Characterization of the emerging B.1.621 variant of interest of SARS-CoV-2

Abstract

The SARS-CoV-2 genetic diversification has a potential impact in the virus escape from natural infection- or vaccine-elicited neutralizing antibodies and higher transmissibility. Here we report the emergence of novel B.1.621 variant of interest with the insertion 145N in the N-terminal domain and amino acid change N501Y, E484K, and P681H in the Receptor Binding Domain of the Spike protein. Further studies in vitro biological assays and epidemiologic analysis will allow evaluating the public health impact of B.1.621 variant.

The impact of vaccination strategies for COVID-19 in the context of emerging variants and increasing social mixing in Bogotá, Colombia: a mathematical modelling study

“…To calibrate the parameters related to transmission and immunity escape for the different variants, we used the ranges reported in the literature (Table S2). The date of introduction of variants was estimated using reported cases from international travelers and the prevalence of variants in their countries of origin [29], as well as the presence of the emerging B.1.621 variant in the country of origin [6]. Hence, the total number of imported infections from variant ‘ v ’ can be estimated as where N(t) is the total imports detected in the city for time ‘t’ ;□ □ (□,□) is the dominance of variant ‘v’ in country ‘c’ at time ‘ t ’ as reported at [22] as of June 30th, 2021; □ □ is the overall proportion of importations detected in the city from country ‘ c ’; and □ □ is a scaling factor estimated using daily deaths and dominance data from sequenced samples.…”

“…We estimated that the B.1.621 variant is likely to be 1.2 (1.2 -1.98) times more transmissible and able to evade immunity from previous infections at 37% (19% -48%), compared to the original lineages. We estimated the potential early introduction of the alpha variant in Bogotá to be around November 2020, followed by the introduction of gamma early in January, 2021 (Fig S2 ), whereas the appearance of B.1.621 may have occurred later in the month [6]. Based on this framework, our baseline scenario assumed that importations from the delta variant may have started in Bogotá since May, 2021 (Fig S2 ), but in such a case, delta would not become dominant before August (Fig S3).…”

“…To calibrate the parameters related to transmission and immunity escape for the different variants, we used the ranges reported in the literature (Table 1). The date of introduction of variants was estimated using reported cases from international travelers and the prevalence of variants in their countries of origin [28], as well as the presence of the emerging B.1.621 variant in the country of origin [6]. Hence, the total number of imported infections from variant 'v' can be estimated as…”

“…The alpha variant (B.1.1.7) was first reported on April 16, 2021, and the gamma variant (P.1) on January 29, 2021. In addition, several regions in Colombia have reported since the beginning of January the B.1.621 variant, which then became dominant during the third wave of COVID-19 [6]. The delta variant (B.1.617.2) was reported on July 24, 2021.…”

Shared Mutations in Emerging SARS-CoV-2 Circulating Variants May Lead to Reverse Transcription-PCR (RT-PCR)-Based Misidentification of B.1.351 and P.1 Variants of Concern

“…B.1.621 is a VOI, as defined by the World Health Organization ( 4 ). It harbors several mutations affecting the spike protein, including E484K and N501Y ( 5 ). There are limited data on the global distribution of this variant, which has become predominant in some regions of Colombia, with up to 7% of sequenced cases.…”