Demand and motivation for influenza vaccination among healthcare workers before and during the COVID-19 era: a cross-sectional survey

ABSTRACT

Protection of healthcare workers (HCWs) against influenza is essential for patient health and a functional health system. The study aimed to analyze the demand for seasonal influenza vaccination (SIV) among various groups of HCWs in a tertiary care hospital before and during the COVID-19 pandemic and to identify their motives for this season’s SIV. Before this influenza season (2020/21), the hospital management offered free SIV to all HCWs and promoted it on the internal network. Out of 4,167 HCWs, 630 HCWs expressed interest in SIV and were vaccinated in the hospital. They filled in a total of 603 self-administered pen-and-paper questionnaires. The mean age of the respondents (374 females and 229 males) was 45 ± 12 years. Physicians accounted for 48% of the vaccinated persons but for only 24% (p < .001) of all HCWs to whom SIV was offered. Only 16% of respondents vaccinated this year also received SIV before the last season (2019/20), with the proportion of physicians (19%) being statistically significantly higher than that of non-physicians (13%, p = .045) and the proportion of chronically ill HCWs (22%) being higher than that of healthy individuals (13%, p = .004). Most frequently, respondents’ motivation to get vaccinated this year was self-protection (61%), that is concerns about contracting influenza together with COVID-19 or alone, followed by family protection (58%) and patient protection (53%). In conclusion, COVID-19 contributed to an increased demand for SIV among HCWs and the threat of contracting it together with influenza was the most frequent motive.

Introduction

Seasonal influenza occurs worldwide and spreads very quickly in the population, especially in crowded circumstances. In the northern hemisphere, annual influenza epidemics occur during autumn and winter, affecting approximately 5–15% of the population. Globally, these annual epidemics are estimated to result in about 3 to 5 million cases of severe illness and about 290,000 to 650,000 respiratory deaths (44,000 in the WHO European Region).^1,2

Seasonal influenza vaccination (SIV) is a safe and the most effective measure to prevent severe disease caused by influenza. In the WHO European Region, SIV coverage of the general population varies considerably, by tens of per cent, between countries.³ The Czech Republic belongs to low-coverage countries, with 5–6% of the general population receiving SIV every year.⁴ Of special interest is SIV coverage among healthcare workers (HCWs) as they are at high risk of contracting the infection from their patients and disseminating it. Moreover, HCWs’ sickness absences may also threaten health care systems.⁵ SIV coverage among HCWs remains below 40% in most European countries (once again with considerable differences). Only 10–15% of Czech HCWs are estimated to have undergone SIV during past influenza seasons.⁴

Influenza vaccination uptake depends on several highly context-specific factors. In less-resourced countries, where influenza may not be considered a high-priority disease, low coverage is a consequence of limited vaccine procurement.³ Where vaccines are more widely available, for example in the WHO European Region, low or dropping influenza vaccination uptake may be attributed to different factors, including a lack of confidence in the vaccine, a low perceived need for SIV, a lack of recommendation from HCWs or out-of-pocket costs to receive SIV.³ With regard to HCWs’ vaccination and its implementation, reimbursement and support, considerable differences between countries may be observed, from free and fully available SIV to the same rules being applied to both HCWs and the general population, that is, free SIV for high-risk and elderly persons. This was also the case during the previous influenza season in the Czech Republic. Vaccination of the general population is usually supported individually by health insurance companies.^4,6

In the light of the current COVID-19 pandemic, SIV before the 2020/21 influenza season in the northern hemisphere is taking on a whole new dimension. The perceived immediate risk may change the original structure of HCWs’ motivation to be vaccinated. Risk perception is one of the critical factors in determining health-seeking behavior. Many studies have suggested that disease risk perceptions are a vital determinant of health behavior.^7,8 Concerns about the COVID-19 pandemic coinciding with the influenza season have significantly affected the importance of SIV for achieving the greatest possible protection of the population, including HCWs.⁹

The study aimed to analyze the demand for SIV among various groups of HCWs in a tertiary care hospital before and during the COVID-19 pandemic and to identify their motives for this season’s SIV.

