1. Comparative transmissibility of SARS-CoV-2 variants Delta and Alpha in New England, USA
- Author
-
Rebecca Earnest, Rockib Uddin, Nicholas Matluk, Nicholas Renzette, Sarah E. Turbett, Katherine J. Siddle, Christine Loreth, Gordon Adams, Christopher H. Tomkins-Tinch, Mary E. Petrone, Jessica E. Rothman, Mallery I. Breban, Robert Tobias Koch, Kendall Billig, Joseph R. Fauver, Chantal B.F. Vogels, Kaya Bilguvar, Bony De Kumar, Marie L. Landry, David R. Peaper, Kevin Kelly, Greg Omerza, Heather Grieser, Sim Meak, John Martha, Hannah B. Dewey, Susan Kales, Daniel Berenzy, Kristin Carpenter-Azevedo, Ewa King, Richard C. Huard, Vlad Novitsky, Mark Howison, Josephine Darpolor, Akarsh Manne, Rami Kantor, Sandra C. Smole, Catherine M. Brown, Timelia Fink, Andrew S. Lang, Glen R. Gallagher, Virginia E. Pitzer, Pardis C. Sabeti, Stacey Gabriel, Bronwyn L. MacInnis, Ryan Tewhey, Mark D. Adams, Daniel J. Park, Jacob E. Lemieux, Nathan D. Grubaugh, Ahmad Altajar, Alexandra DeJesus, Anderson Brito, Anne E. Watkins, Anthony Muyombwe, Brendan S. Blumenstiel, Caleb Neal, Chaney C. Kalinich, Chen Liu, Christopher Castaldi, Claire Pearson, Clare Bernard, Corey M. Nolet, David Ferguson, Erika Buzby, Eva Laszlo, Faye L. Reagan, Gina Vicente, Heather M. Rooke, Heidi Munger, Hillary Johnson, Irina R. Tikhonova, Isabel M. Ott, Jafar Razeq, James C. Meldrim, Jessica Brown, Jianhui Wang, Johanna Vostok, John P. Beauchamp, Jonna L. Grimsby, Joshua Hall, Katelyn S. Messer, Katie L. Larkin, Kyle Vernest, Lawrence C. Madoff, Lisa M. Green, Lori Webber, Luc Gagne, Maesha A. Ulcena, Marianne C. Ray, Marissa E. Fisher, Mary Barter, Matthew D. Lee, Matthew T. DeFelice, Michelle C. Cipicchio, Natasha L. Smith, Niall J. Lennon, Nicholas A. Fitzgerald, Nicholas Kerantzas, Pei Hui, Rachel Harrington, Randy Downing, Rashida Haye, Ryan Lynch, Scott E. Anderson, Scott Hennigan, Sean English, Seana Cofsky, Selina Clancy, Shrikant Mane, Stephanie Ash, Stephanie Baez, Steve Fleming, Steven Murphy, Sushma Chaluvadi, Tara Alpert, Trevor Rivard, Wade Schulz, Zoe M. Mandese, and Acibadem University Dspace
- Subjects
Delta ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,SARS-CoV-2 ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Alpha (ethology) ,COVID-19 ,Biology ,Transmissibility (vibration) ,General Biochemistry, Genetics and Molecular Biology ,Article ,New england ,New England ,Humans ,Viral rna ,Public Health ,Demography - Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant quickly rose to dominance in mid-2021, displacing other variants, including Alpha. Studies using data from the United Kingdom and India estimated that Delta was 40-80% more transmissible than Alpha, allowing Delta to become the globally dominant variant. However, it was unclear if the ostensible difference in relative transmissibility was due mostly to innate properties of Delta’s infectiousness or differences in the study populations. To investigate, we formed a partnership with SARS-CoV-2 genomic surveillance programs from all six New England US states. By comparing logistic growth rates, we found that Delta emerged 37-163% faster than Alpha in early 2021 (37% Massachusetts, 75% New Hampshire, 95% Maine, 98% Rhode Island, 151% Connecticut, and 163% Vermont). We next computed variant-specific effective reproductive numbers and estimated that Delta was 58-120% more transmissible than Alpha across New England (58% New Hampshire, 68% Massachusetts, 76% Connecticut, 85% Rhode Island, 98% Maine, and 120% Vermont). Finally, using RT-PCR data, we estimated that Delta infections generate on average ∼6 times more viral RNA copies per mL than Alpha infections. Overall, our evidence indicates that Delta’s enhanced transmissibility could be attributed to its innate ability to increase infectiousness, but its epidemiological dynamics may vary depending on the underlying immunity and behavior of distinct populations.
- Published
- 2021