Healthcare workers’ willingness to receive COVID-19 booster dose and associated factors in the Democratic Republic of the Congo

Figures & data

Table 1. Socio-demographic characteristics of participants by province.

	Haut-lomami	Kasai oriental	Total
Characteristics	n (%)	n (%)	n (%)	p
Sex
Female	222(43.2)	185(40.1)	407(41.7)	.33
Male	292(56.8)	276(59.9)	568(58.3)
Age interval (in years)
18–55	484(94.2)	438(95.0)	922(94.6)	.56
>55	30(5.8)	23(5.0)	53(5.4)
Marital Status
Married	357(69.5)	289(62.7)	646(66.3)	.001
Single	116(22.6)	154(33.4)	270(27.7)
Divorced	9(1.7)	2(0.4)	11(1.1)
Widowed	23(4.5)	13(2.8)	36(3.7)
Cohabitation or separation	9(1.7)	3(0.7)	12(1.2)
Religion
Christian	474(92.2)	413(89.6)	887(91.0)	.31
Muslim	18(3.5)	21(4.6)	39(4.0)
traditional	16(3.1)	14(3.0)	30(3.1)
atheist	3(0.6)	9(2.0)	12(1.2)
Others	3(0.6)	4(0.9)	7(0.7)
Profession
Doctor	86(16.7)	44(9.5)	130(13.3)	.000
Nurse	203(39.5)	190(41.2)	393(40.3)
midwife	65(12.6)	45(9.8)	110(11.3)
Administrative	65(12.6)	73(15.8)	138(14.2)
Lab technician	52(10.1)	29(6.3)	81(8.3)
Others	43(8.4)	80(17.4)	123(12.6)
Working experience (in years)
<5	205(39.9)	208(45.1)	413(42.4)	.13
5–10	211(41.1)	161(34.9)	372(38.1)
>10	98(19.1)	92(20.0)	190(19.5)

Table 2. Participant’s health, COVID-19 vaccination status and type of vaccine against COVID-19 received by province.

Characteristics	Haut-lomami	Kasai oriental	Total	p
	n (%)	n (%)	n (%)
Have any chronic diseases
Yes	97(18.9)	95(20.6)	192(19.7)	.50
No	417(81.1)	366(79.4)	783(80.3)
chronic diseases
Diabetes	34(6.6)	38(8.2)	72(37.5)	.48
Hypertension	37(7.2)	43(9.3)	80(41.7)	.32
Cancer	5(1.0)	6(1.3)	11(5.7)	.73
Acute or chronic renal failure	2(0.4)	3(0.7)	5(2.6)	.63
Asthma	8(1.6)	11(2.4)	19(9.9)	.44
Others	13(2.5)	10(2.2)	23(12.0)	.54
Have you already received one of the COVID-19 vaccines
Yes	441(85.8)	396(85.9)	837(85.8)	.96
No	73(14.2)	65(14.1)	138(14.2)
Vaccination doses
One	253(56.3)	381(96.0)	634(75.7)	.000
Two	196(43.7)	16(4.0)	203(24.3)
Type of vaccine against COVID-19 received
AstraZeneca	37(8.4)	22(5.6)	59(19.0)	.000
Johnson and Johnson	333(75.5)	355(89.6)	688(82.2)
Moderna	9(2.0)	2(0.6)	11(1.3)
Pfizer	16(3.6)	8(2.0)	24(2.9)
Sinopharm	1(0.2)	0(0.0)	1(0.1)
Sinovac	44(10.1)	9(2.2)	53(6.3)
Spoutnik V	1(0.2)	0(0.0)	1(0.1)

Table 3. Willingness and reasons for being or not willing to take a COVID-19 booster-dose vaccine by province.

Characteristics	Haut-lomami	Kasai oriental	Total	p
	n (%)	n (%)	n (%)
Do you know that the booster dose of COVID-19 vaccine is planned in DRC?
Yes	319(62.1)	345(74.8)	664(68.1)	.0000
No	195(37.9)	116(25.2)	311(31.9)
Are you ready to receive a booster dose of COVID-19 vaccine if available?
Yes	343(66.7)	329(71.4)	672(68.9)	.12
No	171(33.3)	132(28.6)	303(31.1)
If yes, what are the reasons influencing willingness to take the booster dose
Duration of protection	252(73.5)	182(55.3)	434(64.6)	.0002
Employer’s requirement	12(3.5)	27(8.2)	39(5.8)	.009
Government Policy	36(10.5)	23(7.0)	59(8.8)	.11
Suggestion of friends or family	2(0.6)	9(2.7)	11(1.6)	.06
booster dose can prevent serious infections	17(5.0)	36(10.9)	53(7.9)	.004
the booster dose reinforces the effect of the first dose	24(7.0)	52(15.8)	76(11.3)	.0003
If no, what is the major reason why you are not willing or confident to receive a booster dose of COVID-19 vaccine?
One dose of COVID-19 vaccine is already sufficient and a second dose is not needed	91(53.2)	69(52.3)	160(52.8)	.87
The safety of the COVID-19 vaccine is unclear	22(12.9)	11(8.3)	60(19.8)	.21
The efficacy of the COVID-19 vaccine is unclear	18(10.5)	15(11.4)	58(19.1)	.82
Severe disease and ineligibility for vaccination	3(1.8)	3(2.3)	61(20.1)	.75
Believe they are healthy enough to fight COVID-19	5(2.9)	2(1.5)	65(21.5)	.42
COVID-19 in DRC is under control and there is no need to vaccinate	10(5.9)	4(3.0)	18(5.9)	.25
I am concerned about short-term side effects (e.g. fever, etc.)	5(2.9)	9(6.8)	44(14.5)	.19
I am concerned about possible long-term side effects	2(1.2)	7(5.3)	27(8.9)	.08
Believe that the vaccination process is complicated and time consuming	1(0.6)	2(1.5)	18(5.9)	.42
I am against vaccines in general	14(8.2)	10(7.9)	34(11.2)	.85

Table 4. Association between socio-demographic factors and willingness to receive the booster dose.