Materials and methods

In previous years, SIV of HCWs in the study hospital reflected the general situation in the Czech Republic as described above and no particular measures were in place to improve the coverage. In the study hospital, SIV had long been available for a charge at a vaccination center of the Department of Occupational Medicine, with the annual demand not exceeding 50 doses. There were no campaigns to promote SIV coverage at the hospital level. Before the 2020/21 influenza season, however, the hospital management offered free SIV to all 4,167 HCWs (994 physicians and 3,173 non-physicians). The employees were encouraged to get vaccinated through information on the hospital internal network including available scientific data on the benefits of SIV, both generally and during the COVID-19 pandemic.^10,11 As a result, 630 HCWs expressed interest in SIV and the same number of vaccine doses (Influvac Tetra by Abbott and Vaxigrip Tetra by Sanofi Pasteur) were provided. The vaccination was performed by employees of the Department of Occupational Medicine during September and October 2020.

The participation in this cross-sectional anonymous survey was voluntary. During the post-vaccination observation period, all 630 HCWs were asked to fill in a self-administered pen-and-paper questionnaire and drop it in a box provided. The questionnaire, created by the authors, contained mostly closed-ended questions on respondents’ personal information including age, sex and job type (i.e. physician or non-physician), previous influenza vaccination (i.e. in the 2019/20 season and at any time beforehand), health status and treatment (i.e. receiving therapy for chronic disease; a “yes” answer was followed by an open-ended question on the disease), as well as eight multiple-choice options concerning the motives for SIV (Table 1).

Table 1.

Motives to get vaccinated against influenza (multiple-choice options) and the frequency of their selection

	Option 1	Option 2	Option 3	Option 4	Option 5	Option 6	Option 7	Option 8
	Concerns about contracting influenza alone	Concerns about possibly contracting influenza and COVID-19 at the same time	Concerns about a shortage of vaccines in the facility where I was vaccinated in the past	Concerns about a lower income during a temporary sick leave	Trying not to spread influenza while doing my job (to patients)	Trying to protect my family	The opportunity to be vaccinated directly at my workplace	The vaccination is free for healthcare workers
Total	271 (44.9%)	366 (60.7%)	19 (3.2%)	62 (10.3%)	319 (52.9%)	349 (57.9%)	290 (48.1%)	128 (21.2%)
Respondent subgroups
Females	181 (48.4%)*	242 (64.7%)*	10 (2.7%)	33 (8.8%)	203 (54.3%)	228 (61%)*	183 (48.9%)	76 (20.3%)
Males	90 (39.3%)	124 (54.1%)	9 (3.9%)	29 (12.7%)	116 (50.7%)	121 (52.8%)	107 (46.7%)	52 (22.7%)
Physicians	116 (40.1%)*	173 (59.9%)	10 (3.5%)	24 (8.3%)	164 (56.7%)	166 (57.4%)	136 (47.1%)	57 (19.7%)
Non-physicians	155 (49.4%)	193 (61.5%)	9 (2.9%)	38 (12.1%)	155 (49.4%)	183 (58.3%)	154 (49%)	71 (22.6%)
Healthy	162 (39.1%)**	246 (59.4%)	10 (2.4%)	40 (9.7%)	224 (54.1%)	239 (57.7%)	186 (44.9%)*	85 (20.5%)
Chronically ill	109 (57.7%)	120 (63.5%)	9 (4.8%)	22 (11.6%)	95 (50.3%)	110 (58.2%)	104 (55%)	43 (22.8%)
<44 years of age	124 (41.6%)	179 (60.1%)	9 (3%)	33 (11.1%)	171 (57.4%)*	178 (59.7%)	151 (50.7%)	72 (24.2%)
≥44 years of age	147 (48.2%)	187 (61.3%)	10 (3.3%)	29 (9.5%)	148 (48.5%)	171 (56.1%)	139 (45.6%)	56 (18.4%)
Vaccinated in 2019/2020	68 (70.8%)**	44 (45.8%)*	7 (7.3%)*	8 (8.3%)	54 (56.3%)	64 (66.7%)	47 (49%)	19 (19.8%)
Vaccinated at any time before 2019/20	143 (56.3%)**	143 (56.3%)	12 (4.7%)	28 (11%)	133 (52.4%)	155 (61%)	125 (49.2%)	57 (22.4%)
Never vaccinated	128 (36.7%)	223 (63.9%)	7 (2%)	34 (9.7%)	186 (53.3%)	194 (55.6%)	165 (47.3%)	71 (20.3%)

Statistical significance of differences between subgroups: *p<0.05, **p<0.001, otherwise insignificant; both vaccinated in 2019/2020 and vaccinated at any time in the past compared to never vaccinated.

