Assessing the vaccine effectiveness for hand, foot, and mouth disease in Guangzhou, China: a time-series analysis

Figures & data

Figure 1. Vaccination rates and HFMD cases in Guangzhou, China, 2016–2018

Footnotes: The denominator was the permanent population.

Table 1. Number (%) of HFMD cases and EV71 vaccinations in Guangzhou, China, 2016–2018

	HFMD cases	One-dose vaccination	Two-dose vaccination	Births
Total	174002 (100.00)	107850 (100.00)	408664 (100.00)	4250600 (100.00)
Year
2016	56887 (32.69)	7209 (6.68)	25510 (6.24)	1294500 (30.45)
2017	71812 (41.27)	28419 (26.35)	165529 (40.50)	1516300 (35.67)
2018	45303 (26.04)	72222 (66.97)	217625 (53.25)	1439800 (33.87)
Age
0+	22449 (12.90)	23682 (21.96)	70492 (17.25)
1+	55423 (31.85)	40603 (37.65)	191569 (46.88)
2+	33481 (19.24)	22863 (21.20)	95487 (23.37)
3+	33288 (19.13)	13102 (12.15)	34687 (8.49)
4+	19540 (11.23)	6463 (5.99)	14180 (3.47)
5+	9821 (5.64)	1137 (1.05)	2249 (0.55)
Sex
Male	105163 (60.44)	57528 (53.34)	216581 (53.00)
Female	68839 (39.56)	50322 (46.66)	192083 (47.00)
Virus
EV71	1120 (0.64)
CVA16	933 (0.54)
Others	2771 (1.59)
Unserotyped	169178 (97.23)

Table 2. Ratios of HFMD cases for high to low EV71 vaccination rate districts in Guangzhou, China, 2016–2018

Dose	Vaccination rate	Total	After	Proportion(%)	Ratio(95%CI)	P value
One-dose	High	91497	60670	66.31	0.969(0.963,0.976)	<0.001
	Low	82505	56445	68.41
Two-dose	High	71892	47099	65.51	0.955(0.949,0.962)	<0.001
	Low	102110	70016	68.57

Footnotes: Total: total number of HFMD cases; After: number of HFMD cases from 2017–2018, after introduction of the EV71 vaccine.

Table 3. Associations between two-dose EV71 vaccination rate and HFMD cases in Guangzhou, China, 2016–2018

	β(95%CI)	P value	Effectiveness	Adjusted R^2
Total	−0.009(−0.020, 0.001)	0.094	NS	0.82
Age (years)
0+	−0.02(−0.102, 0.061)	0.630	NS	0.86
1+	−0.005(−0.012, 0.002)	0.147	NS	0.82
2+	−0.007(−0.013, 0.000)	0.071	NS	0.81
3+	−0.009(−0.018, −0.001)	0.046	59.93	0.79
4+	−0.013(−0.029, 0.004)	0.147	NS	0.79
5+	−0.017(−0.047, 0.012)	0.262	NS	0.85
Sex
Male	−0.01(−0.020, 0.001)	0.086	NS	0.82
Female	−0.009(−0.019, 0.002)	0.108	NS	0.82
Virus
EV71	−0.014(−0.024,-0.004)	0.012	75.17	0.79
CVA16	0.009(−0.005,0.022)	0.219	NS	0.73
Other	−0.013(−0.021,-0.006)	0.002	73.76	0.93

Footnotes: β: the regression coefficient of vaccination rates; NS: not statistically significant; Effectiveness: the effectiveness were calculated at a 100% vaccination rate.

Figure 2. Vaccine effectiveness as a function of two-dose vaccination rate in statistically significant subgroups

Figure 3. Observed and fitted HFMD cases in Guangzhou, China, 2016–2018

Data availability

The cases data and vaccination data are available from Guangzhou, China CDC (http://www.gzcdc.org.cn/), which were used under license and not publicly available.