DOI: https://doi.org/10.21203/rs.3.rs-1710354/v1
Healthcare workers were the priority group for influenza vaccination, however, the vaccination rate among them in China had always been low. This study was conducted to investigate the influenza vaccination status among Chinese healthcare workers (HCWs) during the 2020/2021 and 2021/2022 influenza seasons and analyze the factors driving vaccination.
We provided Electronic questionnaires to the healthcare workers from January 27, 2022 to February 21, 2022 using the WeChat platform "Breath Circles". Binary logistic regression models were used to analyze the factors associated with vaccination among healthcare workers.
Among the 1697 healthcare workers surveyed, the vaccination coverage during the 2020/2021 and 2021/2022 influenza seasons was 43.67% (741/1697) and 35.36% (600/1697), respectively. Additionally, during the 2020/2021 and 2021/2022 influenza seasons, only 22.69% (385/1697) and 22.10% (358/1697) surveyed healthcare workers reported that their workplaces implemented the free vaccination policy for all employees, respectively.
Free influenza vaccination policy and workplace mandatory vaccination are effective in improving the influenza vaccination coverage in healthcare workers. The Chinese healthcare workers’ influenza vaccination coverage remained low and showed a downward trend after the outbreak of the COVID-19 pandemic. Further effective measures should be taken to improve influenza vaccination coverage.
Seasonal influenza is a serious respiratory infectious disease caused by the influenza virus. Annually, influenza contributes to 291,243–645,832 deaths from respiratory-related diseases throughout the world [1]. Nonetheless, existing studies focus on influenza-related respiratory mortality, which may underestimate the true burden of death caused by influenza [1].
Vaccination remains the most effective way to reduce the incidence and severity of influenza [2]. It reduces the chance of contracting influenza and alleviates influenza symptoms, significantly reducing the burden of disease and morbidity. However, strains mutate rapidly and the protective effect after vaccination lasts for approximately 6 months; therefore, annual influenza vaccination alone guarantees the preventive effect [3].
Due to occupational reasons, HCWs are at a higher risk of exposure to respiratory pathogens than the general population [4]. Infected HCWs may cause epidemics in the hospital by spreading the disease to patients and their families as well as to the HCWs’ family members. Unvaccinated HCWs had higher absenteeism than vaccinated HCWs; this has direct and indirect costs [5]. Besides, during the COVID-19 pandemic, unvaccinated HCWs may have been infected with COVID-19 as well as influenza, thus greater risk of affecting their health and bringing the reduction of medical staff.
Therefore, it is crucial for HCWs to be vaccinated against influenza. This study was conducted to determine the influenza vaccination coverage and factors driving vaccination among Chinese HCWs in the 2020/2021 and 2021/2022 influenza seasons, in order to provide reference for expanding the influenza vaccination coverage among HCWs.
From January 27, 2022 to February 21, 2022, an Internet-based cross-sectional study was conducted on the WeChat platform "Breath Circles", with 235,000 users covering 29 provincial regions across China. The user group mainly consisted of professionals working in respiratory medicine, infectious diseases, emergency departments, pediatrics, and other departments. The eligibility criteria required the users to mention their occupation and confirm their workplace as the hospital. According to our previous studies, a questionnaire consisting of three main aspects was designed:
(1) The basic details of the HCWs, including age, gender, and occupation.
(2) The workplace vaccination policies regarding influenza.
(3) HCWs’ knowledge about vaccination cognition and their willingness, reasons for hesitation, and suggestions for expanding vaccination coverage.
The questionnaire was distributed to the "Breath Circles" users in the form of questionnaire star(wjx.cn), a questionnaire design program.
We posted a link to the questionnaire on the "Breath Circles" forum, in order that HCWs who received the link could forward it to their colleagues; each participant could only answer once. For some questions, respondents could select multiple options. According to the National Influenza Prevention and Control Plan of the Chinese government, we divided the departments in two groups: "high-risk departments" included respiratory, infectious diseases, emergency, pediatrics, intensive care unit/intensive medicine, fever clinic, geriatrics, and obstetrics and gynecology departments; and "other departments" included the remaining departments.
