Real-life experience on COVID-19 and seasonal influenza vaccines co-administration in the vaccination hub of the University Hospital of Palermo, Italy

Figures & data

Table 1. COVID-19 and influenza virus vaccines used during the study period.

Vaccine Preventable Disease	Vaccine’s type offered during 2022/23 influenza and COVID-19 vaccination campaigns in Italy and Sicily	Vaccine’s characteristics and indications for different group of population
Influenza	LAIV (Live attenuated quadrivalent influenza vaccine)	Vaccine indicated for subjects aged from 2 to 17 y old by the Ministry of Health
	QIV-cc (Cell Culture based inactivated quadrivalent influenza vaccine)	Vaccine indicated to subjects aged 2 y and older by the Ministry of Health
	QIV-sd (Inactivated quadrivalent influenza vaccine standard dose	Vaccine indicated to subjects aged 6 months and older by the Ministry of Health
	QIV-hd (High dose inactivated quadrivalent influenza vaccine)	Vaccine indicated to subjects aged 60 y and older by Italian Ministry of Health
	QIV-a (Adjuvanted with MF59 Inactivated quadrivalent influenza vaccine)	Vaccine indicated to subjects aged 65 y and older by Italian Ministry of Health
SARS-CoV-2	Protein subunit COVID-19 vaccine	NVX-CoV2373: Vaccine indicated as primary vaccination to people aged 12 y and older and as booster dose to people aged 18 y and older by Italian Ministry of Health
	mRNA COVID-19 vaccines	mRna-1273 bivalent D614G/B.A.1: Vaccine indicated to people aged 12 y and older as booster dose by Italian Ministry of Health
		mRna-bnt162b2 Bivalent D314G/B.A.1: Vaccine indicated to people aged 12 y and older as booster dose by Italian Ministry of Health
		mRna-bnt162b2 Bivalent B.A.4/B.A.5: Vaccine indicated to people aged 5 y and older as booster vaccination by Italian Ministry of Health
		mRna-1273 Bivalent B.A.4/B.A.5: Vaccine indicated to people aged 12 y and older as booster vaccination by Italian Ministry of Health

Table 2. Socio-demographic characteristics and data related to the acceptance of the co-administration of COVID-19 and seasonal influenza vaccines of the 1,263 subjects interviewed at the vaccination hub of the University Hospital of Palermo, Italy.

	n (%)
Gender
− Male	611 (48.4)
− Female	649 (51.4)
−Unspecified	2 (0.16)
Age classes
−18–40	284 (22.5)
−41–59	543 (42.9)
− ≥60	436 (34.5)
Comorbidity
− Yes	343 (27.2)
− No	920 (72.8)
Type of comorbidities
− Cardiac diseases	113 (33.1)
− Haematological diseases	22 (6.4)
− Nephrological diseases	3 (0.88)
− Cancer	24 (7.04)
− Lung diseases	21 (6.16)
− Rheumatic diseases	39 (11.4)
− Others	119 (34.9)
Healthcare professionals (HCPs)
− Yes	507 (40.1)
− No	756 (59.9)
Type of HCPs
− Administrative working in Health Authority	20 (3.94)
− Medical doctor	306 (60.4)
− Medical trainee	67 (13.2)
− Other healthcare workers (nurse, obstretician …)	114 (22.5)
Influenza vaccine administration
− Yes	1020 (80.8)
− No	243 (19.2)
Type of influenza vaccine administered
− aQIV (fluad tetravalente adiuvato)	211 (20.7)
− QIV−e (vaxigrip)	40 (3.92)
− QIV−cc (flucelvax tetra)	647 (63.4)
− QIVhd (efluelda)	122 (11.9)
Sars−CoV2 vaccine administration
− Yes	1241 (98.3)
− No	22 (1.74)
Dose received
− 1	2 (0.16)
− 2	3 (0.24)
− First Booster	159 (12.8)
− Second Booster	1015 (81.8)
− Third Booster	62 (5.0)
Knowledge on co−administration recommendation
− Yes	1107 (87.7)
− No	156 (12.3)
Source of information
− Family/colleagues and/or friends	263 (23.8)
− Printed or online newspapers/TV	298 (26.9)
− GP/pharmacist/pediatrician	272 (24.6)
− Scientific journals/government sites (WHO, CDC etc.)	184 (16.6)
− Social network/web	90 (8.13)
Co−administration of flu and COVID-19 vaccines during 2021/2022 season
− Yes	737 (61.2)
− No	467 (38.8)
Co−administration of flu and COVID-19 vaccines during 2022/2023 season
− Yes	944 (74.7)
− No	319 (25.3)
Main reason for accepting co−administration
− Trust in official recommendations	400 (41.5)
− Physician’s recommendation	48 (4.98)
− Concern about the enhanced protection against the two viruses	180 (18.7)
− Reduction in admissions to the vaccination center	318 (33.0)
− Others (travel, work, comorbilities)	4 (0.42)
− All previous	13 (1.34)
Reasons for refusing flu vaccine (n = 82)
− Lack of Physician’s recommendation	6 (7.32)
− Flu is not a serious illness	29 (35.4)
− Low circulation of influenza virus	30 (36.6)
− I don’t consider the vaccine effective	14 (17.1)
− I don’t consider the vaccine safe	3 (3.66)
Reasons for refusing COVID-19 vaccine (n = 36)
− COVID-19, having received the first booster dose, is not a serious illness	21 (58.3)
− COVID-19’s Omicron variant has no serious and severe effects	7 (19.5)
− I don’t consider the vaccine effective	5 (13.9)
− I don’t consider the vaccine safe	3 (8.33)

Table 3. Univariate (crude OR) and multivariate (adj OR) analysis of factors associated with willingness to receive coadministration of COVID-19 and seasonal influenza vaccines at the vaccination hub of the University Hospital of Palermo, Italy.

Flu and COVID-19 Vaccines co-administration during 2022/2023 season (Yes vs. No)
	Crude OR (95% CI)	p-value	Adj-OR (95% CI)	p-value
Gender
−Female	Ref.	.02	Ref	<.01
− Male	1.45 (1.21–1.87)		1.51 (1.27–1.75)
Age classes
≥60	Ref	<.001	Ref	<.01
−≤ 59	2.56 (1.98–3.85)		2.48 (1.89–3.65)
Comorbidities
− No	Ref	<.001	Ref	.11
− Yes	0.36 (0.28–0.48)		0.72 (0.49–1.07)
HCWs
− No	Ref	<.001	Ref	<.05
− Yes	3.12 (2.32–4.19)		1.66 (1.08–2.57)
Type of HCW
− Trainees, Other HCWs (nurse, obstetrician, …)	Ref	.66
− Medical doctor	1.12 (0.66–1.87)
Knowledge on co-administration recommendation
−No	Ref	.001	Ref	.86
−Yes	1.86 (1.30–2.65)		1.04 (0.63–1.71)
Source of information
− Family/colleagues and/or friends, Social network/web, Printed or online newspapers/TV	Ref	.26
− GP/pharmacist/pediatrician, Scientific journals/government sites (WHO, CDC etc.)	0.90 (0.76–1.41)
Flu and COVID-19 vaccines co-administration during 2021/2022 season
− No	Ref	<.001	Ref	<.05
− Yes	45.6 (28.2–73.8)		41.6 (25.5–67.9)

Figure 1. Acceptance and refusal of flu and COVID-19 vaccines coadministration during 2021/2022 and 2022/2023 seasons at the vaccination hub of the University Hospital of Palermo, Italy.

Data availability statement

The data that support the findings of this study are available from the corresponding author, CC, upon reasonable request.