Interaction between age and health conditions in the intention to be vaccinated against COVID-19 in Thailand

Figures & data

Table 1. Sociodemographic characteristics of the study cohort

Characteristic	Total n = 862	Percentage (%)
Sex
Male	311	36.1
Female	551	63.9
Age (years)
18–44	532	61.7
45–64	281	32.6
$\ge$65	49	5.7
Household income (Thai baht)
<20,000	130	15.1
20,001–50,000	293	34.0
50,001–80,000	157	18.2
80,001–100,000	88	10.2
100,001–200,000	93	10.8
$\ge$200,000	101	11.7
Education
High school or lower	83	9.6
Bachelor’s degree	390	45.3
Master’s degree	319	37.0
More than Master’s degree	70	8.1
Marital status
Single	480	55.7
Married	341	39.5
Other	41	4.8
Number of family members
1	62	7.2
2–4	559	64.8
>4	241	28.0
Number of health conditions
None	474	55.0
1–2	350	40.6
≥3	38	4.4
Intention to be vaccinated
Likely to get vaccine	479	55.6
Not likely to get vaccine	383	44.4

Table 2. Sociodemographic and health determinants of the intention to be vaccinated against COVID-19

Variable	Total ^a n = 479	Likely to get vaccine (%)	p-Value
Sex
Male	190	61.1	0.014*
Female	289	52.5
Age
18–44	308	57.9	0.053
45–64	151	53.7
$\ge$65	20	40.8
Household Income
Under 20,000	67	51.5	0.504
20,001–50,000	158	53.9
50,001–80,000	88	56.1
80,001–100,000	47	53.4
100,001–200,000	55	59.1
$\ge$200,000	64	63.4
Education
High school or less	40	48.2	0.485
Bachelor’s degree	219	56.2
Master’s degree	178	55.8
More than Master’s	42	60.0
Marital Status
Single	270	56.3	0.471
Married	190	55.7
Others	19	46.3
Family member
1 member	33	53.2	0.927
2–4 members	312	55.8
More than 4 members	134	55.6
Number of Health Risk Conditions
No conditions	268	56.5	0.226
1–2 conditions	195	55.7
3 or more conditions	16	42.1

^aResponses to vaccine intention question was dichotomized to ‘Likely to get vaccine’ as extremely/somewhat likely to get vaccinated (n = 479) versus ‘Not likely to get vaccine’ as unsure/somewhat unlikely/extremely unlikely (n = 383); * p < 0.05.

Table 3. Logistic regression analysis for sex, age, and health conditions for prediction of intention to be vaccinated against COVID-19

	Vaccine intention ^a
Variable	OR [95% CI]	p-Value
Sex
Male	Ref ^a
Female	0.67 [0.50–0.90]	0.008*
Age (years)
18–44	Ref ^a
45–64	0.86 [0.64–1.15]	0.314
$\ge$65	0.58 [0.31–1.06]	0.078
Number of health conditions
None	Ref ^a
1–2	0.93 [0.70–1.24]	0.626
≥3	0.56 [0.28–1.31]	0.106

^aResponses to vaccine intention question was dichotomized to ‘Likely to get vaccine’ as extremely/somewhat likely to get vaccinated (n = 479) versus ‘Not likely to get vaccine’ as unsure/somewhat unlikely/extremely unlikely (n = 383).

*p < 0.05; ^a Reference Category; OR = odds ratio; CI = confidence interval.

Table 4. Estimated marginal means of vaccine acceptance across health conditions and age groups

Age health	Young (18–44 years)	Middle-aged (45–64 years)	Older (≥65 years)
No conditions	3.660	3.586	3.800
1–2 conditions	3.755	3.488	3.478
≥3 conditions	3.636	3.500	2.818

1 = Extremely unlikely to be vaccinated; 5 = Extremely likely to be vaccinated.

Figure 1. Marginal means of COVID-19 vaccine intention (VI) against age groups and health conditions.