We obtained demographic data from the National Health Commission of China to compare our study population with the general population of Chinese HCWs for 2021 [6]. The gross domestic product (GDP) per capita of the provinces is obtained by the National Bureau of Statistics [7].
Our definitions of vaccination policies and workplace regulations were as follows:
(1) Vaccination policies were divided into four types: The hospital offered free influenza vaccination to all employees in the hospital, free vaccination to high-risk department personnel, no free influenza vaccine to employees, and the respondent was not clear about hospital’s policy. Free vaccination policy means the cost of vaccines and vaccination services was borne by the workplace, including direct payment or reimbursement by the workplace after vaccination.
(2) There were four types of vaccination regulations in the workplace: required, encouraged, no intervention, and unknown. Required vaccinations: hospitals issue official documents or regulations requiring employees to be vaccinated; encouraged vaccinations: hospitals incentivize employees to receive the flu vaccine through health education or the dissemination of knowledge; no intervention: hospitals neither required nor encouraged employees to be vaccinated; unknown: respondents were unaware of any workplace regulations regarding influenza vaccines.
The survey results obtained using the questionnaire star were imported into MS Excel for data collation and cleaning, and analyzed with SPSS 23.0. All categorical variables were compared by using the chi-square test (α = 0.05). Binary logistics regression models were used to analyze the factors associated with vaccination among HCWs. The dependent variable was whether the HCW was vaccinated during the 2020/2021 and 2021/2022 influenza seasons. Demographics, workplace vaccination policies, vaccination cognition, and willingness were included in the regression models as independent variables.
The study protocol and questionnaire were approved by the Medical Ethics Committee of the Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China (CAMS&PUMC-IEC-2022-019). All participants had provided informed consent forms before logging in to fill out the questionnaire.
This survey collected 1697 valid questionnaires. Of the 1697 respondents, 187 (11%) worked in primary hospitals, 392 (23%) in secondary hospitals, 1118 (66%) in tertiary hospitals; 1095 (65%) in high-risk departments, 602 (35%) in other departments; 1023 clinicians (60%), 438 nurses (26%), vaccinators 21 (1%), medical technicians 104 (6%), and 111 (7%) in other categories. Table 1 summarizes the gender, age, length of service, education, and professional title of the surveyed HCWs and compares them with those of the population of HCWs in China.
The median age of HCWs surveyed was 37 years (range, 18–65 years) and the median duration of working was 12 years (range, < 1 to 45 years). Compared to the population of HCWs in China, HCWs in this study had a higher degree of education (Table 1).
| Characteristic | Category | HCWs in China (%) | HCWs in This Study (%) | p-Value for Chi-Square Test |
|---|---|---|---|---|
| Gender | 0.31 | |||
| Male | 27.6 | 34.5 | ||
| Female | 72.4 | 65.5 | ||
| Age in years | 0.15 | |||
| < 25 | 8.9 | 6.2 | ||
| 25–34 | 40.0 | 32.6 | ||
| 35–44 | 24.8 | 40.2 | ||
| 45–54 | 16.5 | 16.9 | ||
| 55–59 | 4.7 | 3.1 | ||
| ≥ 60 | 5.1 | 1.0 | ||
| Years of working | 0.21 | |||
| < 5 | 24.9 | 17.7 | ||
| 5–9 | 23.1 | 19.2 | ||
| 10–19 | 23.1 | 36.4 | ||
| 20–29 | 16.2 | 18.8 | ||
| ≥ 30 | 12.7 | 8.0 | ||
| Education degree | < 0.0001 | |||
| Postgraduate | 5.9 | 23.6 | ||
| Bachelor & Junior college | 74.6 | 74.7 | ||
| ≤Technical secondary school | 19.4 | 1.7 |
Among the 1697 respondents, vaccination coverage was 43.67% (741/1697) and 35.36% (600/1697) in the 2020/2021 and 2021/2022 influenza seasons, respectively. Out of the vaccinated HCWs in the 2021/2022 influenza season, 48.33% (290/600) received instant free vaccination, 14.83% (89/600) were reimbursed by hospitals after vaccination, 30.17% (181/600) were vaccinated at their own expense, 6.00% (36/600) received Medicare reimbursement, and 0.67% (4/600) werepaid by other means.