Using Maslow’s hierarchy of needs as the theoretical model, a pool of possible motives regarding SIV was developed using the existing literature, expert evaluation and modification, and pilot testing of the questionnaire.¹² Two (Options 1 and 2) focused directly on meeting physiological needs (self-protection), another two (Options 3 and 4) on the need for safety (concerns about lack), one (Option 5) on the need for recognition and self-realization (patient protection) and one (Option 6) on family protection. The last two (Options 7 and 8) dealt with organizational and financial benefits.

The collected data were statistically analyzed in IBM SPSS Statistics 22 using methods of descriptive statistics and the chi-square test. The level of statistical significance was set at p = .05. The study was approved by the Ethics Committee of the University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacký University Olomouc (reference no. 157/20).

Results

Vaccination demand

After all vaccine doses (n = 630) were administered, a total of 603 completed questionnaires were obtained, a response rate of more than 95%. Basic characteristics of respondents receiving vaccination this year (2020/21), with regard to the previous influenza season, are shown in Table 2. The mean age of respondents was 44.5 years (standard deviation, 12.0). There were 374 females and 229 males; 289 physicians and 314 non-physicians. Only 15.9% of respondents vaccinated this year also received SIV before the last season. For as many as 349 respondents (57.9%), this was the first SIV in their life.

Table 2.

Comparison of vaccination received this and last influenza season

	2020/2021	Of whom in 2019/2020
No. of respondents	603	96 (15.9%)
Respondent subgroups
Females	374 (62.0%)	53 (14.2%)
P-value		0.134
Males	229 (38.0%)	43 (18.8%)
Physicians	289 (47.9%)	55 (19.0%)
P-value		0.045
Non-physicians	314 (52.1%)	41 (13.1%)
Healthy	414 (68.7%)	54 (13.0%)
P-value		0.004
Chronically ill	189 (31.3%)	42 (22.2%)
<44 years of age	298 (49.4%)	39 (13.1%)
P-value		0.06
≥44 years of age	305 (50.6%)	57 (18.7%)

This year, physicians were more interested in SIV that non-physicians, as seen from the statistically significantly higher proportion of physicians among all vaccinated HCWs (47.9%) compared to their proportion among HCWs to whom SIV was offered (23.9%, p < .001). As seen from the analysis of responses, 19% of physicians receiving SIV this year were vaccinated before the last influenza season, a statistically significantly higher proportion than that of non-physicians (13.1%, p = .045).

Chronically ill respondents were more willing to receive SIV in the past than their healthy counterparts. Out of 189 chronically ill HCWs, 101 (53.4%) were vaccinated at some time in the past and 42 (22.2%) before the last season. Out of the remaining 414 respondents needing no long-term treatment, 153 (37%) received SIV in the past and only 54 (13%) last year. It means that vaccination before the last season (p = .004) as well as at any time in the past (p < .001) was statistically significantly more frequently received by respondents with chronic conditions. The most frequent chronic conditions in the study were arterial hypertension (n = 70), bronchial asthma (n = 37), thyroid disorders (n = 21), diabetes mellitus (n = 14) and rheumatic diseases (n = 5). Other chronic conditions were rarely stated by the respondents.

