Variants of SARS Coronavirus-2 and Their Potential Impact on the Future of the COVID-19 Pandemic

The emergence of SARS-CoV-2 variants concern (VOCs), especially the sweeping spread delta variant, and differing public health management strategies, have rendered global eradication unlikely. currently available COVID-19 vaccines, including inactivated whole virus mRNA adenovirus-vectored are effective in protecting people from severe disease death COVID-19, but they may not confer good mucosal immunity to prevent establishment infection subsequent viral shedding transmission. Mucosal vaccines delivered via intranasal route provide a promising direction, which, if given as third dose after two-dose series intramuscular vaccination, likely promotes addition boosting systemic cell-mediated antibody response. However, induced by natural well, is wane followed re-infection case human coronaviruses OC43, 229E, NL63, HKU1. It challenge control worldwide with increasing number VOCs associated increased transmissibility changing antigenicity. Nevertheless, we seek end current pandemic situation through mass vaccination gradual relaxation non-pharmaceutical measures, which would limit incidence COVID-19. Repeated doses booster vaccine will be required, similar influenza virus, for elderly immunocompromised patients who most vulnerable infection.