Potential motivators affecting parental intention in COVID-19 vaccination for children aged 6 months to 4 years: Implications for targeted vaccine interventions in Japan

Figures & data

Table 1. Full list of potential motivators.

[1] The vaccine will help protect child from getting sick from COVID-19

[2] Millions of children have already been safely vaccinated for COVID-19

[3] Researchers determine that vaccinated children are less likely to infect adults

[4] A close friend or family member got their children vaccinated safely

[5] The quickest way for life to return to normal is for most children to get vaccinated

[6] Child’s health care provider recommends they get the vaccine

[7] Public health authorities recommend children get the vaccine

[8] Community leader supports people getting COVID-19 vaccinate for children

Figure 1. Flowchart of the study sample selection. ^aWe contacted parents who have a child under age of six.

Table 2. COVID-19 vaccination behavior and intentions among parents with a child aged 6 months to 4 years.

Vaccine accepting or hesitant category^a		Frequency	(%)	Acceptors	Hesitators	Degree of hesitancy
With child receiving COVID-19 vaccination or vaccination booked		1,519	(12.2)	x
Otherwise
Want my child to receive COVID-19 vaccination		245	(2.0)	x
Inclined to have my child vaccinated		730	(5.8)	x
Not sure about my child’s COVID-19 vaccination		1,883	(15.1)		x	I
Inclined not to have my child vaccinated		3,462	(27.7)		x	II
Do not want my child to receive COVID-19 vaccination		4,663	(37.3)		x	III
Total		12,502	(100.0)

^aThe categories were defined by the following hierarchical questions.

“Has your child received at least one dose of the COVID-19 vaccination?”

“If no, would you want your child to receive COVID-19 vaccination when it is available in your municipality?”

Table 3. Characteristics of the participants.

	All participants	Hesitators
	Analysis set 1	Analysis set 2
	(n = 12,502)	(n = 10,008)
Parent
Age, mean ± SD	36 ±6.1	36 ±6.0
Female, n(%)	8,328 (66.6)	6,849 (68.4)
Number of households, mean ± SD	4 ±1.0	4 ±1.0
Married, n(%)	12,137 (97.0)	9,730 (97.2)
Educational attainment, n(%)
Junior high school	168 (1.3)	137 (1.4)
Senior high school	2,126 (17.0)	1,787 (17.9)
Vocational school	3,153 (25.2)	2,637 (26.3)
University	6,211 (49.7)	4,851 (48.5)
Graduate school	844 (6.8)	596 (6.0)
Annual household income (JPY), n(%)
None	86 (0.7)	63 (0.6)
<2,000,000	394 (3.2)	318 (3.2)
2,000,000–4,000,000	1,582 (12.7)	1,287 (12.9)
4,000,001–600,000	3,151 (25.2)	2,605 (26.0)
6,000,001–8,000,000	2,782 (22.3)	2,212 (22.1)
8,000,001–10,000,000	1,557 (12.5)	1,225 (12.2)
>10,000,000	1,408 (11.3)	1,006 (10.1)
I do not know	1,542 (12.3)	1,292 (12.9)
Job status, n(%)
Employed/self-employed	7,488 (59.9)	5,827 (58.2)
Maternity leave/sick leave	1,537 (12.3)	1,250 (12.5)
Student	32 (0.3)	20 (0.2)
Homemaker	3,333 (26.7)	2,821 (28.2)
Unemployed	112 (0.9)	90 (0.9)
Healthcare worker (Yes), n(%)	1,774 (14.2)	1,372 (13.7)
COVID-19 vaccination status (None), n(%)	1,593 (12.7)	1,461 (14.6)
Current or previous COVID-19 (Yes), n(%)	4,635 (37.1)	3,782 (37.8)
Child (6months to 4years old)
Age, n(%)
0 years old	1,790 (14.3)	1,481 (14.8)
1 year old	2,835 (22.7)	2,309 (23.1)
2 years old	2,598 (20.8)	2,103 (21.0)
3 years old	2,407 (19.3)	1,902 (19.0)
4 years old	2,872 (23.0)	2,213 (22.1)
Female, n(%)	6,029 (48.2)	4,864 (48.6)
Current or previous COVID-19, n(%)	4,420 (35.4)	3,578 (35.8)

Abbreviation: SD, standard deviation.

