Emerging SARS-CoV-2 variants: impact on vaccine efficacy and neutralizing antibodies.

The genetic variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been emerging and circulating in different parts of the world from the beginning of the coronavirus disease (COVID-19) pandemic. Variants are divided into three classes: variant of interest, variant of concern, and variant of high consequence depending on its impact on the transmission, disease severity, diagnostics, vaccines, and therapeutics. The variants of concern include the United Kingdom variant (B.1.1.7), South Africa variant (B.1.351), two related California variants (B.1.427 and B.1.429), and Brazil variant (P.1). These SARS-CoV-2 variants have a direct impact on the available COVID-19 vaccines and immunotherapeutics as they can alter the neutralizing activity of vaccine-elicited antibodies and monoclonal antibodies resulting in mild-to-substantial loss of efficacy. There is a need to establish surveillance systems that can monitor the emergence of novel SARS-CoV-2 variants worldwide.