SARS-CoV-2 and influenza vaccine hesitancy during the COVID-19 pandemic in a dynamic perspective

Figures & data

Figure 1. Timeline of in- and out- COVID-19 patients included in the study at 12- and 18-months follow-up.

*Reasons for exclusion: 211 refused to participate; 138 nursing home residents with cognitive decline; 38 lost to follow-up; 81 died.

Figure 2. Interview at 12 months.

Figure 3. Interview at 18 months.

Table 1. Demographic characteristics of the study population.

	N = 479 n (%) mean ± SD	N = 166 n (%) mean ± SD	p-value
Female sex	252 (52.6)	73 (44.0)	0.055
Age	53 ± 15	52 ± 16	0.467
Nationality (n = 457; 162)			0.884
Italian	422 (92.3)	148 (91.4)
European	32 (7.0)	13 (8.0)
Extra European	3 (0.7)	1 (0.6)
Occupation (n = 443; 158)			0.002
Nonpublic contact worker	186 (42.0)	46 (29.1)
Work with public	121 (27.3)	69 (43.7)
Other types	55 (12.4)	18 (11.4)
Retired	81 (18.3)	25 (15.8)
Smoking habits (n = 477; 165)			0.503
Non-smoker	310 (65.0)	115 (69.7)
Current smoker	68 (14.2)	22 (13.3)
Ex-smoker	99 (20.8)	28 (17.0)
Presence of comorbidities	249 (52.0)	70 (42.2)	0.029
Body Mass Index	26.0 ± 4.8	25.9 ± 4.7	0.816

Abbreviations: N/n, number; SD, Standard deviation.

Table 2. Main clinical characteristics of acute SARS-CoV2 infection of the study population.

	N = 479 n (%) median (IQR)	N = 166 n (%) median (IQR)	p-value
Symptomatic COVID-19	413 (86.2)	147 (88.6)	0.444
Hospital admission			0.517
No	340 (71.0)	114 (68.7)
Hospital ward	118 (24.6)	47 (28.3)
ICU	21 (4.4)	5 (3.0)
Symptoms at 12 months	226 (47.2)	81 (48.8)	0.720
Symptoms duration	31 (16–53)	31 (16–53)	0.626
Hospital staying duration	7 (3–11)	7 (3–11)	0.417
COVID-19 positivity duration	19.5 (14–25)	19 (14–24)	0.253

Abbreviations: N, number; COVID-19, COronaVirus Disease 2019; IQR, interquartile range; ICU, Intensive Care Unit. Duration measures are expressed in days.

Table 3. Attitudes toward influenza vaccination and COVID-19 vaccination at 12 months and at 18 months.

	N	%
Vaccinated against flu in 2020 (12 months interview; n = 479)	210	43.8
Likely to take flu vaccine in 2021 (12 months interview; n = 479)	224	46.8
Vaccinated against COVID-19 (12 months interview; n = 479)	132	26.7
Vaccinated against flu in 2021* (18 months interview; n = 166)	30	18.1
Vaccinated against COVID-19 (18 months interview; n = 166)	121	72.9

Abbreviations: N/n, number; COVID-19, COronaVirus Disease 2019.

*Includes patients already vaccinated against influenza in 2021 and patients willing to undertake vaccination before the end of the seasonal campaign.

Table 4. Demographic characteristics of the study cohort according to their attitudes toward influenza vaccination at 12 months and at 18 months.

	Influenza Vaccine 12 Months			Influenza Vaccine 18 Months
	Unlikely	Likely	p-value	Unlikely	Likely	p-value
	n (%)	n (%)		n (%)	n (%)
Gender			0.521			0.743
Male	124 (46.1)	103 (49.0)		77 (56.6)	16 (53.3)
Female	145 (53.9)	107 (51.0)		59 (43.4)	14 (46.7)
Age			<0.001			<0.001
18–40	74 (27.5)	22 (10.5)		38 (27.9)	4 (13.3)
40–60	139 (51.7)	67 (31.9)		70 (51.5)	6 (20.0)
>60	56 (20.8)	121 (57.6)		28 (20.6)	20 (66.7)
Nationality			0.035			0.564
Italian	227 (89.7)	195 (95.6)		119 (90.1)	29 (96.7)
European	23 (9.1)	9 (4.4)		12 (9.1)	1 (3.3)
Extra European	3 (1.2)	0 (0.0)		1 (0.8)	0 (0)
Occupation			<0.001			<0.001
Nonpublic contact worker	111 (45.1)	75 (38.1)		43 (33.6)	3 (10.0)
Work with public	86 (35.0)	35 (17.8)		60 (46.9)	9 (30.0)
Other types	30 (12.2)	25 (12.7)		13 (10.2)	5 (16.7)
Retired	19 (7.7)	62 (31.5)		12 (9.4)	13 (43.3)
Smoking habits			0.192			0.828
Non-smoker	174 (64.9)	136 (65.1)		93 (68.9)	22 (73.3)
Current smoker	44 (16.4)	24 (11.5)		19 (14.1)	3 (10.0)
Ex-smoker	50 (18.7)	49 (23.4)		23 (17.0)	5 (16.7)
Comorbidities			<0.001			0.037
Yes	113 (42.6)	136 (65.1)		52 (39.1)	18 (60.0)
No	152 (57.4)	73 (34.9)		81 (60.9)	12 (40.0)
Body Mass Index	24.7 (22.3–27.7)	25.6 (23.3–28.4)	0.011	25.4 (22.3–7.8)	25.8 (23.1–28.3)	0.332

Abbreviations: n, number; M, median; IQR, interquartile range. Body Mass Index is expressed as M (IQR).

