ABSTRACT
Studies worldwide have shown that the available vaccines are highly effective against SARS-CoV-2. However, there are growing laboratory reports that the newer variants of concerns (VOCs e.g. Alpha, Beta, Delta etc) may evade vaccine induced defense. In addition to that, there are few ground reports on health workers having breakthrough infections. In order to understand VOC driven breakthrough infection we investigated 14 individuals who tested positive for SARS-CoV-2 after being administered a single or double dose of Covishield (ChAdOx1, Serum Institute of India) from the city of Varanasi, which is located in the Indian state of Uttar Pradesh. Genomic analysis revealed that 78.6% (11/14) of the patients were infected with the B.1.617.2 (Delta) variant. Notably, the frequency (37%) of this variant in the region was significantly lower (p<0.01), suggesting that the vaccinated people were asymmetrically infected with the Delta variant. Most of the patients tested displayed mild symptoms, indicating that even a single dose of the vaccine can help in reducing the severity of the disease. However, more comprehensive epidemiological studies are required to understand the effectiveness of vaccines against the newer VOCs.
Subject(s)
Breakthrough PainABSTRACT
Emerging variants of SARS-CoV-2 with increased transmissibility or immune escape have been causing large outbreaks of COVID-19 infections across the world. As most of the vaccines currently in use have been derived from viral strains circulating in the early part of the pandemic, it becomes imperative to constantly assess the efficacy of these vaccines against emerging variants. In this hospital-based cohort study, we analysed clinical profiles and outcomes of 1161 COVID-19 hospitalized patients (vaccinated with COVISHIELD (ChAdOx1) or COVAXIN (BBV-152), n = 495 and unvaccinated n = 666) in Hyderabad, India between April 24th and May 31st 2021. Viral genome sequencing revealed that >90% of patients in both groups were harbouring the Delta variant (Pango lineage B.1.617.2) of SARS-CoV-2. Vaccinated individuals showed higher neutralizing antibodies (545+-1256 AU/ml Vs 51.1+-296 AU/ml; p<0.001) and significantly decreased Ferritin (392.26+-448.4 ng/mL Vs 544.82+-641.41 ng/mL; p<0.001) and LDH (559.45+-324.05 U/L Vs 644.99+- 294.03 U/L; p<0.001), when compared to the unvaccinated group. Severity of the disease (3.2% Vs 7.2%; p=0.0039) and requirement of ventilatory support (2.8% Vs 5.9%; p=0.0154) were significantly low in the vaccinated group despite the fact that these individuals had significantly higher age and risk factors. The rate of mortality was about 50% lower (2/132=1.51%) in the completely vaccinated breakthrough infections although mortality in individuals who had received a single dose was similar to the unvaccinated group (9/269=3.35% vs 23/666= 3.45%). Our results demonstrate that both COVISHIELD and COVAXIN are effective in preventing disease severity and mortality against the Delta variant in completely vaccinated hospitalized patients.
Subject(s)
COVID-19ABSTRACT
Background:With the increasing COVID-19 infection worldwide, economization of the existing RT-PCR based detection assay becomes the need of the hour. Methods: An assessment of optimal PCR conditions for simultaneous amplification for E, S and RdRp gene of SARS-CoV-2 has been made using both fast traditional and multiplex real time PCR using same primer sets. All variables of practical value were studied by amplifying known target-sequences from ten-fold dilutions of archived positive samples of COVID-19. Results: The designed primers for amplification of E, S and RdRp gene of SARS-Cov-2 in single tube Multiplex PCR amplifications have shown efficient amplification of the target region in 37 minutes using thermal cyclers and 169 minutes with HRM based Real time detection using SYBR green master mix, over a wide range of template concentration, and the results were in good concordance with the commercially available detection kits. Conclusion: This fast HRM based Real time multiplex PCR with SYBR green approach offers rapid and sensitive detection of SARS-CoV-2 in a cost effective manner apart from the added advantage of primer pair’s compatibility for use in Traditional multiplex PCR, which offers extended applicability of the assay protocol in resource limited setting.
