A new study conducted by researchers at the University of Connecticut has revealed a correlation between the prevalence of particular clades of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the growth rate of the associated illness coronavirus disease 2019 (COVID-19).
Researchers found that models of early COVID-19 growth dynamics that included the different clades the virus has mutated into significantly improved growth rate predictions.
Including clades in the models was also more important than incorporating the SARS-CoV-2 variant D614G, which has been associated with increased viral load and infectivity.
More specifically, a higher prevalence of the clades 19A and 19B, which emerged during the Wuhan outbreak, correlated with lower growth rates. Higher prevalence of the clades 20A and 20C, which emerged from 19A and was prominent early on in the European outbreak, correlated with higher growth rates.
The researchers say that without intervention, COVID-19 has the potential to grow more quickly in regions dominated by the 20A and 20C clades, which includes most of South and North America.
Original study can be found on the medRxiv server and is currently under peer review: https://www.medrxiv.org/content/10.1101/2020.09.29.20202416v1
Association between COVID-19 outcomes and mask mandates, adherence, and attitudes
Using an event study design, authors estimate the treatment effect of the introduction of mask mandates (shown on the vertical red line) on Z-scored population-normalized COVID-19 daily new confirmed cases, daily new hospitalization admissions proportion, and deaths across all 50 states and D.C. over the time period between February 1 and September 27, 2020.
Source: Dhaval Adjodah, Karthik Dinakar, Matteo Chinazzi, Samuel P. Fraiberger, Alex Pentland, Samantha Bates, Kyle Staller, Alex Vespignani, Deepak L. Bhatt. Association between COVID-19 Outcomes and Mask Mandates, Adherence, and Attitudes.