1. Introduction
In November of 2019, the first cases of pneumonia of an unknown etiology were diagnosed in China [
1]. The rapid increase in the number of human infections and deaths in Wuhan, in the central Hubei province of the country, resulted in an intensive search for the etiological factor and led to the identification of a new coronavirus, initially named 2019-nCoV [
2]. This was the second identified severe acute respiratory syndrome (SARS) coronavirus, designated by the WHO as a variant of concern (VoC), and thus giving rise to the name of the new virus—the world-famous SARS-CoV-2 [
3,
4]. The virus is transmitted by airborne droplets, which causes acute respiratory infection coronavirus disease 2019 (COVID-19) [
4,
5]. In some patients, it causes severe pneumonia and acute respiratory distress syndrome, requiring mechanical ventilation. Moreover, an infection can result in further complications such as endothelial disease, wreaking indiscriminate havoc on multiple organs including the lungs, heart, brain, kidney, and vasculature [
6,
7].
At the time of writing, it has only been nine months since the World Health Organization announced (11 March 2020) the pandemic of SARS-CoV2, and the first vaccination against COVID-19 was administered in December 2020 [
4,
8,
9,
10]. At the present moment, vaccinations seem to be the only tool that can effectively and safely reduce the spread of the virus, with all its consequences and costs.
The vaccination program in Poland started on 27 December 2020 [
11]. Until then, 1,257,799 COVID-19 cases had been reported in Poland, and 27,118 people had died. According to reports from the Ministry of Health during this period, 20,476 doctors, 50,990 nurses, and 4764 midwives had become infected, of which 66, 51, and 4 died, respectively [
12]. For the first time in Poland, a national comprehensive, completely voluntary, but free vaccination program covering the whole population was introduced [
11]. In this National Program, the whole population was divided into four groups according to the high level of exposure to infection and the severity course of the SARS-CoV-2 infection (including the highest risk of death). The first group, called group zero, included healthcare professionals (including medical students) who are particularly vulnerable to SARS-CoV-2 infection, and whose work is strategically important to the whole of society. The other groups were residents of nursing homes, people over 60 years of age, employees of uniformed services and teachers (group one); people under 60 years of age with chronic diseases (group two); and other adult populations (group three).
With the approval of the European Medicines Committee (EMA) and the European Commission, Poland received the SARS-CoV-2 vaccines. The Polish government first purchased the two-dose vaccines BNT162b2 mRNA COVID-19 by BioNTech/Pfizer [
13], ChAdOX1nCoV-19 by AstraZeneca [
14], and mRNA-1273 SARS-CoV2 vaccine by Moderna [
15], followed by the single-dose Ad26.COV2.S COVID-19 vaccine by Johnson & Johnson [
16]. Both BioNTech/Pfizer and Moderna vaccines contain the so-called template ribonucleic acid (mRNA) encoding the SARS-CoV-2 coronavirus coat protein. The mRNA is located in the lipid coat, enters the cell, and triggers the production of a protein in the ribosomes, which is responsible for triggering an immune system response in the vaccinated person. Meanwhile, vector vaccines such as AstraZeneca and Jonhson & Jonhson are based on the adenovirus, which triggers an immune response by transferring fragments of genetic material to human cells and serving as an information carrier for the production of SARS-CoV-2 proteins. These types of vectors had also been used in vaccines against Ebola, HIV, RSV, and Zika virus vaccines [
17].
The first vaccine available in Poland was BioNTech/Pfizer, followed by Moderna and AstraZeneca. The Johnson & Johnson vaccine was used only from the second half of April 2021 [
11]. However, especially at the beginning, the vaccines were delivered with a delay, in a smaller number of units than originally purchased, and supplies were frequently suspended by the producer—which all made it impossible to carry out the planned vaccinations smoothly. Individuals in group zero, including healthcare workers (HCWs), did not have a choice in the kind of vaccine they received. HCWs were initially vaccinated only with the BioNTech/Pfizer vaccine. In the second half of January, Moderna vaccines began to arrive in Poland, but in such small quantities that the probability of being vaccinated with this vaccine was very low. At the end of January, AstraZeneca vaccines were also delivered to Poland. Due to the shortage in the supply of the vaccines by BioNTech/Pfizer and Moderna, the AstraZeneca vaccines temporarily became the only available vaccine, with the BioNTech/Pfizer and Moderna vaccines only available as a second dose for those previously vaccinated. A choice of a vaccine was only possible from the turn of April and May [
11].
By 15 May 2021, approximately 15.5 million vaccines against SARS-CoV-2 had been used in Poland, and about 4.4 million people were fully vaccinated [
11]. At the same time, in connection with vaccination with any of the four vaccines used in Poland, 6051 adverse post-vaccination reactions were reported to the State Sanitary Inspection, of which 5161 were mild [
18]. The official definition of adverse post-vaccine reactions (APVR) is a disorder health condition (often transient and mild), which occurs within four weeks after administration of the vaccine (the exception is the administration of the tuberculosis vaccine, where the time criterion is longer than four weeks) [
19]. In Poland, according to Art. 21 of the Act on preventing and combating infections and infectious diseases in humans, the post-vaccination adverse reaction should be reported to Sanitary Inspection [
18,
20].
Cases of post-vaccination reactions in thousands of vaccinated people, along with the relatively short time in which the vaccines were created and obtained, have become a pretext for anti-vaccination movements to undermine the safety and effectiveness of COVID-19 vaccines, and a cause for inducing pre-vaccination fear in society.
