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 depressions. Europe and America were the hardest hit continents. India has also lost several 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 many of the developed nations. Several factors have been proposed including the 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 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 among states. We also found out that the cases reported by the Government were several fold lower than the real infection. This discrepancy is majorly driven by a 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, it is less likely to have a second wave in India.

Evolutionary event has not only transformed the genetic structure of human populations but also associated with social and cultural transformation. South Asian populations were formed as a result of such evolutionary events of migration and admixture of genetically and culturally distinct groups. Most of the genetic studies pointed to large-scale admixture event between Ancestral North Indian (ANI) and Ancestral South Indian (ASI) groups, also additional layers of recent admixture. In the present study we have analyzed 213 individuals inhabited in South West coast India with traditional warriors and feudal lord status and historically associated with recent migrations events and possible admixture with Indo-Scythians, Saka, Huns and Kushans, whose genetic links are still missing. Analysis of autosomal SNP markers suggests that these groups possibly derived their ancestry from some groups of North West India having additional Middle Eastern genetic component and also their separation history suggests very early separation from North West Indian and Gangetic plain Indo-Europeans during late bronze or Iron age, most probably following central India and Godavari basin to South West coast. Higher distribution of west Eurasian mitochondrial haplogroups also points to admixture through maternal lineage. Selection screen using genome wide genealogy approach revealed genetic signatures related to their long-term coastal food habits. Thus, our study suggests that the South West coastal groups with traditional warriors and feudal lords status are of a distinct lineage compared to Dravidian and Gangetic plain Indo-Europeans and are remnants of very early migrations from North West India following Godavari basin to Karnataka and Kerala.

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