Vaccination experiences of premature children in a retrospective hospital-based cohort in a Chinese metropolitan area

Figures & data

Table 1. Baseline characteristics between included and excluded premature children

	Included children n = 1124		Excluded children n = 426
	n	(%)	n	(%)	P value
Gender
Male	623	(55.4)	250	(58.7)	.248
Female	501	(44.6)	176	(41.3)
Year of birth
2010–2016	206	(18.3)	74	(17.4)	.958
2017	270	(24.0)	104	(24.4)
2018	361	(32.1)	135	(31.7)
2019	287	(25.5)	113	(26.5)
Month of age at consultation
0–18	1035	(92.1)	377	(88.5)	.027
>18	89	(7.9)	49	(11.5)
Gestational weeks
<28	90	(8.1)	54	(12.8)	.017
28–31^+6	368	(33.2)	140	(33.2)
32–37^+6	649	(58.6)	228	(54.0)
Vaccination before assessment by VCC
Had been vaccinated normally	114	(10.1)	45	(10.6)	.807
Had delayed certain/all vaccines	1010	(89.9)	381	(89.4)
VCC recommendation
Normal vaccination	393	(35.0)	175	(41.1)	.026
Delayed vaccination	731	(65.0)	251	(58.9)
Birth weight (g)
Mean (SD)	1799.4 (21.2)		1808.7 (33.8)		.815

VCC, vaccination consultation clinic at the Children’s Hospital of Fudan University.

Table 2. Vaccination experiences of live attenuated vaccines included in the expanded program of immunization in premature children

	Across three groups*	Delayed duration of time in children with a recommendation of normal vaccination (days), P50 (P25, P75)			Delayed duration of time in children with a recommendation of delayed vaccination (days), P50 (P25, P75)
	P value	Vaccinated before the assessment	Vaccinated after the assessment	P value **	Vaccinated before the assessment	Vaccinated after the assessment	P value **
Bacillus Calmette-Guerin vaccine (BCG)	<.001	59 (24, 123)	33 (14, 101)	.19	49 (6, 77)	135 (35, 254)	<.001
Measles-rubella vaccine (MR)	<.001	0 (0, 47)	0 (0, 31)	.468	0 (0, 47)	1 (0, 86)	.002
Measles-mumps-rubella vaccine (MMR) ***	<.001	0 (0, 76)	0 (0, 108)	.574	0 (0, 0)	0 (0, 36)	.048

*The comparison was conducted between the recommendations of normal vaccination and delayed vaccination across three groups (vaccinated before the assessment, vaccinated after the assessment, and not ever vaccinated in this study) using chi-square test.

**Mann-Whitney test was employed.

***Delayed duration of time in the vaccination of MMR was presented as P₅₀ (P_25, P₉₀) due to limited sample size.

Table 3. Vaccination experiences of inactivated vaccines included in the expanded program of immunization in premature children

	Across three groups*	Delayed duration of time in the infants with a recommendation of normal vaccination (days), P50 (P25, P75)			Delayed duration of time in the infants with a recommendation of delayed vaccination (days), P50 (P25, P75)
	P value	Vaccinated before the assessment	Vaccinated after the assessment	P value **	Vaccinated before the assessment #	Vaccinated after the assessment	P value **
Hepatitis B vaccine (HepB)	-	49 (8, 93)	8 (2, 23)	<.001	-	-	-
Polio vaccine (PV)	-	0 (0, 44)	14 (0, 38)	<.001	-	-	-
Diphtheria tetanus pertussis vaccine (DTaP)	.097	0 (0, 29)	15 (0, 50)	<.001	-	247 (75, 362)	.001
Meningococcal serogroup A polysaccharide vaccine (MenA)	.086	0 (0, 50)	11 (0, 47)	.647	-	238 (33, 408)	.011
Japanese encephalitis vaccine (JEV)	.373	0 (0, 45)	0 (0, 65)	.617	-	154 (55, 237)	.003
Hepatitis A vaccine (HepA)***	-	0 (0, 151)	0 (0, 45)	.552	-	-	-

*The comparison was conducted between the recommendations of normal vaccination and delayed vaccination across three groups (vaccinated before the assessment, vaccinated after the assessment, and not ever vaccinated in this study) using Fisher’s exact test. For HepB, PV, and HepA, there was no recommendation of delayed vaccination.

**Mann-Whitney test was employed.

***Delayed duration of time in the vaccination of HepA was presented as P50 (P25, P90) due to limited sample size.

^#For HepB, PV, and HepA, there was no recommendation of delayed vaccination. For DTaP, MenA, and JEV, there was no vaccination before the assessment in children with a recommendation of delayed vaccination; thus, P value in the last column was compared between those vaccinated after the assessment with a recommendation of normal vaccination and those with a recommendation of delayed vaccination.

Figure 1. Vaccination experiences of non-EPI vaccines before and after the assessment by the Vaccination Consultation Clinic (VCC) at the Children’s Hospital of Fudan University. In each panel, the height of colorful bars (left side) and triangles (right side) indicated the number of premature children in each group. Before the assessment, premature children were classified into four groups, demonstrating vaccination status on the left side of each bar, including “vaccinated,” “under RAV (recommended age of vaccination),” “within RAV,” and “beyond RAV.” After the assessment, on the right side of each triangle, premature children were classified as “vaccinated” and “beyond RAV” in the vaccination of PCV13 (panel a), DTaP-IPV/Hib (b), DTaP-Hib (c), and Hib (d); an additional status “within RAV” in EV-71 (e) and RotV (f); and another status “under RAV” in VarV (g). The flows from left bars to right triangles indicted the number of premature children who changed or remained their vaccination status before and after the assessment by VCC.

Table 4. Incidence of notifiable vaccine-preventable diseases in included and excluded premature children

	Included children (n = 1124)				Excluded children (n = 426)
	No. case	Person-years	Incidence density (/100,000 person-years)	95%CI (/100,000 person-years)	No. case	Person-years	Incidence density (/100,000 person-years)	95%CI (/100,000 person-years)
Pertussis	1	2853.1	35.0	−33.6, 103.7	3	1047.8	286.3	−37.2, 609.9
Varicella	1	2852.0	35.1	−33.7, 103.8	1	1053.9	94.9	−91.0, 280.8

Table 5. Incidence of notifiable vaccine-preventable diseases in included children

	No. case	Person-years	Incidence density (/100,000 person-years)	95%CI (/100,000 person-years)
Pertussis
Unvaccinated	1	577.3	173.2	−166.0, 512.4
Vaccinated	0	2275.9	0	0, 0
Varicella
Unvaccinated	1	1338.4	74.7	−71.7, 221.1
Vaccinated	0	1513.6	0	0, 0