Analysis of HCWs influenza vaccination coverage during the 2020/2021 and 2021/2022 influenza seasons: The vaccination coverage of HCWs living in medium per capita GDP provinces was higher than those living in lower per capita GDP provinces (2020/2021, p < 0.05). Additionally, the vaccination coverage of HCWs living in medium and high per capita GDP provinces were higher than those in low per capita GDP provinces (2021/2022, p < 0.05). The vaccination coverage of HCWs who were engaged in vaccination drives was higher than those were not (2020/2021, 2021/2022, p < 0.05). Hospitals that set up routine vaccination clinics had higher vaccination coverage than those who did not (2020/2021, p < 0.05)(Table 2). Regarding policy: HCWs who were required to be vaccinated as per hospital regulations were more likely to be vaccinated (2020/2021, 2021/2022, p < 0.05). HCWs whose hospital implemented the free influenza vaccine policy for all the staff were more likely to be vaccinated (2020/2021, 2021/2022, p < 0.05) (Table 3). On the knowledge about vaccination and willingness aspect: HCWs who actively learned about vaccines and were knowledgeable were more likely to be vaccinated than those who did not actively learn (2020/2021, p < 0.05). HCWs who supported vaccination for all HCWs were more likely to be vaccinated (2020/2021, 2021/2022, p < 0.05). If the vaccination was provided free of cost, HCWs were more likely to be vaccinated (2020/2021, 2021/2022, p < 0.05) (Table 4).
| Characteristic | Number of people surveyed | The number of people vaccinated | Univariate Analysis (2020/2021) | Multivariate logistic regression (2020/2021) | Univariate Analysis (2021/2022) | Multivariate logistic regression (2021/2022) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (2020/2021) | (2021/2022) | X2 | P | Exp (B) | 95% CI | P | X2 | P | Exp (B) | 95% CI | P | ||
| Age | 16.66 | < 0.05 | 11.59 | < 0.05 | |||||||||
| < 25 | 105 | 45(42.86%) | 42(40.00%) | < 0.05 | |||||||||
| 25–34 | 553 | 206(37.25%) | 167(30.20%) | 1.14 | (0.65,1.98) | 0.65 | |||||||
| 35–44 | 683 | 311(45.53%) | 248(36.31%) | 1.82 | (1.03,3.22) | 0.04 | |||||||
| 45–54 | 287 | 145(50.52%) | 117(40.77%) | 2.22 | (1.20,4.08) | 0.01 | |||||||
| 55–59 | 52 | 26(50.00%) | 20(38.46%) | 1.88 | (0.77,4.57) | 0.16 | |||||||
| ≥ 60 | 17 | 8(47.06%) | 6(35.29%) | 2.43 | (0.66,8.93) | 0.18 | |||||||
| Degree | 0.74 | 0.69 | 0.90 | 0.64 | |||||||||
| ≤Technical secondary school | 30 | 15(50.00%) | 13(43.33%) | ||||||||||
| Bachelor & Junior college student | 1267 | 556(43.88%) | 448(35.36%) | ||||||||||
| Postgraduate | 400 | 170(42.50%) | 139(34.75%) | ||||||||||
| Province by GDP per capita a | 20.79 | < 0.0001 | 31.60 | < 0.0001 | |||||||||
| Low GDP | 1146 | 468(40.84%) | 369(32.20%) | 0.02 | < 0.05 | ||||||||
| Mid GDP | 318 | 140(44.03%) | 111(34.91%) | 1.55 | (1.11,2.17) | 0.01 | 1.63 | (1.15,2.29) | < 0.05 | ||||
| High GDP | 233 | 133(57.08%) | 120(51.50%) | 1.40 | (0.94,2.10) | 0.10 | 1.65 | (1.11,2.45) | 0.01 | ||||
| Occupation | 22.73 | < 0.0001 | 23.02 | < 0.0001 | |||||||||
| Clinicians | 1023 | 428(41.84%) | 335(32.75%) | 0.01 | 0.02 | ||||||||
| Nurses | 438 | 202(46.12%) | 175(39.95%) | 1.06 | (0.78,1.44) | 0.73 | 1.16 | (0.85,1.58) | 0.35 | ||||
