(searched for: doi:10.1016/j.ajpath.2021.03.004)
Published: 5 July 2021
Virologica Sinica pp 1-14; doi:10.1007/s12250-021-00409-4
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Scientific Reports, Volume 11, pp 1-10; doi:10.1038/s41598-021-93145-4
COVID-19 global cases have climbed to more than 33 million, with over a million total deaths, as of September, 2020. Real-time massive SARS-CoV-2 whole genome sequencing is key to tracking chains of transmission and estimating the origin of disease outbreaks. Yet no methods have simultaneously achieved high precision, simple workflow, and low cost. We developed a high-precision, cost-efficient SARS-CoV-2 whole genome sequencing platform for COVID-19 genomic surveillance, CorvGenSurv (Coronavirus Genomic Surveillance). CorvGenSurv directly amplified viral RNA from COVID-19 patients’ Nasopharyngeal/Oropharyngeal (NP/OP) swab specimens and sequenced the SARS-CoV-2 whole genome in three segments by long-read, high-throughput sequencing. Sequencing of the whole genome in three segments significantly reduced sequencing data waste, thereby preventing dropouts in genome coverage. We validated the precision of our pipeline by both control genomic RNA sequencing and Sanger sequencing. We produced near full-length whole genome sequences from individuals who were COVID-19 test positive during April to June 2020 in Los Angeles County, California, USA. These sequences were highly diverse in the G clade with nine novel amino acid mutations including NSP12-M755I and ORF8-V117F. With its readily adaptable design, CorvGenSurv grants wide access to genomic surveillance, permitting immediate public health response to sudden threats.
Viruses, Volume 13; doi:10.3390/v13050930
Background: little is known about the forecasting of new variants of SARS-COV-2 in North America and the interaction of variants with vaccine-derived neutralizing antibodies. Methods: the affinity scores of the spike receptor-binding domain (S-RBD) of B.1.1.7, B. 1.351, B.1.617, and P.1 variants in interaction with the neutralizing antibody (CV30 isolated from a patient), and human angiotensin-converting enzyme 2 (hACE2) receptor were predicted using the template-based computational modeling. From the Nextstrain global database, we identified prevalent mutations of S-RBD of SARS-CoV-2 from December 2019 to April 2021. Pre- and post-vaccination time series forecasting models were developed based on the prediction of neutralizing antibody affinity scores for S-RBD of the variants. Results: the proportion of the B.1.1.7 variant in North America is growing rapidly, but the rate will reduce due to high affinity (~90%) to the neutralizing antibody once herd immunity is reached. Currently, the rates of isolation of B. 1.351, B.1.617, and P.1 variants are slowly increasing in North America. Herd immunity is able to relatively control these variants due to their low affinity (~70%) to the neutralizing antibody. The S-RBD of B.1.617 has a 110% increased affinity score to the human angiotensin-converting enzyme 2 (hACE2) in comparison to the wild-type structure, making it highly infectious. Conclusion: The newly emerged B.1.351, B.1.617, and P.1 variants escape from vaccine-induced neutralizing immunity and continue circulating in North America in post- herd immunity era. Our study strongly suggests that a third dose of vaccine is urgently needed to cover novel variants with affinity scores (equal or less than 70%) to eliminate developing viral mutations and reduce transmission rates.
Published: 20 April 2021
Severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) variants poses major threats in increasing infectivity, transmission, mortality of Coronavirus Disease 2019 (Covid-19). Additionally, SARS CoV-2 variants resist antibody neutralizations or may abolish vaccine efficacies. Researches to develop economical and fast methods will support the developing or poor countries to challenge the Covid-19 pandemic via tracking common mutations that may help to deploy the vaccination programs and control the virus. Current study has developed a novel low-cost rapid technique, exploiting real time PCR probes and conventional PCR specific primers, to identify N501Y mutation, which was independently emerged in the UK, South African and Brazilian variants. Currently, these variants tend to spread to all over the world and seem to be more infectious, transmissible and fatal. This study helps tracking the N501Y mutation for understanding its clinical and epidemiological characteristics, in those countries where sequencing facilities are lacking or expensive. Further study should focus on other common mutations in the variants of concerns of SARS CoV-2.