Table 1.
Comparison of clinical characteristics of adult COVID-19 patients with and without severe outcomes during BA.5 predominance (1 Aug 2022–31 Dec 2022) in Chiang Mai, Thailand.
| N = 63,009 | Without severe COVID-19 outcome | With severe COVID-19 outcome | p-value |
|---|---|---|---|
| Number (%) | 62884 (99.8) | 125 (0.2) | - |
| Age, years | |||
| Median (IQR) | 42 (30–60) | 72 (60–83) | <.01 |
| Age group, n (%) | |||
| 18–29 | 15090 (24.0) | 0 (0) | <.01 |
| 30–39 | 12996 (20.7) | 8 (6.4) | |
| 40–49 | 10089 (16.0) | 10 (8.0) | |
| 50–59 | 8829 (14.0) | 13 (10.4) | |
| 60–69 | 9651 (15.4) | 20 (16.0) | |
| ≥70 | 6229 (9.9) | 74 (59.2) | |
| Gender, n (%) | |||
| Male | 25411 (40.4) | 72 (57.6) | <.01 |
| Female | 37473 (59.6) | 53 (42.4) | |
| Vaccination Status, n (%) | |||
| Unvaccinated | 43423 (69.1) | 92 (73.6) | - |
| Vaccinated One dose | 153 (0.2) | 3 (2.4) | |
| Vaccinated two doses | 5915 (9.4) | 20 (16.0) | |
| Vaccinated three doses | 9190 (14.6) | 9 (7.2) | |
| Vaccinated four doses | 3699 (5.9) | 1 (0.8) | |
| Vaccinated five doses | 500 (0.8) | 0 (0) | |
| Vaccinated six doses | 4 (0.0) | 0 (0) | |
| Type of primary vaccine series, n (%) | n = 5915 | n = 20 | |
| Sinovac/BBIBP-CorV-ChAdOx1 nCoV-19 | 2031 (34.3) | 4 (20.0) | - |
| Sinovac-Sinovac or BBIBP-CorV-BBIBP-CorV | 769 (13.0) | 4 (20.0) | |
| ChAdOx1 nCoV-19-ChAdOx1 nCoV-19 | 616 (10.4) | 0 (0) | |
| BNT162b2-BNT162b2 | 740 (12.5) | 4 (20.0) | |
| ChAdOx1 nCoV-19-BNT162b2/mRNA-1273 | 1353 (22.9) | 8 (40.0) | |
| Sinovac/BBIBP-CorV-BNT162b2/mRNA-1273 | 35 (0.6) | 0 (0) | |
| mRNA-1273-mRNA-1273 | 371 (6.3) | 0 (0) | |
| Type of third vaccine dose, n (%) | n = 9190 | n = 9 | |
| BNT162b2 | 5223 (56.8) | 6 (66.7) | - |
| ChAdOx1 nCoV-19 | 1783 (19.4) | 2 (22.2) | |
| mRNA-1273 | 2182 (23.7) | 1 (11.1) | |
| Other | 2 (0.0) | 0 (0) | |
| Type of fourth vaccine dose, n (%) | n = 3698 | n = 1 | |
| BNT162b2 | 1395 (37.7) | 1 (100.0) | - |
| ChAdOx1 nCoV-19 | 87 (2.4) | 0 (0) | |
| mRNA-1273 | 2215 (59.9) | 0 (0) | |
| Other | 1 (0.0) | ||
| Type of fifth vaccine dose, n (%) | n = 500 | n = 0 | |
| BNT162b2 | 172 (34.4) | - | |
| mRNA-1273 | 328 (65.6) | ||
| Type of sixth vaccine dose, n (%) | n = 4 | n = 0 | |
| BNT162b2 | 1 (25.0) | - | |
| mRNA-1273 | 3 (75.0) | ||
| Previousa COVID-19 infection, n (%) | .264 | ||
| No previous COVID-19 infection | 58825 (93.5) | 120 (96.0) | |
| Previous COVID-19 infection | 4059 (6.5) | 5 (4.0) | |
| Time from previousa COVID-19 infection, n (%) | n = 4059 | n = 5 | |
| >90 days to 180 days | 708 (17.4) | 0 | .438 |
| >180 days to 270 days | 2179 (53.7) | 4 (80.0) | |
| >270 days | 1172 (28.9) | 1 (20.0) | |
| Immunity from vaccination and infection, n (%) | |||
| No vaccine or natural immunity | 41473 (65.9) | 91 (72.8) | <.01 |
| Natural immunity only | 2103 (3.3) | 4 (3.2) | |
| Primary vaccine series immunity only | 5173 (8.2) | 19 (15.2) | |
| Booster vaccine immunity only | 12179 (19.4) | 10 (8.0) | |
| Hybrid immunityb | 1956 (3.1) | 1 (0.8) |
IQR = Interquartile range.
aPrevious infection defined as a positive SARS-CoV-2 test before 90 days prior to index date.
bHybrid immunity defined as previous infection and completed at least primary COVID-19 vaccine series.