Volume 28, Number 10—October 2022
Synopsis
Seasonality of Common Human Coronaviruses, United States, 2014–20211
, Amber Winn, Rebecca M. Dahl, Krista L. Kniss, Benjamin J. Silk, and Marie E. Killerby
Table 1
Onset, peak, and offset dates for 4 common HCoVs and percentage detection, by season, from weekly aggregated data submitted to the National Respiratory and Enteric Virus Surveillance System, United States, July 2014–November 2021*
| Season (MMWR wk) | Date (MMWR wk) |
HCoV, % |
||||||
|---|---|---|---|---|---|---|---|---|
| Onset | Peak | Offset | OC43 | NL63 | HKU1 | 229E | ||
| 2014–15 (31–30) | 2014 Nov 1 (44) | 2015 Feb 7 (5) | 2015 Jun 27 (25) | 6.3 | 23.5 | 58.8 | 11.4 | |
| 2015–16 (31–30) | 2015 Nov 7 (44) | 2016 Feb 13 (6) | 2016 May 14 (19) | 31.1 | 34.8 | 29.4 | 4.8 | |
| 2016–17 (31–30) | 2016 Nov 12 (45) | 2017 Feb 4 (5) | 2017 Apr 29 (17) | 1.8 | 10.0 | 56.8 | 31.4 | |
| 2017–18 (31–30) | 2017 Oct 21 (42) | 2018 Jan 6 (1) | 2018 Apr 21 (16) | 33.5 | 39.3 | 25.8 | 1.4 | |
| 2018–19 (31–30) | 2018 Nov 10 (45) | 2019 Feb 9 (6) | 2019 May 11 (19) | 5.8 | 25.3 | 49.9 | 19.0 | |
| 2019–20 (31–30) | 2019 Nov 2 (44) | 2020 Jan 18 (3) | 2020 Apr 18 (16) | 51.9 | 29.5 | 14.2 | 4.3 | |
| 2020–21 (31–44) | 2021 Jan 23 (03) | 2021 May 22 (20) | Not reached† | 1.6 | 31.6 | 55.8 | 10.9 | |
*Dates for season onset, peak, and offset for all seasons are based on the retrospective slope 10 method, which uses a centered 5-week moving average of weekly detections with normalization to peak to define seasonal inflections. Seasons were defined as starting on MMWR week 31 (beginning of August) of each year through MMWR week 30 (end of July) of the following year (https://ndc.services.cdc.gov/wp-content/uploads/MMWR_Week_ overview.pdf). For the last 2020–21 season, data were included from August 2021–November 2022 because of the delayed seasonal start. The percent of positive detections by each HCoV type by season (with the denominator being total positive detections of any HCoV type for that season) is included in the final 4 columns. HCoV, human coronavirus. †By November of 2021, normalized values had not reached the requirement for offset for the 2020–21 season.
1Preliminary results from this study were presented at the IDWeek Virtual Conference 2021,
September 29–October 3, 2021.