Analysis of adverse events following immunization in Zhejiang, China, 2019: a retrospective cross-sectional study based on the passive surveillance system

Figures & data

Figure 1. AEFI records in the national AEFI surveillance system database, 2019, by month of onset of AEFI. (a): the total number of AEFI reported in 2019 with its reporting rate; (b): the number of serious AEFI reported in 2019 with its reporting rate

Table 1. Serious AEFI and non-serious AEFI records in the national AEFI surveillance system database, 2019, by age group

Age group	Administrated doses	AEFI		χ^2	P	Serious AEFI		Non-serious AEFI
		No.	Rate			No.	Rate	No.	Rate
0	4,806,327	5220	108.61	355.87	<0.001	55	1.14	5165	107.46
1	5,859,698	3982	67.96			17	0.29	3965	67.67
2–4	5,703,993	2104	36.89			22	0.39	2082	36.50
5–7	1,728,374	944	54.62			8	0.46	936	54.15
8–14	512,867	136	26.52			1	0.19	135	26.32
15–59	1,969,842	386	19.60			9	0.46	377	19.14
≥60	2,510,300	307	12.23			15	0.60	292	11.63
Total	23,091,401	13079	56.64			127	0.55	12952	56.09

Rate:/100000 doses.

Table 2. Serious AEFI and non-serious AEFI records in the national AEFI surveillance system database, 2019, by city

City	Administrated doses	AEFI		Serious AEFI		Non-serious AEFI
		No.	Rate	No.	Rate	No.	Rate
Hangzhou	4,587,656	3059	66.68	33	0.72	3026	65.96
Ningbo	2,958,024	1688	57.07	11	0.37	1677	56.69
Wenzhou	3,293,947	1850	56.16	13	0.39	1837	55.77
Jiaxing	1,747,068	1031	59.01	18	1.03	1013	57.98
Huzhou	1,255,111	571	45.49	2	0.16	569	45.33
Shaoxing	1,630,918	781	47.89	4	0.25	777	47.64
Jinhua	2,947,299	1631	55.34	17	0.58	1614	54.76
Quzhou	763,382	462	60.52	3	0.39	459	60.13
Zhoushan	286,709	103	35.92	3	1.05	100	34.88
Taizhou	2,743,285	1466	53.44	22	0.80	1444	52.64
Lishui	878,002	437	49.77	1	0.11	436	49.66
Total	23,091,401	13079	56.64	127	0.55	12952	56.09

Rate:/100000 doses.

Table 3. Category of AEFI records in the national AEFI surveillance system database, 2019, by city

City	Administrated doses	Vaccine product-related reaction(minor)		Vaccine product-related reaction(severe)		Immunization error		Coincidental event		Anxiety reaction		Total
		No.	Rate	No.	Rate	No.	Rate	No.	Rate	No.	Rate	No.	Rate
Hangzhou	4,587,656	2666	58.11	322	7.02	0	-	61	1.33	10	0.22	3059	66.68
Ningbo	2,958,024	1604	54.23	56	1.89	1	0.03	25	0.85	2	0.07	1688	57.07
Wenzhou	3,293,947	1602	48.63	207	6.28	0	-	38	1.15	3	0.09	1850	56.16
Jiaxing	1,747,068	778	44.53	205	11.73	0	-	46	2.63	2	0.11	1031	59.01
Huzhou	1,255,111	469	37.37	86	6.85	0	-	14	1.12	2	0.16	571	45.49
Shaoxing	1,630,918	578	35.44	184	11.28	0	-	14	0.86	5	0.31	781	47.89
Jinhua	2,947,299	1540	52.25	71	2.41	0	-	20	0.68	0	-	1631	55.34
Quzhou	763,382	363	47.55	80	10.48	0	-	19	2.49	0	-	462	60.52
Zhoushan	286,709	79	27.55	14	4.88	0	-	10	3.49	0	-	103	35.92
Taizhou	2,743,285	1181	43.05	237	8.64	0	-	41	1.49	7	0.26	1466	53.44
Lishui	878,002	411	46.81	14	1.59	3	0.34	9	1.03	0	-	437	49.77
Total	23,091,401	11271	48.81	1476	6.39	4	0.02	297	1.29	31	0.13	13079	56.64

Rate:/100000 doses.

Table 4. Vaccine types listed as “suspected” in records of AEFI in the national AEFI surveillance system database, 2019

