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• This study used laboratory data of 110 million tests for SARS-CoV-2 from India. • Molecular testing is preferred over rapid antigen tests in high caseload regions. • Positivity rates can be a reasonable marker for the need for additional testing. • Laboratory data can help us better understand the spread of the pandemic. India had the second-highest number of COVID-19 cases globally. We evaluated the progression of the pandemic across the lockdowns and phased reopenings at the district level during the first wave (in India). For the analysis in this study, we used more than 100 million COVID-19 test results along with other parameters available in the Indian Council of Medical Research database from March 2020 to October 2020. The districts were stratified as high, moderate, and low caseload districts and data analysis was done for each phase of lockdown. Of the 110.5 million tests included in the analysis, 54.79 million tests were performed using molecular methods, 53.58 million by rapid antigen tests, and 2.13 million using the indigenous TruNat platform. The proportion of positive cases among symptomatic individuals (22.6%) was significantly higher than asymptomatic individuals (8.6%). The tests conducted and proportions of positivity were significantly higher in high caseload districts; 58% of these tests were conducted using molecular methods as opposed to only one-third in low caseload districts. Laboratory parameters, along with other demographic information, can help us better understand the spread of the pandemic in a country. This information can be crucial to formulating and implementing public health policies in future waves of the pandemic. [ABSTRACT FROM AUTHOR]

• Whole-genome sequencing was performed for COVID-19-positive patients by ARTIC amplicon-based sequencing. • The spike region of 32 isolates showed one or multiple alterations in nucleotide bases compared with the Wuhan reference strain. • RBD of all Indian isolates showed binding affinity for angiotensin-converting enzyme 2 (ACE2) of humans, bats, hamsters and pangolins. • The mutated receptor-binding domain of one isolate showed stronger binding affinity for human ACE2. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected the whole world, including Odisha, a state in eastern India. Many people have migrated to the state from different countries as well as other states during this SARS-CoV-2 pandemic. The aim of this study was to analyse the receptor-binding domain (RBD) sequence of the spike protein from isolates collected from throat swab samples of COVID-19-positive patients and further to assess the RBD affinity for angiotensin-converting enzyme 2 (ACE2) of different species, including humans. Whole-genome sequencing for 35 clinical SARS-CoV-2 isolates from COVID-19-positive patients was performed by ARTIC amplicon-based sequencing. Sequence analysis and phylogenetic analysis were performed for the spike region and the RBD region of all isolates. The interaction between the RBD and ACE2 of five different species was also analysed. The spike region of 32 isolates showed one or multiple alterations in nucleotide bases in comparison with the Wuhan reference strain. One of the identified mutations, at position 1204 (Ref A, RMRC 22 C), in the RBD coding region of the spike protein showed stronger binding affinity for human ACE2. Furthermore, RBDs of all the Indian isolates showed binding affinity for ACE2 of different species. As mutant RBD showed stronger interaction with human ACE2, it could potentially result in higher infectivity. The binding affinity of the RBDs for ACE2 of all five species studied suggests that the virus can infect a wide variety of animals, which could also act as natural reservoir for SARS-CoV-2. [ABSTRACT FROM AUTHOR]