| Medical technicianb | 104 | 56(53.85%) | 48(46.15%) | 1.45 | (0.85,2.47) | 0.17 | 1.43 | (0.83,2.49) | 0.20 | ||||
| Vaccination staff | 21 | 17(80.95%) | 13(61.90%) | 6.55 | (1.96,21.85) | < 0.05 | 4.53 | (1.54,13.33) | 0.01 | ||||
| Others | 111 | 38(34.23%) | 29(26.13%) | 0.72 | (0.41,1.26) | 0.25 | 0.70 | (0.39,1.25) | 0.23 | ||||
| Years of Working | 12.58 | < 0.05 | 8.05 | 0.09 | |||||||||
| ≤ 5 | 300 | 115(38.33%) | 101(33.67%) | ||||||||||
| 5–9 | 325 | 126(38.77%) | 99(30.46%) | ||||||||||
| 10–19 | 618 | 277(44.82%) | 219(35.44%) | ||||||||||
| 20–29 | 319 | 155(48.59%) | 125(39.18%) | ||||||||||
| ≥ 30 | 135 | 68(50.37%) | 56(41.48%) | ||||||||||
| Professional title | 8.95 | < 0.05 | 4.84 | 0.18 | |||||||||
| Above Intermediate | 450 | 186(41.33%) | 155(34.44%) | ||||||||||
| Intermediate | 612 | 270(44.12%) | 218(35.62%) | ||||||||||
| Below intermediate | 536 | 253(47.20%) | 201(37.50%) | ||||||||||
| Unclassified / Unknown | 99 | 32(32.32%) | 26(26.26%) | ||||||||||
| Whether the Hospital has set up a routine vaccination clinic | 35.60 | < 0.0001 | 26.63 | < 0.0001 | |||||||||
| Yes | 1279 | 611(47.77%) | 496(38.78%) | ||||||||||
| No | 418 | 130(31.10%) | 104(24.88%) | 0.65 | (0.48,0.89) | 0.01 | |||||||
| Whether daily work involve in vaccination work | 28.54 | < 0.0001 | 39.30 | < 0.0001 | |||||||||
| Yes | 637 | 331(51.96%) | 285(44.74%) | ||||||||||
| No | 1060 | 410(38.68%) | 315(29.72%) | 0.71 | (0.55,0.93) | 0.01 | |||||||
| a: In terms of GDP per capita, provinces are divided into three levels: low, middle and high. Low for Anhui, Qinghai, Jiangxi, Shanxi, Tibet, Heilongjiang, Guangxi, Guizhou, Yunnan, Gansu; Middle for: Chongqing, Shaanxi, Liaoning, Jilin, Ningxia, Hunan, Hainan, Henan, Xinjiang, Sichuan, Hebei; High for: Beijing, Shanghai, Tianjin, Jiangsu, Zhejiang, Fujian, Guangdong, Shandong, Inner Mongolia, Hubei. | |||||||||||||
| b: Medical technicians include inspection, imaging, ultrasound, electrocardiogram, pharmacy, etc. Others include administration, logistics personnel, medical school staff, scientific research institute staff, medical students, etc. | |||||||||||||
| c: Primary hospitals: mainly refer to rural township hospitals and community health service centers that provide prevention, treatment, healthcare and rehabilitation services directly to communities of a certain population in China. Secondary hospitals: mainly refer to county-level hospitals that provide comprehensive medical and health-care services to multiple communities and undertake certain teaching and scientific research tasks. Tertiary hospitals: hospitals above the regional level that provides high-level specialized medical and health-care services and carries out higher education and scientific research tasks to multiple regions. | |||||||||||||
| Characteristic | Number of people surveyed | The number of people vaccinated | Univariate Analysis (2020/2021) | Multivariate logistic regression (2020/2021) | Univariate Analysis (2021/2022) | Multivariate logistic regression (2021/2022) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (2020/2021) | (2021/2022) | X2 | P | Exp (B) | 95% CI | P | X2 | P | Exp (B) | 95% CI | P | ||
| Workplace’s Policy | 293.82 | < 0.0001 | 306.71 | < 0.0001 | |||||||||
| Requirementa | 188 | 139(73.94%) | 124(65.96%) | < 0.0001 | < 0.0001 | ||||||||