Vaccination motivation

Motivation to get vaccinated, as ascertained through eight multiple-choice options, is seen from Table 1 showing differences in the frequency of selecting various options between respondent subgroups. In the entire sample, motivation to get vaccinated stemming from concerns about possibly contracting influenza and COVID-19 at the same time (Option 2) was most frequently selected. Together with less commonly selected concerns about contracting influenza alone (Option 1), these two options represent self-protection. The second most frequently selected motive was family protection (Option 6), followed by patient protection (Option 5). Females were statistically significantly more likely to select protection of self and family than males. Non-physicians, as compared to physicians, and chronically ill HCWs, as compared with their healthy counterparts, were more motivated to get vaccinated because of concerns related to influenza alone. Similarly, non-physicians and chronically ill participants were more concerned about possibly contracting influenza and COVID-19 at the same time, albeit without statistical significance. Concerns about contracting influenza alone was significantly more frequently the reason stated by HCWs vaccinated in the past and before the last season as compared with those receiving no previous vaccination. Concerns about contracting both influenza and COVID-19 were a significant motivator in previously unvaccinated individuals. Concerns about a shortage of vaccines in the facility giving previous vaccination were more frequently selected by HCWs vaccinated in the past and statistically significantly more often by those vaccinated last year. Younger respondents were statistically significantly more likely to state that they were trying not to spread influenza while doing their job (patient protection).

Discussion

In the sample of 603 currently vaccinated HCWs, only 15.9% were vaccinated before the last influenza season (2019/20), indicating a potential for improving the previously low coverage rates. The results demonstrate a significantly higher demand for SIV among physician compared to non-physician HCWs both in the last and current influenza seasons. Higher coverage rates achieved in physicians than in non-physicians during vaccination campaigns can be found in other available studies. A Turkish study of 572 HCWs from a children tertiary care hospital revealed, after a regression analysis, that being a nurse was associated with a lower vaccination rate (odds ratio 0.23 for vaccination among nurses) in the season 2017/18.¹³ In a large study (n = 4,138), Maffeo et al. noted a higher coverage rate among physicians (40.7%) compared to nurses (11.9%) during a 2019 vaccination campaign in an Italian tertiary care hospital.¹⁴ These findings are in line with those by von Linstow et al. from a Danish tertiary care pediatric facility (n = 555) showing coverage rates of 56.5% in physicians and 34.8% in nurses during the season 2018/19.¹⁵ Higher SIV coverage among physicians may be explained by their greater awareness of influenza-related risks and, on the other hand, more frequently perceived concerns about SIV side effects and ineffectiveness among non-physicians.^13–17 Consistent with the results of the present survey, it is clear that non-physician HCWs should be more targeted by SIV-promoting campaigns.

Considerable differences in SIV coverage between various countries mentioned in the Introduction section are confirmed by two aforementioned studies. The Italian study reported the overall coverage of 21.5% in HCWs, whereas the Danish study reported a rate of 38.6%.^14,15

A cross-sectional study by Wang et al. conducted among 806 Hong Kong nurses from various types of healthcare settings found that the refusal rate of SIV reduced during the COVID-19 pandemic.¹⁸ Unexpected situations with perceived threat were shown to change HCWs’ motivation to get vaccinated, potentially explaining the success of the presented vaccination measure in our hospital.^7,8

Several studies have focused on motivation for SIV among HCWs. A cross-sectional survey by Costantino et al. conducted in a sample of 2,356 Sicilian HWCs from tertiary care hospitals identified that the main motive for SIV was to protect patients during the 2019/20 influenza season. Moreover, higher self-perceived risk of contracting influenza was significantly associated with adherence to SIV during the last five seasons.¹⁹ Self-protection was the most common motive for influenza vaccination in a country-wide study among 27,163 German HCWs from 171 hospitals in the season 2018/19.²⁰ In their cross-sectional survey of HCWs (n = 363) from a tertiary care pediatric hospital in Greece, Kopsidas et al. also identified protection of self, family, patients and colleagues as the most common motivation in the influenza season 2016/17.²¹ Self-protection was the most frequent motive for SIV in the present survey as well (Table 1). Besides, self-protection was the vaccination motive most commonly associated with significant differences between subgroups; it was an option more frequently selected by non-physician, females and chronically ill HCWs. By contrast, the evidence from HCWs refusing SIV suggests that unvaccinated non-physicians are less concerned about influenza than unvaccinated physicians. Raising awareness about influenza itself and SIV safety and effectiveness plays a key role in increasing SIV coverage among HCWs.¹⁶ As for the revealed sex differences (Table 1), there are not many similar studies in the literature to compare with. However, the finding that females in the present survey more frequently selected the motive of self-protection is consistent with the ability of COVID-19 to arouse fear especially among women.²² Unsurprisingly, respondents vaccinated in the past were more concerned about contracting influenza alone than those with no previous SIV. On the other hand, HCWs vaccinated in the past, especially before the previous season, were less concerned about the coincidence of influenza and COVID-19.