Socio-demographic factors	Willingness for the booster dose		OR[95% Confidence Interval]	p
	Yes	No
Sex
Male	393(69.2%)	175(30.8%)	1.03[0.78–1.36]	.83
Female	279(68.6%)	128(31.4%)
Age interval (in years)
18–55	636(69.0%)	286(31.0%)	1.05[0.58–1.90]	.87
<55	36(67.9%)	17(32.1%)
Marital Status
Married	456(70.6%)	190(29.4%)	1.26[0.95–1.67]	.12
Not Married	216(65.7%)	113(34.3%)
Region
Kasai oriental	329(71.4%)	132(28.6%)	1.25[0.95–1.65]	.12
Haut-Lomami	340(66.7%)	171(33.3%)
Religion
Christian	612(69.0%)	275(31.0%)	1.04[0.65–1.66]	.88
Not Christian	60(68.2%)	28(31.8%)
Profession
Doctor	100(76.9%)	30(23.1%)	1.59[1.03–2.45]	.03
Not Doctor	572(67.7%)	273(32.3%)
Working experience (in years)
<5	299(72.4%)	114(27.6%)	1.56[1.09–2.25]	.02
5–10	254(68.3%)	118(31.7%)	1.28[0.89–1.85]	.18
>10	119(62.6%)	71(37.4%)

Table 5. Association between participant’s health, perception about COVID-19 booster dose and willingness to receive the booster dose.

Participant’s health, perception about COVID-19 booster dose	Willingness for the booster dose		OR[95% CI]	p
	Yes	No
Have any chronic diseases
Yes	162(84.4%)	30(15.6%)	2.89[1.91–4.38]	.000
No	510(65.1%)	273(34.9%)
Have you already received one of the COVID-19 vaccines
Yes	641(76.6%)	196(23.4%)	11.29[7.34–17.36]	.000
No	31(22.5%)	107(77.5%)
Do you know that the booster dose of COVID-19 vaccine is planned in DRC?
Yes	546(82.2%)	118(17.8%)	6.79[5.03–9.18]	.000
No	126(40.5%)	185(59.5%)
Do you believe that the COVID-19 vaccine is safe?
Yes	653(77.6%)	189(22.4%)	20.73[12.42–34.59]	.000
No	19(14.3%)	114(85.7%)
The COVID-19 booster dose is essential for DRC
Yes	640(82.1%)	140(17.9%)	23.29[15.29–35.47]	.000
No	32(16.4%)	163(83.6%)
Do you think that COVID-19 booster vaccination has adverse reactions?
Yes	528(72.0%)	205(28.0%)	1.75[1.29–2.37]	.000
No	144(59.5%)	98(40.5%)
Do you think the COVID-19 booster vaccine can reduce the spread of COVID-19?
Yes	635(79.6%)	163(20.4%)	14.74[9.87–22.01]	.000
No	37(20.9%)	140(79.1%)
Do you believe that the COVID-19 booster vaccine can reduce the complications associated with COVID-19?
Yes	600(79.5%)	155(20.5%)	7.96[5.71–11.10]	.000
No	72(32.7%)	148(67.3%)
I will encourage my family, friends and loved ones to get the COVID-19 vaccine
Yes	654(77.9%)	185(22.1%)	23.18[13.75–39.06]	.000
No	18(13.2%)	118(86.8%)
Do you think that if everyone in society maintains preventive measures, the COVID-19 pandemic can be eradicated without vaccination?
Yes	486(73.4%)	176(26.6%)	1.89[1.42–2.51]	.000
No	186(59.4%)	127(40.6%)
Do you think that pharmaceutical companies have developed safe and effective COVID-19 vaccines?
Yes	595(78.9%	159(21.1%)	7.00[5.04–9.71]	.000
No	77(34.8%)	144(65.2%)
Do you think that only high-risk people such as health care workers and the elderly with other diseases need a booster dose?
Yes	497(75.5%)	161(24.5%)	2.51[1.89–3.33]	.000
No	175(55.2%)	142(44.8%)

Table 6. Logistic regression analysis exploring factors associated with willingness to take the COVID-19 booster vaccine.

	ORa[95% CI]	p
Have any chronic diseases (yes vs no)	2.95[1.65–5.28]	.000
Have you already received one of the COVID-19 vaccines (yes vs no)	2.72[1.43–5.19]	.002
Do you know that the booster dose of COVID-19 vaccine is planned in DRC (yes vs no)	3.07[1.99–4.74]	.000
The COVID-19 booster dose is essential for DRC (yes vs no)	4.93[2.84–8.57]	.000
Think that if everyone in society maintains preventive measures, the COVID-19 pandemic can be eradicated without vaccination(yes vs no)	1.77[1.17–2.68]	.007
Believe that pharmaceutical companies have developed safe and effective COVID-19 vaccines(yes vs no)	1.75[1.03–2.97]	.038
Consider that only high-risk people such as healthcare workers and older people with other illnesses only need a booster dose(yes vs no)	1.75[1.10–2.81]	.019
People who get COVID-19 are more likely to get serious illness. (yes vs no)	2.13[1.32–3.44]	.002
It is good for the health of the family to receive the booster dose(yes vs no)	5.84[2.83–12.07]	.000
If my family recommends that I receive the booster dose for COVD-19, I will choose to do so(yes vs no)	2.90[1.60–5.23]	.000
Constant	0.000	.016

Figure 1. ROC curve of factors associated with willingness to take the COVID-19 booster vaccine.