| Promotion | 955 | 515(53.93%) | 433(45.34%) | 0.63 | (0.41,0.95) | 0.03 | 0.72 | (0.48,1.06) | 0.1 | ||||
| None | 428 | 80(18.69%) | 42(9.81%) | 0.32 | (0.19,0.54) | < 0.0001 | 0.28 | (0.17,0.49) | < 0.0001 | ||||
| Not clear | 126 | 7(5.56%) | 1(0.79%) | 0.09 | (0.04,0.23) | < 0.0001 | 0.03 | (0.00,0.19) | < 0.0001 | ||||
| Free vaccination | 414.41 | < 0.0001 | 482.08 | < 0.0001 | |||||||||
| For all staff | 518 | 385(74.32%) | 358(69.11%) | < 0.0001 | < 0.0001 | ||||||||
| For high-risk department | 258 | 158(61.24%) | 124(48.06%) | 0.56 | (0.38,0.80) | < 0.05 | 0.43 | (0.31,0.62) | < 0.0001 | ||||
| Have not free vaccination policy | 740 | 161(21.76%) | 100(13.51%) | 0.13 | (0.09,0.19) | < 0.0001 | 0.11 | (0.08,0.16) | < 0.0001 | ||||
| Not clear | 181 | 37(20.44%) | 18(9.94%) | 0.22 | (0.13,0.35) | < 0.0001 | 0.12 | (0.07,0.21) | < 0.0001 | ||||
| a: Requirement means hospitals issued official document or regulation to ask employees to get compulsory vaccination, but HCWs who have not received influenza vaccination will not be punished. | |||||||||||||
| Characteristic | Number of people surveyed | The number of people vaccinated | Univariate Analysis (2020/2021) | Multivariate logistic regression (2020/2021) | Univariate Analysis (2021/2022) | Multivariate logistic regression (2021/2022) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (2020/2021) | (2021/2022) | X2 | P | Exp (B) | 95% CI | P | X2 | P | Exp (B) | 95% CI | P | ||
| Whether taken the initiative to learn about vaccines and health related knowledge | 24.76 | < 0.0001 | 28.18 | < 0.0001 | |||||||||
| Yes | 1421 | 658(46.31%) | 541(38.07%) | ||||||||||
| No | 276 | 83(30.07%) | 59(21.38%) | 0.42 | (0.21,0.84) | 0.01 | |||||||
| Frequency of learning vaccines and health-related knowledge | 75.58 | < 0.0001 | 73.92 | < 0.0001 | |||||||||
| Once a day | 84 | 65(77.38%) | 54(64.29%) | 0.01 | |||||||||
| Once a week | 398 | 207(52.01%) | 177(44.47%) | 0.37 | (0.2,0.70) | < 0.05 | |||||||
| Once a month | 526 | 226(42.97%) | 184(34.98%) | 0.32 | (0.17,0.60) | < 0.0001 | |||||||
| Once half of a year | 285 | 114(40.00%) | 91(31.93%) | 0.38 | (0.19,0.73) | < 0.05 | |||||||
| Once a year | 128 | 46(35.94%) | 35(27.34%) | 0.42 | (0.19,0.89) | 0.02 | |||||||
| None | 276 | 83(30.07%) | 59(21.38%) | 0.01 | . | . | . | ||||||
| Frequency of recommending respiratory infectious diseases’ vaccine to suitable populations | 108.98 | < 0.0001 | 87.96 | < 0.0001 | |||||||||
| Frequently | 899 | 491(54.62%) | 402(44.72%) | < 0.0001 | < 0.0001 | ||||||||
| Occasionally | 685 | 234(34.16%) | 188(27.45%) | 0.51 | (0.39,0.67) | < 0.0001 | 0.54 | (0.41,0.71) | < 0.0001 | ||||
| Never | 113 | 16(14.16%) | 10(8.85%) | 0.24 | (0.12,0.48) | < 0.0001 | 0.20 | (0.09,0.43) | < 0.0001 | ||||
| Whether support all HCWs to uptake influenza vaccine | 86.94 | < 0.0001 | 68.71 | < 0.0001 | |||||||||
| Yes | 1510 | 719(47.62%) | 585(38.74%) | ||||||||||
| No | 187 | 22(11.76%) | 15(8.02%) | 0.27 | (0.16,0.46) | < 0.0001 | 0.31 | (0.16,0.57) | < 0.0001 | ||||
| Whether uptake influenza vaccine if the vaccination is free | 94.15 | < 0.0001 | 89.00 | < 0.0001 | |||||||||
| Yes | 1479 | 712(48.14%) | 585(39.55%) | < 0.0001 | < 0.0001 | ||||||||