Suspected vaccine	Administrated doses	AEFI records		AEFI with one suspected vaccine only		Severe AEFI		Vaccine product-related reaction		Severe vaccine product-related reaction
		No.	Rate	No.	Rate	No.	Rate	No.	Rate	No.	Rate
BCG	574,151	85	14.80	61	10.62	3	0.52	33	5.75	1	0.17
DTP	2,071,285	2751	132.82	2211	106.75	5	0.24	94	4.54	5	0.24
DT	650,291	676	103.95	513	78.89	7	1.08	12	1.85	5	0.77
bOPV	992,836	201	20.25	95	9.57	6	0.60	27	2.72	2	0.20
IPV	993,298	138	13.89	81	8.15	2	0.20	14	1.41	1	0.10
MMR	1,409,081	1775	125.97	734	52.09	22	1.56	614	43.57	12	0.85
HepB	2,428,086	451	18.57	235	9.68	1	0.04	20	0.82	1	0.04
HepA-l	630,772	139	22.04	106	16.80	4	0.63	28	4.44	2	0.32
MPV-a	774,489	458	59.14	366	47.26	5	0.65	39	5.04	3	0.39
MPV-ac	1,218,761	307	25.19	243	19.94	2	0.16	56	4.59	2	0.16
JEV-l	1,295,107	481	37.14	347	26.79	5	0.39	60	4.63	3	0.23
HepA-i	256,491	66	25.73	57	22.22	0	-	3	1.17	0	-
JEV-i	375,880	301	80.08	265	70.50	1	0.27	20	5.32	1	0.27
MenV-acyw135	199,246	82	41.16	70	35.13	2	1.00	20	10.04	2	1.00
TIV	782,658	569	72.70	540	69.00	14	1.79	64	8.18	6	0.77
QIV	289,875	128	44.16	120	41.40	0	-	5	1.72	0	-
VZV	1,333,588	382	28.64	345	25.87	4	0.30	62	4.65	2	0.15
Hib	495,604	225	45.40	187	37.73	0	-	14	2.82	0	-
RV5	488,753	82	16.78	77	15.75	0	-	12	2.46	0	-
PPV23	330,902	605	182.83	525	158.66	6	1.81	18	5.44	4	1.21
PCV13	558,620	839	150.19	838	150.01	6	1.07	39	6.98	3	0.54
RRV	2,134,878	313	14.66	236	11.05	9	0.42	54	2.53	6	0.28
DTP-IPV-Hib	535,769	599	111.80	591	110.31	4	0.75	22	4.11	4	0.75
DTP-Hib	131,967	563	426.62	549	416.01	3	2.27	12	9.09	1	0.76
MCV-ac	438,663	195	44.45	164	37.39	2	0.46	20	4.56	0	-
Hib-MCV-ac	114,256	39	34.13	30	26.26	1	0.88	3	2.63	1	0.88
EV71	977,843	435	44.49	426	43.57	6	0.61	70	7.16	3	0.31
HPV2	57,210	26	45.45	26	45.45	0	-	4	6.99	0	-
HPV4	300,219	50	16.65	49	16.32	1	0.33	12	4.00	1	0.33
HPV9	202,418	67	33.10	67	33.10	2	0.99	7	3.46	1	0.49
OCV	48,404	8	16.53	8	16.53	0	-	2	4.13	0	-

Rate:/100000 doses.

Table 5. Clinical diagnosis of AEFI in the national AEFI surveillance system database, 2019

Clinical diagnosis	No. of AEFI records						Rate
	Vaccine product-related reaction(minor)	Vaccine product-related reaction(severe)	Immunization error	Coincidental event	Anxiety reaction	Total
Aseptic abscess	0	5	0	0	0	5	0.02
Febrile convulsions	0	18	0	9	0	27	0.12
Anaphylactic shock	0	5	0	0	0	5	0.02
Urticaria	0	284	0	7	0	291	1.26
Scarlet fever rash	0	67	0	0	0	67	0.29
Maculopapular rash	0	145	0	3	0	148	0.64
Allergic purpura	0	9	0	1	0	10	0.04
Thrombocytopenic purpura	0	19	0	8	0	27	0.12
Arthus reaction	0	1	0	0	0	1	0.00
Angioedema	0	33	0	0	0	33	0.14
Laryngeal edema	0	2	0	0	0	2	0.01
Other allergic reactions	0	44	0	1	0	45	0.19
Polyneuritis	0	0	0	1	0	1	0.00
Guillain Barre Syndrome	0	0	0	3	0	3	0.01
Epilepsy	0	0	0	4	0	4	0.02
Encephalitis and meningitis	0	1	0	2	0	3	0.01
Vaccine-associated paralytic polio	0	1	0	0	0	1	0.00
BCG-associated lymphadenitis	0	15	0	0	0	15	0.06
Abscess	0	13	0	0	0	13	0.06
Lymphagitis and lymphadenitis	0	3	0	1	0	4	0.02
Cellulitis	0	3	0	0	0	3	0.01
Septicemia	0	0	0	1	0	1	0.00
Sepsis	0	0	0	2	0	2	0.01
Syncope	0	0	0	0	6	6	0.03
Hysteria	0	0	0	0	1	1	0.00
Acute disseminated encephalomyelitis	0	2	0	0	0	2	0.01
Allergic rash	0	767	0	13	0	780	3.38
Fever/redness/induration	11,271	0	0	2	0	11,273	48.82
Other reaction	0	39	4	239	24	306	1.33

Rate:/100000 doses.

Table 6. The interval between AEFI onset and immunization in the national AEFI surveillance system database, 2019

The interval between AEFI onset and immunization	AEFI		Serious AEFI		Vaccine product-related reaction(severe)
	No.	%	No.	%	No.	%
0–1d	11,839	90.52	85	66.93	1288	87.26
2–3d	771	5.89	13	10.24	81	5.49
4–7d	226	1.73	6	4.72	41	2.78
8–14d	101	0.77	8	6.30	25	1.69
≥15d	142	1.09	15	11.81	41	2.78