Emergence and spread of a B.1.1.28-derived lineage with Q675H and Q677H Spike mutations in Uruguay (preprint)

ABSTRACT

Uruguay was able to control the viral dissemination during the first nine months of the SARS-CoV-2 pandemic. Unfortunately, towards the end of 2020, the number of daily new cases exponentially increased. We previously identified a B.1.1.28 sublineage carrying mutations Q675H+Q677H in the viral Spike, with local transmission in Rocha, a department bordering Brazil. To understand whether these B.1.1.28+Q675H+Q677H sequences were part of an emergent SARS-CoV-2 lineage broadly disseminated in Uruguay, herein we analyzed the country-wide genetic diversity of viruses between November, 2020 and April, 2021. Our findings support that B.1.1.28+Q675H+Q677H probably arose around November 2020, in Montevideo, Uruguay's capital department. This clade spread to other Uruguayan departments, with evidence of further local transmission clusters. It also spread to the USA and Spain. The Q675H and Q677H mutations are in the proximity of the polybasic cleavage site at the S1/S2 boundary and also arose independently in many SARS-CoV-2 lineages circulating worldwide. Although in Uruguay the B.1.1.28+Q675H+Q677H lineage was dominated by the VOC P.1 since April 2021, the monitoring of the concurrent emergence of Q675H+Q677H in VOIs and/or VOCs should be of worldwide interest.