| No | 77 | 8(10.39%) | 7(9.09%) | 0.28 | (0.12,0.64) | < 0.05 | 0.37 | (0.15,0.91) | 0.03 | ||||
| Not clear | 141 | 21(14.89%) | 8(5.67%) | 0.42 | (0.24,0.75) | < 0.05 | 0.18 | (0.08,0.40) | < 0.0001 | ||||
Of the 600 HCWs who were vaccinated during the 2021/2022 influenza season, 69.50% of them were vaccinated out of concern for infecting others, 66.50% were worried about contracting the flu themselves, and 41.33% were concerned about the impact of influenza on their work (Table 5).
| Reasons for vaccination a. | N(600) | Proportion |
|---|---|---|
| Being worried that influenza spread to others | 417 | 69.50% |
| Being worried about getting influenza | 399 | 66.50% |
| Preventing/reducing absenteeism from work | 248 | 41.33% |
| Required by the workplace | 217 | 36.17% |
| Easy access to vaccination from workplace | 198 | 33.00% |
| Recommendations from the national policy-making body (e. g. technical guidelines) | 142 | 23.67% |
| Free vaccination | 87 | 14.50% |
| Previous experience with vaccination | 16 | 2.67% |
| a༎ These reasons are not mutually exclusive. | ||
The WHO uses the “3 Cs” model to classify vaccine hesitancy: confidence, complacency and convenience [8]. Vaccination confidence is defined as trust in
the effectiveness and safety of vaccines
the system that delivers them
the motivations of policy-makers who decide on the needed vaccines.
Vaccination complacency exists where the perceived risks of vaccine-preventable diseases are low and vaccination is not deemed as a necessary preventive action. Complacency is influenced by many factors, including other life/health responsibilities that may be seen as more important at that point. Vaccination convenience is a significant factor when physical availability, affordability and willingness-to-pay, geographical accessibility, ability to understand (language and health literacy), and appeal of immunization services affect uptake.
Of the 1,097 HCWs who were not vaccinated during the 2021/2022 influenza season, HCWs reported that the main reason for not getting vaccinated was they were too busy at work (72.56%). Other reasons included the consideration that influenza infection was not serious (42.30%), reluctance to pay for vaccination (41.66%), inconvenient location for vaccination (28.99%), and fear of adverse reactions (27.53%). (Fig. 1).
HCWs reported that the factor most likely to promote influenza vaccination was the provision for free vaccination (82.09%). Other factors included setting up vaccination clinics or temporary vaccination points in the workplace (75.66%), encouraging vaccination at the workplace (61.58%), vaccination campaigns (58.46%), and requiring vaccination at the workplace (47.32%). The proportion of people who believed that none of the above measures would promote vaccination was only 4.77%.
For increasing the coverage of public influenza vaccination, 93.46% HCWs suggested incorporating influenza vaccination into the national immunization program; 81.32%, reducing self-payment; 78.20%, strengthening health education and publicizing knowledge about vaccination; 66.53%, optimizing the immunization service system; 61.99%, increasing vaccine production capacity; 56.51%, improving the treatment of public health practitioners; and 56.28%, increasing investment in public health personnel training (Fig. 2).