Table 4. Association between the degree of hesitancy and positive vaccination intention change by potential motivators among vaccine-hesitant parents (analysis set 2; N = 10008).

	Degree of hesitancy^a	More likely to vaccinate	Unadjusted		Adjusted^b
Potential motivators		%	PR	(95%CI)	PR (95%CI)
[1] Protecting child from getting sick	I	58.7	3.12	(2.86, 3.40)	2.82	(2.59, 3.06)
	II	44.9	2.39	(2.20, 2.59)	2.10	(1.93, 2.28)
	III	18.9	1.00	ref	1.00	ref
[2] Safe vaccination of millions of children	I	49.4	3.08	(2.81, 3.39)	2.56	(2.33, 2.81)
	II	38.4	2.38	(2.18, 2.60)	1.96	(1.79, 2.15)
	III	16.0	1.00	ref	1.00	ref
[3] Less likely to infect adults	I	50.3	3.35	(3.04, 3.68)	3.12	(2.83, 3.44)
	II	34.0	2.26	(2.06, 2.48)	2.12	(1.92, 2.34)
	III	14.9	1.00	ref	1.00	ref
[4] A close friend or family’s children got vaccine safely	I	42.8	3.31	(2.99, 3.67)	2.94	(2.63, 3.28)
	II	33.3	2.61	(2.37, 2.87)	2.26	(2.03, 2.51)
	III	12.6	1.00	ref	1.00	ref
[5] Quickest way to return to normal	I	43.8	3.51	(3.17, 3.89)	3.00	(2.70, 3.34)
	II	29.5	2.36	(2.14, 3.17)	2.05	(1.84, 2.28)
	III	12.4	1.00	ref	1.00	ref
[6] Recommendation of child’s healthcare provider	I	40.4	3.25	(2.92, 3.61)	2.69	(2.41, 3.00)
	II	31.3	2.53	(2.30, 2.79)	2.00	(1.80, 2.22)
	III	12.2	1.00	ref	1.00	ref
[7] Recommendation of the public health authorities	I	24.4	4.48	(3.86, 5.20)	3.60	(3.06, 4.23)
	II	12.9	2.35	(2.02, 2.72)	2.01	(1.71, 2.36)
	III	5.4	1.00	ref	1.00	ref
[8] Recommendation of the community leader	I	20.3	4.19	(3.58, 4.91)	3.38	(2.84, 4.07)
	II	10.4	2.14	(1.82, 2.51)	1.87	(1.57, 2.24)
	III	4.7	1.00	ref	1.00	ref

Abbreviations: CI, confidence interval; PR, probability ratio.

^aI = Not sure about my child COVID-19 vaccination; II = Inclined not to have my child vaccinated; III = Do not want my child to receive the COVID-19 vaccine.

^bAdjusted for parent’s gender, educational attainment, household income per year, parent’s COVID-19 vaccination status, child’s age, fear of COVID-19 scale score, and work type.

Figure 2. Association between potential motivators and vaccination intention changes among vaccine-hesitant parents (analysis set 2). Eight yes/no answers for vaccination intention change by potential motivators were pooled across 10,008 parents, resulting in 80,064 observations. PRs (95% CIs) were determined using generalized estimating equations for a log-linear Poisson regression model, clustering eight answers within the same parents. The horizontal axis is the log scale. Abbreviations: CI, confidence interval; PR, probability ratio.

Data availability statement

Raw data were generated at Keio University. Derived data supporting the findings of this study are available from the corresponding author Y.K. on reasonable request.