Characteristics and factors of repeated influenza vaccination among elderly individuals in Shanghai, China from 2020 to 2022

Figures & data

Table 1. Distribution of influenza vaccination coverage among registered elderly individuals of different age groups in Shanghai, China, from 2020 to 2022.

Year	Total population	Registered population	Influenza vaccination among registered older individuals
			60–64			65–79			80+			Subtotal
			Population	Vaccination (%)	Coverage	Population	Vaccination (%)	Coverage	Population	Vaccination (%)	Coverage	Population	Vaccination	Coverage
2020	109.46	92.54	9.57	0.47 (26.04)	4.91	17.18	1.11 (61.65)	6.48	6.02	0.22 (12.32)	3.70	32.77	1.81	5.51
2021	111.47	92.99	9.11	0.27 (22.50)	2.99	18.29	0.77 (63.68)	4.21	6.09	0.17 (13.82)	2.75	33.48	1.21	3.61
2022	111.48	94.01	8.36	0.20 (18.25)	2.37	19.46	0.74 (67.67)	3.78	6.14	0.15 (14.09)	2.50	33.96	1.09	3.20

Units of population in ten thousand people; the numbers in parentheses represent the proportions.

Figure 1. Displays of the influenza vaccination, repeated vaccination, and AEFI among older individuals in Shanghai, China from 2020 to 2022. AEFI: adverse events following immunization.

(a) The number of older individuals who received influenza vaccines; (b) The rate of repeated influenza vaccination; (c) The reported incidence of adverse events following immunization.

Table 2. Distribution of repeated influenza vaccination among elderly individuals in Shanghai, China, from 2020 to 2022.

Variable Group	2020 (n = 2.08)		2021 (n = 1.42)		2022 (n = 1.29)		Total (N = 4.78)
	Non-repeated vaccination	Repeated vaccination	Non-repeated vaccination	Repeated vaccination	Non-repeated vaccination	Repeated vaccination	Non-repeated vaccination	Repeated vaccination
Type of vaccination clinic
Special clinics	0.26 (90.22)	0.03 (9.78)	0.14 (62.14)	0.08 (37.86)	0.10 (52.70)	0.09 (47.30)	0.49 (71.44)	0.20 (28.56)
Community clinics	1.23 (68.64)	0.56 (31.36)	0.38 (31.82)	0.82 (68.18)	0.36 (32.77)	0.74 (67.23)	1.97 (48.19)	2.12 (51.81)
Gender
Female	0.85 (72.16)	0.33 (27.84)	0.29 (36.86)	0.50 (63.14)	0.26 (36.19)	0.46 (63.81)	1.41 (52.08)	1.30 (47.92)
Male	0.64 (70.99)	0.26 (29.01)	0.22 (35.97)	0.40 (64.03)	0.19 (34.86)	0.36 (65.14)	1.05 (50.87)	1.02 (49.13)
Household registration
Non-shanghai	0.24 (86.20)	0.04 (13.80)	0.12 (59.44)	0.08 (40.56)	0.10 (52.70)	0.09 (47.30)	0.46 (68.34)	0.21 (31.66)
Shanghai	1.25 (69.45)	0.55 (30.55)	0.39 (32.55)	0.82 (67.45)	0.35 (32.56)	0.73 (67.44)	2.00 (48.80)	2.10 (51.20)
Age group
60–69	0.92 (77.23)	0.27 (22.77)	0.33 (40.02)	0.49 (59.98)	0.28 (37.70)	0.46 (62.30)	1.53 (55.59)	1.22 (44.41)
70–79	0.44 (67.64)	0.21 (32.36)	0.15 (33.47)	0.30 (66.53)	0.14 (33.66)	0.27 (66.34)	0.72 (48.25)	0.78 (51.75)
≥80	0.13 (54.39)	0.11 (45.61)	0.04 (26.81)	0.12 (73.19)	0.04 (29.99)	0.09 (70.01)	0.21 (39.94)	0.32 (60.06)
Total	1.49 (71.65)	0.59 (28.35)	0.52 (36.47)	0.90 (63.53)	0.46 (35.62)	0.83 (64.38)	2.46 (51.55)	2.32 (48.45)

Units of population in ten thousand people; the numbers in parentheses represent the proportions.

Table 3. Ordered multinomial logistic regression analysis on the factors influencing the number of repeated influenza vaccination among elderly individuals in Shanghai.

Variable Group	β	Waldχ^2	OR (95%CI)	P
Type of vaccination clinic
Special clinics			Reference
Community clinics	0.744	0.674	2.10 (1.96–2.26)	<.001
Gender
Female			Reference
Male	0.018	−0.027	1.02 (0.97–1.07)	.440
Household registration
Non-shanghai			Reference
Shanghai	0.588	0.518	1.80 (1.68–1.93)	<.001
Age group
60–69			Reference
70–79	0.165	0.115	1.18 (1.12–1.24)	<.001
≥80	0.394	0.322	1.48 (1.38–1.60)	<.001