HCWs were the priority group for influenza vaccination in China and abroad; however, the domestic influenza vaccination rate had always been low. The respondents of this study were users from the "Breath Circles" platform, most of them respiratory physicians or nurses knowledgeable about the dangers of respiratory diseases. However, the vaccination rate among them in the 2021/2022 influenza seasons was 35.36%, far lower than that of developed countries in Europe and the United States [9]. This may be related to national policies: China had not included influenza vaccination in the immunization program. Only 19.0% respondents reported that their workplace offered free vaccination. Besides, except for mandatory vaccination, no single intervention has been shown to rapidly and substantially increase and sustain an uptake in vaccination [10]. A study found that voluntary policy-based vaccination rarely achieved and maintained > 40% influenza vaccination rate in practice [11]. In the United States, a large proportion of hospitals mandate HCWs to receive the influenza vaccine (61.4% in 2017) [12]. The Virginia Mason Medical Center in Seattle, USA, used influenza vaccination as an employment condition, and in 2005, the implementation of mandatory vaccination policies increased vaccination coverage for more than 5,000 HCWs in the next four influenza seasons by > 98% [13].
At the same time, the vaccination rate among HCWs during 2020/2021 and 2021/2022 influenza seasons in this study was higher than the 11.6% vaccination rate during the 2018/2019 influenza season [14], but lower than the 67% vaccination rate in the 2019/2020 influenza season [15]. The reason for the higher rate as compared to that of the 2018/2019 influenza season may be due to the official document issued by the Chinese Health Commission in 2018/2019 to encourage influenza vaccination. This was the first time specific requirements for the vaccination of HCWs were put forward, thus requiring medical institutions at all levels to provide free influenza vaccination services for HCWs and ensuring all HCWs in high-risk departments are vaccinated. The reason for the lower rate as compared to that of the 2019/2020 influenza season probably because the COVID-19 pandemic left HCWs busier with decreased access to the influenza vaccine. COVID-19 vaccination was the priority of all level medical facilities, and the influenza vaccine cannot be administered at the same time.
In addition, our research reported on the economic level of the city, engaged in vaccination work, frequent recommendation of respiratory infectious disease-related vaccines to suitable vaccination populations, supporting attitude for all HCWs be influenza vaccinated, work place requirement, work place free vaccination policies. HCWs were more likely to be vaccinated if vaccinations were free. Meanwhile, in this study, the top two reasons why HCWs were vaccinated during 2021/2022 were concerns about infecting others and contracting influenza themselves, which was consistent with those of previous studies in Europe (Italy [16], Belgium [17], Slovenia [18]), the Americas (Peru [19]), Australia [20], and Asia (Singapore [21], Hong Kong [22]).
Vaccine hesitancy among HCWs is also a public health challenge [23]. The main reasons why the HCWs in this study were not vaccinated during the 2021/2022 influenza season included inconvenient vaccination locations, which may be caused by the decreasing number of free influenza vaccination facilities under the impact of the COVID-19 pandemic, since more vaccination facilities were allotted for COVID-19 vaccination and the accessibility of the influenza vaccine worsened.
However, the COVID-19 pandemic has not subsided, and low influenza vaccination rates among HCWs may cause problems. The high incidence of influenza may cause HCWs to suffer from both influenza and COVID-19, or other respiratory infectious diseases, resulting in an epidemic of multiple respiratory infectious diseases, which may infect colleagues and patients. Besides, the influenza vaccine also strengthens immunity and reduces the severity of COVID-19 [24]. The WHO noted in the Global Influenza Strategy 2019–2030 that an outbreak of influenza may highlight the burden and severity of annual epidemics on the global population and health systems of countries; seasonal epidemics may highlight the economic burden of direct and indirect costs [25]. A recent study in the United States showed that mandatory influenza vaccination policies reduced symptom absenteeism rates among HCWs as influenza vaccination rates increased [26]. Influenza vaccination also saved countries costs: a review of more than 140 studies showed that the per capita cost of incidences of seasonal influenza ranged from US$ 30 to over US$ 60, and that cost–effectiveness ratios for vaccination ranged from US$ 10,000/outcome to more than US$ 50,000/outcome [27]. Thus, it can be seen that influenza vaccination is cost-effective.
