Vaccination effects on post-infection outcomes in the Omicron BA.2 outbreak in Shanghai

Figures & data

Figure 1. Flowchart of the included participants. Severe outcomes included the clinical outcomes of the severe, critical and fatal cases.

Table 1. Demographic characteristics (n, %).

	Asymptomatic (N = 14,934)	Mild-to-moderate (N = 32,776)	Severe (N = 533)
Age group
3–17 years	527 (3.5)	1197 (3.6)	1 (0.2)
18–59 years	11,836 (79.3)	27,651 (84.4)	75 (14.1)
60–79 years	2434 (16.3)	3682 (11.2)	261 (49.0)
80+ years	137 (0.9)	246 (0.8)	196 (36.8)
Sex
Male	9938 (66.5)	20,065 (61.2)	304 (57.0)
Female	4996 (33.5)	12,711 (38.8)	229 (43.0)
Vaccination courses
Unvaccinated	1823 (12.2)	3277 (10.0)	406 (76.2)
Partial
Inactivated (1 dose)	514 (3.4)	996 (3.0)	12 (2.4)
Protein subunit (1/2 doses)	6 (0.0)	30 (0.0)	-
Primary
Inactivated (2 doses)	5279 (35.3)	11,557 (35.3)	60 (11.1)
Ad-vectored (1 dose)	337 (2.3)	603 (1.8)	–
Protein subunit (3 doses)	41 (0.3)	248 (0.8)	2 (0.4)
Mixed	3 (0.0)	4 (0.0)	–
Booster
Inactivated (3 doses)	6776 (45.4)	15,760 (48.1)	51 (9.6)
Ad-vectored (2 doses)	151 (1.0)	286 (0.9)	2 (0.4)
Mixed	4 (0.0)	15 (0.0)	–
Days between last vaccination dose and positive PCR test result (median, IQR)
Partial	244 (172, 308)	232 (114, 300)	321 (283, 364)
Primary	284 (232, 314)	280 (223, 312)	292 (237, 333)
Booster	98 (77, 120)	97 (77, 122)	103 (79, 118)
Presence of comorbidity
0	12,406 (83.1)	26,650 (81.3)	70 (13.1)
1	1899 (12.7)	4602 (14.0)	122 (22.9)
2	489 (3.3)	1,135 (3.5)	133 (25.0)
≥3	140 (0.9)	389 (1.2)	208 (39.0)
Antiviral medications
Yes	86 (0.6)	411 (1.3)	94 (17.6)
No	14,848 (99.4)	32,365 (98.7)	439 (82.4)

Note: Mixed regimens included combination use of vaccines on difference platforms.

Table 2. Vaccine effects against disease progression by the vaccination status within the age categories (VEp, 95% CI).

		3–17 years	18–59 years	60–79 years	80+ years
Asymptomatic vs. mild-to-moderate (adjusting for age, sex and presence of comorbidity)
Overall	Partial	−40.9 (−141.8, 15.3)	−9.4 (−25.9, 4.8)	7.3 (−37.1, 37.0)	20.7 (−520.0, 87.4)
	Primary	−16.6 (−52.5, 11.0)	−26.3 (−37.9, −15.6)	−8.4 (−10.5, 15.7)	28.9 (−36.9, 62.6)
	Booster	NE	−44.1 (−57.0, −36.8)	−12.8 (−29.4, 1.7)	38.2 (−22.9, 68.7)
Inactivated	Partial	−39.5 (−139.4, 16.3)	−6.7 (−23.0, 7.2)	7.3 (−23.7, 37.0)	20.7 (−520.0, 87.4)
	Primary	−17.6 (−53.7, 10.3)	−26.2 (−37.9, −15.5)	−7.6 (−23.7, 6.4)	28.9 (−36.9, 62.6)
	Booster	NE	−44.9 (−58.0, −32.9)	−13.7 (−30.5, 0.9)	38.2 (−22.9, 68.7)
Ad-vectored	Primary	NE	−1.4 (−19.4, 13.7)	−31.3 (−159.7, 31.4)	NE
	Booster	NE	−23.0 (−54.0, 1.4)	63.7 (4.8, 87.5)	NE
Non-severe vs Severe (adjusting for age, sex, presence of comorbidity and antiviral medication)
Overall	Partial	NE	82.2 (−1.2, 99.1)	−14.8 (−137.3, 51.2)	−46.8 (−552.9, 71.9)
	Primary	NE	60.9 (24.7, 80.0)	68.0 (53.3, 78.6)	54.3 (1.3, 81.2)
	Booster	NE	76.0 (52.0, 88.3)	71.2 (57.5, 81.0)	71.1 (23.8, 91.5)
Inactivated	Partial	NE	82.3 (−1.0, 99.1)	−14.6 (−136.8, 51.3)	−46.8 (−552.9, 71.9)
	Primary	NE	63.3 (28.1, 81.7)	67.5 (52.7, 78.3)	54.3 (1.3, 81.2)
	Booster	NE	79.5 (58.0, 90.3)	71.1 (57.4, 80.9)	71.1 (23.8, 91.5)

Note: Non-severe outcomes included clinical severity as asymptomatic and mild-to-moderate illness. Severe outcomes included clinical severity as severe, critical, and fatal illness. NE (not estimated) indicated that the results cannot be estimated because of the small sample size.

Table 3. Time-varying vaccine effects against disease progression from nonsevere to severe outcomes within the age categories among the inactivated vaccine recipients (VEp, 95% CI).

	18–59 years	60–79 years	80+ years
Primary
<180 days	28.5 (−160.4, 89.0)	NE	42.3 (−508.2, 97.6)
≥180 days	69.5 (36.6, 86.2)	65.2 (48.2, 77.4)	63.8 (−0.3, 89.8)
Booster
<90 days	74.1 (33.6, 91.6)	71.4 (48.4, 85.7)	70.1 (−61.9, 98.4)
≥90 days	81.6 (57.7, 92.9)	66.6 (46.1, 80.3)	56.8 (−43.3, 90.6)

Covariates included age, sex, presence of comorbidity and antiviral medication. Non-severe outcomes included clinical severity as asymptomatic and mild-to-moderate illness. Severe outcomes included clinical severity as severe, critical, and fatal illness. NE (not estimated) indicated that the results cannot be estimated because of the small sample

Figure 2. Duration of infection by vaccination status. Severe outcomes included the clinical outcomes of the severe, critical and fatal cases. * represents p value < 0.05, ** represents p value < 0.01, *** represents p value < 0.001.

Data availability statement

The data analyzed are not publicly available as they contain personal information.