Almost a third of the study sample reported the presence of chronic diseases, mostly arterial hypertension and bronchial asthma, which was also connected with a higher level of self-protection in terms of motivation for SIV (Table 1). However, not only chronically ill HCWs are more motivated to get vaccinated. In a national cross-sectional study of the Chinese general population aged 40 years or older (n = 74,484), Fan et al. showed a significantly higher vaccination rate in the season 2014/15 among people with chronic diseases, especially bronchial asthma and emphysema.²³

The efforts not to pass influenza to either family members or patients were also frequent motives for SIV in the present survey (Table 1). The fact that females were significantly more concerned about family protection than males may be explained by gender differences, with women being more family-oriented.²⁴ Younger HCWs were more frequently concerned about protecting patients from influenza than older respondents. Younger HCWs’ effort to avoid transmitting influenza to their patients may be influenced by age-dependent incidence of severe influenza affecting the elderly along with an age-dependent perception of SIV.²⁵ Overall, almost half of the respondents considered the opportunity to be vaccinated directly at their workplace as motivating, with the proportion being significantly higher among chronically ill than healthy HCWs. This is consistent with Hakim et al. stating that easy availability helped to reach a high coverage of SIV as well as Abu-Gharbieh et al. showing that unavailability was a reason for not taking SIV.^26,27 Interestingly, neither concerns about a lower income during a temporary sick leave nor the fact that the present vaccination was free of charge were strong motivators in the present survey.

Vaccination rates remain unacceptably low in some European healthcare institutions. The approach of authorities and various targeted initiatives play a crucial role in increasing the rates. The aforementioned study by Kopsidas et al. showed an increase in SIV uptake by HCWs from 19% to 31% between the seasons 2015/16 and 2016/17 following an initiative including education on influenza and SIV, together with communication of SIV availability and opportunity (time and place).²¹ Similarly, Boey et al. reported an improvement in SIV coverage among HCWs in 11 Belgian long-term care facilities from 54% in 2016 to 68% in 2017 that followed a vaccination campaign. The campaign included easy-access vaccination, role model involvement, personalized promotional materials, education and extensive communication.²⁸ Our promotion campaign comprised information about SIV benefits on the hospital internal network based on available scientific data, including those on the association with COVID-19. The presented findings such as the lower SIV adherence among non-physicians and differences in the motives can be used for developing future vaccination strategies. The exceptionally high response rate (>95%) may be explained by the fact that questionnaires were filled in during the post-vaccination observation period when respondents had to stay at the place of vaccination to be under medical supervision.

The study has its limitations as we do not know how many HCWs not vaccinated in the hospital received the vaccination elsewhere or had contraindications to it. We could only compare SIV coverage rates reported by the survey participants vaccinated this year. Since this was the first survey on the motivation for SIV in our hospital, we could not perform a direct head-to-head comparison between HCWs vaccinated before the 2020/21 and previous influenza seasons. However, including subjective information about vaccination at any time before the 2019/20 season allowed us to more effectively confirm both the association of certain motives, such as concerns about influenza alone or family protection, with SIV history and higher adherence to SIV among chronically ill participants.

In conclusion, COVID-19 contributes to an increased demand for SIV among HCWs. Compared to non-physicians, physicians showed a significantly higher demand for SIV in the previous (2019/20) and current (2020/21) influenza seasons. In the sample, the most frequent motive for SIV was self-protection, followed by family and patient protection. The findings can be used when developing new vaccination strategies aiming to increase vaccination coverage in the future.

Funding Statement

The study was supported by MH CZ – DRO (FNOL, 00098892) and the Palacký University Fund (RVO, 61989592).

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.