Table 2 Estimated virus transmissibility (RTX) and overall infection-fatality risk (IFR) during each wave/period

From: SARS-CoV-2 dynamics in New York City during March 2020–August 2023

Wave/variants

Calendar period

RTX

IFR (%)

1st wave (ancestral)

03/01/20–05/30/20

2.4 (1.33-3.68)

1.429 (0.979–1.903)

2nd wave (ancestral/Iota/Alpha)

10/04/20–05/29/21

2.86 (1.73-4.29)

0.397 (0.246–0.6)

Delta

07/04/21–12/04/21

3.75 (2.12-5.75)

0.241 (0.094–0.602)

Omicron BA.1

12/12/21–02/26/22

5.46 (3.73-7.35)

0.095 (0.047–0.166)

After BA.1

03/06/22–09/02/23

6.38 (4.15-9.37)

0.056 (0.022–0.136)

  1. Numbers show the median estimate (and 95% credible intervals). Note the calendar periods here were chosen based on the rough timing of pandemic waves (March–May 2020 for the 1st wave, October 2020–May 2021 for the 2nd wave, July–November 2021 for the Delta wave, and December 2021–August 2023 for Omicron subvariants; see Fig. 1), matching with the weekly intervals (hence the listed start dates) and excluding weeks with mixed circulation of variants (hence the missing weeks) in order to obtain more variant-specific estimates.
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