Table 5. Characteristics of acute SARS-CoV-2 infection in the study cohort according to their attitudes toward influenza vaccination at 12 months and at 18 months.

	Influenza Vaccine 12 Months			Influenza Vaccine 18 Months
	Unlikely	Likely	p-value	Unlikely	Likely	p-value
	n (%)	n (%)		n (%)	n (%)
Symptomatic COVID-19			0.581			0.531
Yes	234 (87.0)	179 (85.2)		119 (87.5)	28 (93.3)
No	35 (13.0)	31 (14.8)		17 (12.5)	2 (6.7)
Hospital admission			<0.001			0.012
No	211 (78.4)	129 (61.4)		100 (73.5)	14 (46.7)
Hospital ward	53 (19.7)	65 (31.0)		32 (23.6)	15 (50.0)
ICU	5 (1.9)	16 (7.6)		4 (2.9)	1 (3.3)
Symptoms at 12 months			0.136			0.944
Yes	135 (50.2)	91 (43.3)		67 (49.3)	14 (50.0)
No	134 (49.8)	119 (56.7)		69 (50.7)	14 (50.0)
Symptoms duration	31 (16–53)	31 (16–50)	0.705	31 (16–53)	31 (19–56)	0.995
Hospital staying duration	7 (3–10)	7 (4–12)	0.556	7 (3–8)	7 (3–14)	0.603
COVID-19 positivity duration	19 (14–24)	20 (14–26)	0.279	18 (14–24)	21 (17–26)	0.087

Abbreviations: n, number; COVID-19, COronaVirus Disease 2019; ICU, Intensive Care Unit. Duration measures are expressed in days, median (interquartile range).

Table 6. Reasons for vaccine hesitancy.

Reasons for Vaccine Hesitancy	Influenza 12 Months n/200%)	COVID-19 12 Months n/50%)	Influenza 18 Months n/129%)	COVID-19 18 Months n/45%)
I am concerned about the safety and/or the side effect	13 (6.5)	28 (56.0)	9 (7.0)	8 (17.8)
I am concerned because I don’t think the vaccine will be effective	9 (4.5)	3 (6.0)	30 (23.3)	6 (13.3)
I don’t think I will need the vaccine due to previous infection, health status or age	135 (67.5)	10 (20.0)	72 (55.8)	22 (48.9)
I am against vaccines in general	7 (3.5)	4 (8.0)	4 (3.1)	3 (6.7)
I can’t take any vaccine because of previous vaccine reactions	10 (5.0)	0 (0.0)	4 (3.1)	5 (11.1)
I don’t know	26 (13.0)	5 (10.0)	10 (7.7)	1 (2.2)

Abbreviations: n, number; COVID-19, COronaVirus Disease 2019.

Table 7. Demographic characteristics of the study cohort according to the reason reported regarding vaccine acceptance.

	SARS-CoV-2 Vaccine acceptance 18 Months
	Will to protect themselves and the community	Need to obtain Green Pass	p-value
	n (%)	n (%)
Gender			0.305
Male	50 (55.6)	18 (66.7)
Female	40 (44.4)	9 (33.3)
Age			0.465
18–40	27 (30.0)	8 (29.6)
40–60	33 (36.7)	13 (48.2)
>60	30 (33.3)	6 (22.2)
Nationality			0.395
Italian	83 (93.3)	23 (85.2)
European	5 (5.6)	4 (14.8)
Extra European	1 (1.1)	0 (0.0)
Occupation			0.007
Non public contact worker	18 (20.7)	11 (44.0)
Work with public	39 (44.8)	13 (52.0)
Other types	13 (14.9)	1 (4.0)
Retired	17 (19.5)	0 (0.0)
Smoking habits			0.546
Non-smoker	64 (71.9)	18 (66.7)
Current smoker	12 (13.5)	6 (22.2)
Ex-smoker	13 (14.6)	3 (11.1)
Comorbidities			0.431
Yes	42 (47.2)	10 (38.5)
No	47 (52.8)	16 (61.5)
Body Mass Index			0.695
Value, M (IQR)	25.2 (22.6–28.4)	25.6 (24.2–27.7)
Symptomatic COVID-19			0.291
Yes	79 (87.8)	26 (96.3)
No	11 (12.2)	1 (3.7)
Hospital admission			0.236
No	64 (71.1)	16 (59.3)
Hospital ward	24 (26.7)	9 (33.3)
ICU	2 (2.2)	2 (7.4)
Symptoms at 12 months			0.428
Yes	44 (49.4)	11 (40.7)
No	45 (50.6)	16 (59.3)
Symptoms duration	31 (16–60)	31 (12–39)	0.128
Hospital staying	5.5 (3–9.5)	4 (3–8)	0.919
COVID-19 positivity	19.5 (12–24)	19 (14–22)	0.799

Abbreviations: n, number; COVID-19, COronaVirus Disease 2019; ICU, Intensive Care Unit. Duration measures are expressed in days, median (interquartile range).

Data availability statement

The data presented in this study are available on reasonable request from the corresponding author, M.P. The data are not publicly available due to privacy concerns.