Table 2.

Summary of studies on the reproduction number of the alpha variant

Study	Location	Study date	Method	Estimated R0	Other findings
Curran et al.	UK	August, 2020 to December, 2020	Rapid scoping review approach		Transmissibility: 52% (95% CI 46, 58) higher than the other variants Growth rate: 71% (95% CI 65–75%) higher than the other variants
Grabowski et al.	UK	October, 2020 to December, 2020	Based on GISAID data available and Genome Sequence Analysis		Replicative advantage of B.1.1.7 over 20A.EU1: 1.83–2.18 (95% CI 1.71–2.40) Replicative advantage of B.1.1.7 over other strains: 2.03–2.47 (95% CI1.89–2.77)
Hunter et al.	UK	October, 2020 to December, 2020	R for preceding days was obtained by summing all reports of new COVID infections for each day and the previous six days. This was then compared with the sum of new cases over the previous 7-day period		Rt value for B.1.1.7: 1.3, 1.3 and 1.1 Rt value for other strains: 0.92, 0.91 and 0.97 In England, London and South East regions
Davies et al.	UK	March, 2020 to December, 2020	Using a time-varying multinomial spline model		Increased growth rate of + 0.104 day–1 [95% CI 0.100 to 0.108] relative to the previous variant 77% (95% CI 73 to 81%) higher R value
Washington et al.	US	December 2020 to January 2021	SARS-CoV-2 sequencing and Phylogenetic analyses		35–46% increased transmissibility
Sheikhi et al.	Iran	April, 2021 to April, 2021	EGR, ML, SB, and SIR models	R0: 2.26–11.38 using statistical models 12.13 by time-dependent SIR model (in the time interval with exponential growth)