TY - JOUR T1 - Genomic characterization and epidemiology of an emerging SARS-CoV-2 variant in Delhi, India. JF - Science Y1 - 2021 A1 - Dhar, Mahesh S A1 - Marwal, Robin A1 - Vs, Radhakrishnan A1 - Ponnusamy, Kalaiarasan A1 - Jolly, Bani A1 - Bhoyar, Rahul C A1 - Sardana, Viren A1 - Naushin, Salwa A1 - Rophina, Mercy A1 - Mellan, Thomas A A1 - Mishra, Swapnil A1 - Whittaker, Charles A1 - Fatihi, Saman A1 - Datta, Meena A1 - Singh, Priyanka A1 - Sharma, Uma A1 - Ujjainiya, Rajat A1 - Bhatheja, Nitin A1 - Divakar, Mohit Kumar A1 - Singh, Manoj K A1 - Imran, Mohamed A1 - Senthivel, Vigneshwar A1 - Maurya, Ranjeet A1 - Jha, Neha A1 - Mehta, Priyanka A1 - A, Vivekanand A1 - Sharma, Pooja A1 - Vr, Arvinden A1 - Chaudhary, Urmila A1 - Soni, Namita A1 - Thukral, Lipi A1 - Flaxman, Seth A1 - Bhatt, Samir A1 - Pandey, Rajesh A1 - Dash, Debasis A1 - Faruq, Mohammed A1 - Lall, Hemlata A1 - Gogia, Hema A1 - Madan, Preeti A1 - Kulkarni, Sanket A1 - Chauhan, Himanshu A1 - Sengupta, Shantanu A1 - Kabra, Sandhya A1 - Gupta, Ravindra K A1 - Singh, Sujeet K A1 - Agrawal, Anurag A1 - Rakshit, Partha A1 - Nandicoori, Vinay A1 - Tallapaka, Karthik Bharadwaj A1 - Sowpati, Divya Tej A1 - Thangaraj, K A1 - Bashyam, Murali Dharan A1 - Dalal, Ashwin A1 - Sivasubbu, Sridhar A1 - Scaria, Vinod A1 - Parida, Ajay A1 - Raghav, Sunil K A1 - Prasad, Punit A1 - Sarin, Apurva A1 - Mayor, Satyajit A1 - Ramakrishnan, Uma A1 - Palakodeti, Dasaradhi A1 - Seshasayee, Aswin Sai Narain A1 - Bhat, Manoj A1 - Shouche, Yogesh A1 - Pillai, Ajay A1 - Dikid, Tanzin A1 - Das, Saumitra A1 - Maitra, Arindam A1 - Chinnaswamy, Sreedhar A1 - Biswas, Nidhan Kumar A1 - Desai, Anita Sudhir A1 - Pattabiraman, Chitra A1 - Manjunatha, M V A1 - Mani, Reeta S A1 - Arunachal Udupi, Gautam A1 - Abraham, Priya A1 - Atul, Potdar Varsha A1 - Cherian, Sarah S AB -

Delhi, the national capital of India, has experienced multiple SARS-CoV-2 outbreaks in 2020 and reached population seropositivity of over 50% by 2021. During April 2021, the city became overwhelmed by COVID-19 cases and fatalities, as a new variant B.1.617.2 (Delta) replaced B.1.1.7 (Alpha). A Bayesian model explains the growth advantage of Delta through a combination of increased transmissibility and reduced sensitivity to immune responses generated against earlier variants (median estimates; ×1.5-fold, 20% reduction). Seropositivity of an employee and family cohort increased from 42% to 87.5% between March and July 2021, with 27% reinfections, as judged by increased antibody concentration after a previous decline. The likely high transmissibility and partial evasion of immunity by the Delta variant contributed to an overwhelming surge in Delhi.

ER - TY - JOUR T1 - SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion. JF - Nature Y1 - 2021 A1 - Mlcochova, Petra A1 - Kemp, Steven A A1 - Dhar, Mahesh Shanker A1 - Papa, Guido A1 - Meng, Bo A1 - Ferreira, Isabella A T M A1 - Datir, Rawlings A1 - Collier, Dami A A1 - Albecka, Anna A1 - Singh, Sujeet A1 - Pandey, Rajesh A1 - Brown, Jonathan A1 - Zhou, Jie A1 - Goonawardane, Niluka A1 - Mishra, Swapnil A1 - Whittaker, Charles A1 - Mellan, Thomas A1 - Marwal, Robin A1 - Datta, Meena A1 - Sengupta, Shantanu A1 - Ponnusamy, Kalaiarasan A1 - Radhakrishnan, Venkatraman Srinivasan A1 - Abdullahi, Adam A1 - Charles, Oscar A1 - Chattopadhyay, Partha A1 - Devi, Priti A1 - Caputo, Daniela A1 - Peacock, Tom A1 - Wattal, Chand A1 - Goel, Neeraj A1 - Satwik, Ambrish A1 - Vaishya, Raju A1 - Agarwal, Meenakshi A1 - Mavousian, Antranik A1 - Lee, Joo Hyeon A1 - Bassi, Jessica A1 - Silacci-Fegni, Chiara A1 - Saliba, Christian A1 - Pinto, Dora A1 - Irie, Takashi A1 - Yoshida, Isao A1 - Hamilton, William L A1 - Sato, Kei A1 - Bhatt, Samir A1 - Flaxman, Seth A1 - James, Leo C A1 - Corti, Davide A1 - Piccoli, Luca A1 - Barclay, Wendy S A1 - Rakshit, Partha A1 - Agrawal, Anurag A1 - Gupta, Ravindra K KW - Antibodies, Neutralizing KW - Cell Fusion KW - Cell Line KW - COVID-19 Vaccines KW - Female KW - Health Personnel KW - Humans KW - Immune Evasion KW - India KW - Kinetics KW - Male KW - SARS-CoV-2 KW - Spike Glycoprotein, Coronavirus KW - Vaccination KW - Virus Replication AB -

The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha). In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era.

VL - 599 IS - 7883 ER -