ABSTRACT
BACKGROUND: Bangladesh introduced ChAdOx1 nCoV-19 since February, 2021 and in six months, only a small population (12.8%) received either one or two dose of vaccination like other low-income countries. The COVID-19 infections were continued to roll all over the places although the information on genomic variations of SARS-CoV-2 between both immunized and unimmunized group was unavailable. The objective of this study was to compare the proportion of immune escaping variants between those groups. METHODS: A total of 4718 nasopharygeal samples were collected from March 1 until April 15, 2021, of which, 834 (18%) were SARS-CoV-2 positive. The minimum sample size was calculated as 108 who were randomly selected for telephone interview and provided consent. The prevalence of SARS-CoV-2 variants and disease severity among both immunized and unimmunized groups was measured. A total of 63 spike protein sequences and 14 whole-genome sequences were performed from both groups and phylogenetic reconstruction and mutation analysis were compared. RESULTS: A total of 40 respondents (37%, N = 108) received single-dose and 2 (2%) received both doses of ChAdOx1 nCoV-19 vaccine, which significantly reduce dry cough, loss of appetite and difficulties in breathing compared to none. There was no significant difference in hospitalization, duration of hospitalization or reduction of other symptoms like running nose, muscle pain, shortness of breathing or generalized weakness between immunized and unimmunized groups. Spike protein sequence assumed 21 (87.5%) B.1.351, one B.1.526 and two 20B variants in immunized group compared to 27 (69%) B.1.351, 5 (13%) B.1.1.7, 4 (10%) 20B, 2 B.1.526 and one B.1.427 variant in unimmunized group. Whole genome sequence analysis of 14 cases identified seven B.1.351 Beta V2, three B.1.1.7 Alpha V1, one B.1.526 Eta and the rest three 20B variants. CONCLUSION: Our study observed that ChAdOx1 could not prevent the new infection or severe COVID-19 disease outcome with single dose while the infections were mostly caused by B.1.351 variants in Bangladesh.
Subject(s)
COVID-19 , SARS-CoV-2 , Bangladesh/epidemiology , COVID-19 Vaccines , ChAdOx1 nCoV-19 , Genomics , Humans , PhylogenyABSTRACT
Since the start of COVID-19 pandemic the Republic of Djibouti, in the horn of Africa, has experienced two epidemic waves of the virus between April and August 2020 and between February and May 2021. By May 2021, COVID-19 had affected 1.18% of the Djiboutian population and caused 152 deaths. Djibouti hosts several foreign military bases which makes it a potential hot-spot for the introduction of different SARS-CoV-2 strains. We genotyped fifty three viruses that have spread during the two epidemic waves. Next, using spike sequencing of twenty-eight strains and whole genome sequencing of thirteen strains, we found that Nexstrain clades 20A and 20B with a typically European D614G substitution in the spike and a frequent P2633L substitution in nsp16 were the dominant viruses during the first epidemic wave, while the clade 20H South African variants spread during the second wave characterized by an increase in the number of severe forms of COVID-19.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, is a readily transmissible and potentially deadly pathogen which is currently re-defining human susceptibility to pandemic viruses in the modern world. The recent emergence of several genetically distinct descendants known as variants of concern (VOCs) is further challenging public health disease management, due to increased rates of virus transmission and potential constraints on vaccine effectiveness. We report the isolation of SARS-CoV-2 VOCs imported into Australia belonging to the B.1.351 lineage, first described in the Republic of South Africa (RSA), and the B.1.1.7 lineage originally reported in the United Kingdom, and directly compare the replication kinetics of these two VOCs in Vero E6 cells. In this analysis, we also investigated a B.1.1.7 VOC (QLD1516/2021) carrying a 7-nucleotide deletion in the open reading frame 7a (ORF7a) gene, likely truncating and rendering the ORF7a protein of this virus defective. We demonstrate that the replication of the B.1.351 VOC (QLD1520/2020) in Vero E6 cells can be detected earlier than the B.1.1.7 VOCs (QLD1516/2021 and QLD1517/2021), before peaking at 48 h post infection (p.i.), with significantly higher levels of virus progeny. Whilst replication of the ORF7a defective isolate QLD1516/2021 was delayed longer than the other viruses, slightly more viral progeny was produced by the mutant compared to the unmutated isolate QLD1517/2021 at 72 h p.i. Collectively, these findings contribute to our understanding of SARS-CoV-2 replication and evolutionary dynamics, which have important implications in the development of future vaccination, antiviral therapies, and epidemiological control strategies for COVID-19.
Subject(s)
Open Reading Frames/genetics , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Viral Proteins/genetics , Virus Replication , Adult , Animals , Australia , COVID-19/prevention & control , COVID-19/transmission , COVID-19/virology , Chlorocebus aethiops , High-Throughput Nucleotide Sequencing , Humans , Kinetics , Middle Aged , Mutation , Nasopharynx/virology , Phylogeny , SARS-CoV-2/classification , South Africa , United Kingdom , Vero CellsABSTRACT
PURPOSE: We analyzed the SARS-CoV-2 genome using our integrated genome analysis system and present the concept of a comprehensive approach to monitoring and surveillance of emerging variants. MATERIAL/METHODS: A total of 69 SARS-CoV-2 positive samples (with Ct value â≤ â28) were tested. Samples included in this study were selected from 7 areas of eastern Poland. All samples were sequenced on an Illumina MiSeq platform using a 300-cycle MiSeq Reagent Kit v2. BWA was used for reads mapping on the reference SARS-CoV-2 sequence. SAMTools were used for post-processing of reads to genome assembly. Pango lineage and Nexstrain were used to identify variants and amino acid mutations. Statistical analysis was performed with R 4.0.2. RESULTS: This study shows the first confirmed case of SARS-CoV-2 in Poland with the lineage B.1.351 (known as 501Y.V2 South African variant), as well as another 18 cases with epidemiologically relevant lineage B.1.1.7, known as British variant. Supplementary analysis of SARS-CoV-2 sequences deposited in GISAID shows that the share of a new variant can change rapidly within one month. In addition, we show a complete, integrated concept of a networked system for analyzing the variability of the SARS-CoV-2 genome, which, used in the present study, generated data and a variant report within 6 days. CONCLUSION: The analyzed viral genomes showed considerable variability with simultaneous clear distinction of local clusters of genomes showing high similarity. Implementing real-time monitoring of new SARS-CoV-2 variants in Poland is urgently needed, and our developed system is available to be implemented on a large scale.
Subject(s)
COVID-19 , Epidemiological Monitoring , SARS-CoV-2 , Whole Genome Sequencing/methods , COVID-19/epidemiology , COVID-19/prevention & control , Computational Biology , Data Science , Genome, Viral , High-Throughput Nucleotide Sequencing/methods , Humans , Mutation , Poland/epidemiology , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purificationABSTRACT
We report here an imported case of SARS-CoV-2 variant of concern B.1.1.351 (also known as 20H/501Y.V2 or "South African variant" or VOC 202012/02) in a 66-years old symptomatic male who returned from Malawi to Italy.