Subject(s)
COVID-19ABSTRACT
Since its zoonotic transmission in the human host, the SARS-CoV-2 virus has infected millions and has diversified extensively. A hallmark feature of viral system survival is their continuous evolution and adaptation within the host. RNA editing via APOBEC and ADAR family of enzymes has been recently implicated as the major driver of intra-host variability of the SARS-CoV-2 genomes. Analysis of the intra-host single-nucleotide variations (iSNVs) in SARS-CoV-2 genomes at spatio-temporal scales can provide insights on the consequence of RNA editing on the establishment, spread and functional outcomes of the virus. In this study, using 1,347 transcriptomes of COVID-19 infected patients across various populations, we find variable prevalence of iSNVs with distinctly higher levels in Indian population. Our results also suggest that iSNVs can likely establish variants in a population. These iSNVs may also contribute to key structural and functional changes in the Spike protein that confer antibody resistance.
Subject(s)
COVID-19 , InfectionsABSTRACT
Prevention of SARS-CoV-2 infection at the point of nasal entry is a novel strategy that has the potential to help contain the ongoing pandemic. Using our proprietary technologies, we have engineered a human antibody that recognizes SARS-CoV-2 S1 spike protein with an enhanced affinity for mucin to improve the antibodys retention in respiratory mucosa. The modified antibody, when administered into mouse nostrils, was shown to block infection in mice that were exposed to high titer SARS-CoV-2 pseudovirus 10 hours after the initial antibody treatment. Our data show that the protection against SARS-CoV-2 infection is effective in both nasal and lung areas 7 days after viral exposure. The modified antibody is stable in a nasal spray formulation and maintains its SARS-CoV-2 neutralizing activity. Nasal spray of the modified antibody can be developed as an affordable and effective prophylactic product to protect people from infection by exposure to SARS-CoV-2 virus in the air. One-sentence summaryA Fc-modified human antibody prevents SARS-CoV-2 viral infection via nasal administration
Subject(s)
COVID-19 , Heart BlockABSTRACT
COVID-19 manifests regarding extreme acute respiratory conditions caused by a novel beta coronavirus (SARS-CoV-2) which is reported to be the seventh coronavirus to infect humans. Like other SARS-CoVs it has a large positive-stranded RNA genome. But specific furin site in the spike protein, mutation prone and phylogenetically mess Orf1ab separates SARS-CoV-2 from other RNA viruses. Since, the outbreak (February - March 2020) which originated in China, researchers, scientists, and medical professionals are inspecting all possible facts from every possible aspect including its replication, detection, and prevention strategies. This led to the prompt identification of its basic biology, genome characterization, structural based functional information of proteins, and strategies to prevent its spread. Due to the rapid mutation rate, the functional characterization of a few proteins is still lagging. This review summarizes the recent updates on the basic molecular biology of SARS-CoV-2 and prevention strategies undertaken worldwide to tackle COVID-19. This recent information can be implemented for the development and designing of therapeutics against SARS-CoV-2.
Subject(s)
COVID-19 , Severe Acute Respiratory SyndromeABSTRACT
From an isolated epidemic, COVID-19 has now emerged as a global pandemic. The availability of genomes in the public domain following the epidemic provides a unique opportunity to understand the evolution and spread of the SARS-CoV-2 virus across the globe. The availability of whole genomes from multiple states in India prompted us to analyse the phylogenetic clusters of genomes in India. We performed whole-genome sequencing for 64 genomes making a total of 361 genomes from India, followed by phylogenetic clustering, substitution analysis, and dating of the different phylogenetic clusters of viral genomes. We describe a distinct phylogenetic cluster (Clade I / A3i) of SARS-CoV-2 genomes from India, which encompasses 41% of all genomes sequenced and deposited in the public domain from multiple states in India. Globally 3.5% of genomes, which till date could not be mapped to any distinct known cluster fall in this newly defined clade. The cluster is characterized by a core set of shared genetic variants - C6312A (T2016K), C13730T (A88V/A97V), C23929T, and C28311T (P13L). Further, the cluster is also characterized by a nucleotide substitution rate of 1.4 x 10-3 variants per site per year, lower than the prevalent A2a cluster, and predominantly driven by variants in the E and N genes and relative sparing of the S gene. Epidemiological assessments suggest that the common ancestor emerged in the month of February 2020 and possibly resulted in an outbreak followed by countrywide spread, as evidenced by the low divergence of the genomes from across the country. To the best of our knowledge, this is the first comprehensive study characterizing the distinct and predominant cluster of SARS-CoV-2 in India.