In summary, further effective measures should be taken to improve influenza vaccination coverage among HCWs. Our research found that HCWs who were required to be vaccinated by hospitals were more likely to be vaccinated; this is consistent with findings in the United States where influenza HCW vaccination rates were 92.3% in hospitals during 2016–2017 [28], and the highest vaccination rates were recorded in HCWs whose employer required influenza vaccination (96.7%) as compared to 45.8% in healthcare facilities where influenza vaccination was not required, promoted, or offered on-site. As free vaccination was most likely the driving factor in promoting influenza vaccination among HCWs, hospitals could formulate free vaccination policies to encourage vaccination. In addition, the convenience of influenza vaccination also needs to be improved through measures such as improving the public health function of hospitals and providing influenza vaccination points in hospitals. The technical guidelines for influenza vaccination in China (2021–2022) also recommend increasing the number of primary influenza vaccination points, starting vaccination earlier, extending the duration of vaccination, increasing daily service hours, and encouraging influenza vaccination campaigns for HCWs [29]. In addition, since influenza and COVID-19 vaccines cannot be administered at the same time, the current Technical Guidelines for COVID-19 Vaccination (First Edition) in China recommend that the interval between influenza and COVID-19 vaccinations should be > 14 d. However, existing research has not found clear evidence of immunogenicity and safety concerning inactivated influenza vaccines and combining immunization [30]. Future studies could focus on combining immunization regimens, which is important for the prevention and control of the risk of superimposed epidemics in the future.
There are several limitations in this study. The HCWs in this study had a higher degree of education than HCWs in China in general. Therefore, our findings may not represent the vaccination status of HCWs nationwide. However, low vaccination rates among these highly educated HCWs also reflect the poor rates of vaccination among the general population in China. Second, the vaccination status of HCWs in this study was self-reported rather than based on their actual vaccination records, which may cause recollection bias. In the future, we will continue to track surveyed HCWs, expand the survey population, and focus on the changes in influenza vaccination order to provide reference for vaccination and influenza prevention and control.
The HCWs’ influenza vaccination coverage in China remained low and showed a downward trend during COVID-19 pandemic. Free influenza vaccination policy and workplace mandatory vaccination are factors driving vaccination. Improving influenza vaccination coverage among HCWs needs further effective measures and the public health function of hospitals should be improved: hospitals could formulate free vaccination policies and improve the convenience of influenza vaccination through measures such as providing influenza vaccination points in hospitals. Besides, combining immunization regimens could be considered in future studies.
healthcare workers.
Ethics approval and consent to participate: The study protocol and questionnaire were approved by the Medical Ethics Committee of the Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China (CAMS&PUMC-IEC-2022-019). All participants had provided informed consent forms before logging in to fill out the questionnaire.
Consent for publication: We can submit consent form when needed.
Availability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.
Competing interests: The authors declare that they have no competing interests.
Funding: This research was funded by Peking Union Medical College Group Medical Discipline Construction Project, NO: WH10022021145; Guilin talent mini-highland scientific research project, (Municipal Committee Talent Office of Guilin City [2020] No. 3-05); the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences, NO: 2021-RC330-002.
Authors' contributions: Libing Ma: Conceptualization; Methodology; Writing - Review & Editing; Supervision; Project administration. Xuan Han: Formal analysis; Data Curation; Writing - Original Draft. Yuan Ma: Visualization. Yuan Yang: Investigation. Yunshao Xu: Data Curation. Di Liu: Software, Resources. Weizhong Yang: Supervision; Writing - Review & Editing; Investigation. Luzhao Feng: Supervision; Writing - Review & Editing; Project administration
Acknowledgements: We acknowledge support by the “Breath Circles” WeChat platform.
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