RESUMO
After the spill to humans, in the timeline of SARS-CoV-2, several positively selected variants have emerged. A phylogeographic study on these variants can reveal their spatial and temporal distribution. In December 2020, the alpha variant of the severe acute respiratory syndrome coronavirus (SARS-CoV-2), which has been designated as a variant of concern (VOC) by WHO, was discovered in the southeastern United Kingdom (UK). Slowly, it expanded across India, with a considerable number of cases, particularly in North India. The study focuses on determining the prevalence and expansion of the alpha variants in various parts of India. The genetic diversity estimation helped us understand various evolutionary forces that have shaped the spatial distribution of this variant during the peak. Overall, our study paves the way to understand the evolution and expansion of a virus variant.
RESUMO
With the roll-out of worlds largest vaccine drive for Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) by Government of India on January 16 2021, India has targeted to vaccinate its entire population by the end of year 2021. Struggling with vaccine procurement and production earlier, India came up with these hurdles but the Indian population still did not seem to be mobilizing swiftly towards vaccination centers. With the initial hesitancy, as soon as the vaccination started to speedup, India was hit severely by the second wave. The severe second wave has slowed down the vaccination pace and also it was one of the major contributing factor of vaccine hesitancy. To understand the nature of vaccine hesitancy and factors underlying it, we conducted an extensive online and offline surveys in Varanasi and adjoining regions using structured questions. Majority of respondents though were students (0.633), respondents from other occupations such as government officials (0.10) were also included in the study. We observed several intriguing opinions on our eleven questions. It is interesting to note that the majority of the people (0.75) relied on fake news and did not take COVID-19 seriously. Most importantly, we noticed that a substantial proportion of respondents (relative frequency 0.151; mean age 24.8 years) reported that they are still not interested in vaccination. People who have neither been vaccinated nor have ever been infected may become the medium for spreading the virus and creating new variants. This could also lead to a resistant variant of the vaccine in the future. We expect that this extensive survey may help the government to upgrade their vaccination policies for COVID-19 in North India.
RESUMO
SARS-CoV2, the causative agent for COVID-19, an ongoing pandemic, engages the ACE2 receptor to enter the host cell through S protein priming by a serine protease, TMPRSS2. Variation in the TMPRSS2 gene may account for the difference in population disease susceptibility. The haplotype-based genetic sharing and structure of TMPRSS2 among global populations have not been studied so far. Therefore, in the present work, we used this approach with a focus on South Asia to study the haplotypes and their sharing among various populations worldwide. We have used next-generation sequencing data of 393 individuals and analysed the TMPRSS2 gene. Our analysis of genetic relatedness for this gene showed a closer affinity of South Asians with the West Eurasian populations therefore, host disease susceptibility and severity particularly in the context of TMPRSS2 will be more akin to West Eurasian instead of East Eurasian. This is in contrast to our prior study on ACE2 gene which shows South Asian haplotypes have a strong affinity towards West Eurasians. Thus ACE2 and TMPRSS2 have an antagonistic genetic relatedness among South Asians. We have also tested the SNPs frequencies of this gene among various Indian state populations with respect to the case fatality rate. Interestingly, we found a significant positive association between the rs2070788 SNP (G Allele) and the case fatality rate in India. It has been shown that the GG genotype of rs2070788 allele tends to have a higher expression of TMPRSS2 in the lung compared to the AG and AA genotypes, thus it might play a vital part in determining differential disease vulnerability. We trust that this information will be useful in underscoring the role of the TMPRSS2 variant in COVID-19 susceptibility and using it as a biomarker may help to predict populations at risk.
RESUMO
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.
RESUMO
The COVID-19 pandemic has resulted several waves of infection in many countries worldwide. The large variations in case fatality ratio among different geographical regions suggests that the human susceptibility against this virus varies substantially. Several studies from different parts of the world showed a significant association of ABO blood group and COVID-19 susceptibility. It was shown that individuals with blood group O are at the lower risk of coronavirus infection. To establish the association of ABO blood group in SARS-CoV-2 susceptibility, we for the first time analysed SARS-CoV-2 neutralising antibodies as well as blood groups among 509 random individuals from three major districts of Eastern Uttar Pradesh region of India.. Interestingly, we found neutralising antibodies in significantly higher percentage of people with blood group AB (0.36) followed by B (0.31), A (0.22) and lowest in people with blood group O (0.11). This indicates that people with blood group AB are at comparatively higher risk of infection than other blood groups. Further, in line to previous reports we too observed that people with blood group O have significantly decreased risk of SARS-CoV-2 infection. Thus, among the asymptomatic SARS-CoV-2 infected individuals with blood group AB has highest, whilst blood group O has lowest risk of infection.
RESUMO
Infection born by Coronavirus SARS-CoV-2 has swept the world within a time of a few months. It has created a devastating effect on humanity with social and economic depression. Europe and America were the hardest hit continents. India has also lost lives, making the country fourth most deadly worldwide. However, the infection and death rate per million and the case fatality ratio in India were substantially lower than in many developed nations. Several factors have been proposed including genetics. One of the important facts is that a large chunk of Indian population is asymptomatic to the SARS-CoV-2 infection. Thus, the real infection in India is much higher than the reported number of cases. Therefore, the majority of people are already immune in the country. To understand the dynamics of real infection as well as the level of immunity against SARS-CoV-2, we have performed antibody testing (serosurveillance) in the urban region of fourteen Indian districts encompassing six states. In our survey, the seroprevalence frequency varied between 0.01-0.48, suggesting high variability of viral transmission between states. We also found out that the cases reported by the government were several fold lower than the real incidence of infection. This discrepancy is mainly driven by the higher number of asymptomatic cases. Overall, we suggest that with the high level of immunity developed against SARS-CoV-2 in the majority of the districts, the case fatality rate of second wave in India will be minor than first wave.