Table 5. Rankings of preferences of COVID-19 vaccine type among vaccinated respondents, ranked by frequency of preference given

Preference of vaccine type	Likelihood/rank of getting vaccinated
	Extremely likely (n = 256)	Somewhat likely (n = 223)	Combined (n = 479)
Not enough knowledge and information to make a decision	1st (58.2%)	1st (65.9%)	1st (61.8%)
The vaccine contains the partial genetic code (mRNA) of the virus (Moderna and Pfizer/BioNTech)	2nd (15.6%)	2nd (14.3%)	2nd (15.0%)
The vaccine contains a modified version of the virus (Oxford University/AstraZeneca)	3rd (12.9%)	4th (7.2%)	3rd (10.2%)
The vaccine contains the inactivated virus. (SinoVac)	4th (8.2%)	3rd (9.0%)	4th (8.6%)
The vaccine contains fragments of specific proteins from the virus (Novavax)	5th (5.0%)	5th (3.6%)	5th (4.4%)

Table 6. Rankings of reasons for COVID-19 vaccine hesitancy among non-vaccinated respondents, sorted by age groups

Reason given ^a	Age group/Rank
	Young (n = 84)	Middle-aged (n = 57)	Older (n = 10)
The vaccine might have dangerous side effects	1st (66.7%)	1st (77.2%)	1st (50.0%)
I might be allergic to the vaccine	2nd (46.4%)	2nd (57.9%)	2nd (30.0%)
The vaccine probably would not work	3rd (33.3%)	3rd (29.8%)	3rd (20.0%)
I am at a low risk of infection	5th (13.1%)	4th (21.1%)	1st (50.0%)
The vaccine is too expensive	4th (15.5%)	5th (10.5%)	4th (10.0%)
I prefer developing immunity from infection than immunity through vaccination	7th (7.1%)	6th (8.8%)	2nd (30.0%)
I hate needles and injections	8th (3.6%)	7th (7.0%)	3rd (20.0%)
I am healthy	6th (11.9%)	8th (1.8%)	4th (10.0%)
If I became infected, I would not become seriously ill	7th (7.1%)	8th (1.8%)	2nd (30.0%)
I am already immune from a past COVID-19 infection	9th (0.0%)	9th (0.0%)	3rd (20.0%)

^aThe reasons why respondents hesitated to be vaccinated (n = 151), with one respondent giving more than one reason; Respondents hesitated to be vaccinated (n = 151) included “Somewhat Unlikely” and “extremely Unlikely”.

Table 7. Rankings of reasons for COVID-19 vaccine hesitancy among non-vaccinated respondents, sorted by health condition groups

Reason endorsed ^a	Number of health condition/Rank
	No conditions (n = 82)	1 ≥ 2 conditions (n = 58)	≥3 conditions (n = 11)
The vaccine might have dangerous side effects	1st (75.6%)	1st (60.3%)	1st (72.7%)
I might be allergic to the vaccine	2nd (51.2%)	2nd (50.0%)	2nd (36.4%)
The vaccine probably would not work	3rd (32.9%)	3rd (31.3%)	3rd (18.2%)
I am at a low risk of infection	4th (22.0%)	5th (15.5%)	4th (9.1%)
The vaccine is too expensive	5th (12.2%)	4th (17.2%)	5th (0.0%)
I prefer developing immunity from infection than immunity through vaccination	6th (9.8%)	6th (10.3%)	5th (0.0%)
If I became infected, I would not become seriously ill	7th (8.5%)	7th (5.2%)	5th (0.0%)
I am healthy	8th (7.3%)	6th (10.3%)	5th (0.0%)
I hate needles and injections	9th (4.9%)	7th (5.2%)	3rd (18.2%)
I am already immune from a past COVID-19 infection	10th (0.0%)	8th (3.4%)	5th (0.0%)

^aThe reasons why respondents hesitated to be vaccinated (n = 151), with one respondent giving more than one reason; Respondents hesitated to be vaccinated (n = 151) included “Somewhat Unlikely” and “extremely Unlikely”.