PreprintCited by 298SARS-CoV-2 and COVID-19 ResearchCOVID-19 epidemiological studiesCOVID-19 Clinical Research Studies

Genomic characterization and Epidemiology of an emerging SARS-CoV-2 variant in Delhi, India

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Dhar, Mahesh S, Marwal, Robin, Radhakrishnan, VS, Ponnusamy, Kalaiarasan, Jolly, Bani, Bhoyar, Rahul C., Sardana, Viren, Naushin, Salwa +40 more·2021·Science

Preprint — published as 10.1126/science.abj9932

Abstract

Delhi, the national capital of India, has experienced multiple SARS-CoV-2 outbreaks in 2020 and reached a 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 partial reduction of immunity elicited by prior infection (median estimates; ×1.5-fold, 20% reduction). Seropositivity of an employee and family cohort increased from 42% to 86% between March and July 2021, with 27% reinfections, as judged by increased antibody concentration after previous decline. The likely high transmissibility and partial evasion of immunity by the Delta variant contributed to an overwhelming surge in Delhi. One-Sentence Summary: Delhi experienced an overwhelming surge of COVID-19 cases and fatalities peaking in May 2021 as the highly transmissible and immune evasive Delta variant replaced the Alpha variant.

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Authors
Dhar, M. S., Marwal, R., Radhakrishnan, V., Ponnusamy, K., Jolly, B., Bhoyar, R. C., Sardana, V., Naushin, S., Rophina, M., Mellan, T. A., Mishra, S., Whittaker, C., Fatihi, S., Datta, M., Singh, P., Sharma, U., Ujjainiya, R., Batheja, N., Divakar, M. K., Singh, M. K., Imran, M., Senthivel, V., Maurya, R., Jha, N., Mehta, P., Vivekanand, A., Sharma, P., Arvinden, V., Chaudhary, U., Soni, N., Thukral, L., Flaxman, S., Bhatt, S., Pandey, R., Dash, D., Faruq, M., Lall, H., Gogia, H., Madan, P., Kulkarni, S., Chauhan, H., Sengupta, S., Kabra, S., The Indian SARS-CoV-2 Genomics Consortium (INSACOG), Gupta, R. K., Singh, S. K., Agrawal, A., & Rakshit, P.
Affiliations
  • National Center for Disease Control (IN)
  • Institute of Genomics and Integrative Biology (IN)
  • Imperial College London (GB)
  • University of Copenhagen (DK)
  • University of Cambridge (GB)
Corresponding author
  • Dhar, Mahesh S
  • Marwal, Robin
  • Ponnusamy, Kalaiarasan
  • Jolly, Bani
  • Bhoyar, Rahul C.
  • Agrawal, Anurag
  • Rakshit, Partha
Venue
Science
Publisher
openRxiv
Published
2021-06-03
Volume
374
Issue
6570
Pages
995-999
ISSN
0036-8075 (ISSN-L)
OpenAlex
W3205588626
Cited by
296
References
43
Citations by year
2026: 7 · 2025: 19 · 2024: 38 · 2023: 65 · 2022: 115 · 2021: 51 · 2020: 1
FWCI
21.30
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Science (publishedVersion, cc-by)
  • medRxiv (acceptedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Research at the University of Copenhagen (University of Copenhagen) (publishedVersion, cc-by)
  • Greater South Information System
Funders
  • Wellcome Trust (108082/A/15/Z, 108082)
  • Novo Nordisk Fonden (NNF20OC0059309)
  • Medical Research Council (MR/R015600/1, MC_PC_19012)
  • Engineering and Physical Sciences Research Council (EP/V002910/1, EP/V002910/2)
Topics
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
  • Physical Sciences › Mathematics › Modeling and Simulation › COVID-19 epidemiological studies
  • Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
Keywords
SARS-CoV-2, Delta variant, B.1.1.7 Alpha variant, COVID-19 outbreak, Delhi, genomic profiling, epidemiology, transmissibility, immune evasion, reinfection, seroprevalence, antibody response, Bayesian model
MeSH terms
Reinfection, COVID-19, Adolescent, Adult, Child, Humans, India, Phylogeny, Seroepidemiologic Studies, Genome, Viral, Molecular Epidemiology, Young Adult, Immune Evasion

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