), to gain insight into its role against SARS-CoV-2. NASVAC induced cytokines of innate immunity following nasal administration and prevented all 20 volunteers from being diagnosed with SARS-CoV-2 during the two weeks of usage. Four volunteers were infected with SARS-CoV-2 two weeks after the end of NASVAC administration; three of them showed almost no symptoms and recovered without any intervention, and one with several comorbidities attended a hospital for four days and recovered completely. In conclusion, the administration of NASVAC to subjects at risk of SARS-CoV-2 infection was safe. The pattern of cytokine responses and absence of infection or mild COVID-19 infection of the subjects involved in the study are preliminary evidence indicating that this product may prevent or suppress SARS-CoV-2 infection at the initial stages of SARS-CoV-2 acquisition and/or replication and deserve further exploratory trials to confirm the capacity of NASVAC as pre/postexposure prophylaxis or pre-emptive therapy in the context of SARS-CoV-2 infection.

Photodynamic Therapy in Combination with the Hepatitis B Core Virus-like Particles (HBc VLPs) to Prime Anticancer Immunity for Colorectal Cancer Treatment

“…Our data shows that HBc VLPs stimulation can lead to obvious upregulation of the B cell surface markers CD40 and CD86 but the negligible level of CD40, which is due to the high basic expression level of CD40 on the B cell surface and is similar to the report from Lobaina et al [ 29 ]. Furthermore, the cytokine secretion (IL-12 and IFN-γ) of antigen-presenting cells (APCs) following stimulation is consistent with prior findings showing the production of inflammatory cytokines was increased in volunteers’ peripheral blood mononuclear cells and DCs one day after HBc VLPs treatment [ 25 , 40 ].…”