Following this important epidemiological and social topic, the present study aims to assess vaccination coverage in Poland against COVID-19 among healthcare workers, nurses, doctors, midwives, and students at a medical university (nursing, midwifery, medicine). Since the availability of vaccinations, there have been numerous studies evaluating the intention to get vaccinated against SARS-CoV-2 among health professionals in different European and non-European countries; however, the results showed wide variability [
21,
22,
23,
24]. The present research is one of the few studies so far that shows the actual rate of vaccination at a time when full vaccination was possible for all HCWs who wanted to take the vaccine. Our objective was also to explore the motivations of health professionals for getting vaccinated, and their vaccine-related stress. This research estimated the frequency and intensification of adverse post-vaccination reactions associated with vaccination with BioNTech/Pfizer and AstraZeneca. In addition, this study aimed to determine the ratio of HCWs to vaccines against COVID-19 after vaccination, and their motivation to continue vaccination in the future, which may potentially translate into the attitude towards this vaccination across the whole of society.
4. Discussion
In the present study, many of the important issues around vaccination against COVID-19 were investigated. Based on the available publications and the best knowledge of the authors, this is the first study that presents the vaccination coverage level against COVID-19 among different groups of healthcare workers and two majors of medical students six months after the introduction of vaccinations in Poland. The immunization coverage was 94.8% among doctors, 78.9% in nurses and midwives, 98.3% in medical students, and 86.3% in nursing and midwifery students.
Our study confirms the findings of a pre-vaccination survey carried out in Slovenia, which showed that a higher percentage of physicians and medical students intended to get vaccinated when compared to nurses [
28]. Additionally, in Turkey, the risk of not getting vaccinated/late vaccination was significantly higher in nurses/midwives than in doctors [
29], while among French HCWs, the highest percentages of those wanting to become vaccinated were physiotherapists (95.8%) and doctors (92.1%), followed by pharmacists (88.8%), and the lowest were nurses (64.7%) [
21]. Moreover, a survey conducted by the American Nurses Foundation published in October 2020 suggested that only 34% of nurses were willing to be vaccinated with the COVID-19 vaccine, while 36% refused and 31% were unsure [
30].
On the other hand, the level of immunization among nurses in Poland, although slightly lower than that obtained in doctors and medical students, was still very high. This figure was higher than the threshold for a population to gain herd immunity. This is a significantly better result compared to the annual vaccination coverage of influenza among HCWs in Poland (5–10% for nurses and about 20% for doctors) [
31]. Moreover, the vaccination rate in our study population was much higher than the COVID-19 vaccine acceptance rate in the Polish general public among adults (56.9%) [
32]. Additionally, more surveyed medical students in Poland (92%) than non-medical students (59.4%) indicated a desire to get vaccinated against SARS-CoV-2 [
33]. Similar to our study, HCWs in Qatar showed a higher rate of vaccine acceptance when compared to other non-health-related disciplines [
22].
Moreover, the vaccination rate of HCWs in Poland was found to be significantly higher than that predicted before the vaccine became available. For example, the declaration rate ranged from 27.7% for HCWs in The Democratic Republic of the Congo (March and April 2020) [
34]; 44.2% for health science and medicine students [
35], 52.0% for HCWs [
23], and 61.8% for GPs in Malta (September 2020) [
36]; 61,1% for nurses and 78.1% for doctors in Israel (March and April 2000) [
24]; 63% for nurses in Hong Kong (March to April 2020) [
37]; 76.9% for HCWs in France (March to July 2020) [
21]; to 86.1% for university students in Italy (June 2020) [
38]. A study of the intentions of Polish HCWs to be vaccinated was completed in autumn of 2020 and showed that less than 70% of respondents would like to be vaccinated against COVID-19 [
39]. Likewise, higher actual vaccination coverage among health professionals could therefore be expected in other countries, due to the higher immunization coverage in the general population than the earlier forecasts for HCWs [
21,
23,
36,
37,
38,
40]. On the other hand, only a slight increase in the willingness to get vaccinated against COVID-19 was reported in the general population in Poland 2 months after the start of the vaccination program compared to the period before the commencement of the vaccination program; in both cases about 50% [
41]. This level of vaccination coverage in Poland was achieved in August 2021, 4 months from the time when vaccination became available to all citizens [
42]. Since then, the increase in vaccination coverage has been slow, and vaccinations in the last 3 months have mostly been taken by those who decided to take the 3rd dose, not those who had not been vaccinated so far (except for the age group 5–11, which was only approved for vaccination at the end of December 2021) [
40,
42].
Several factors may have an influence on HCW attitudes toward COVID-19 vaccination in Poland. The most important being easy access to vaccines and no payment for them. The vaccination procedure for HCWs and medical students in Poland was organized by hospitals, clinics, and universities. It was sufficient to express a willingness to be vaccinated by e-mail or by phone, and you would be informed about the time and place of vaccination afterwards. Additionally, although vaccination against COVID-19 is voluntary for the time being, university authorities and directors of health centers have introduced educational programs, invoked responsibility for patients, and applied some pressure to achieve the highest possible level of vaccination among HCWs. Additionally, a group of students in our study mentioned that one of the reasons for undergoing vaccination was due to concerns about the possibility of participating in clinical classes, internships, or attempts to graduate from medical studies in the event of not being vaccinated. In addition, around 30% of primary healthcare workers in the study postulated that vaccination against COVID-19 should be mandatory among healthcare professionals, but only if vaccination is free. This is particularly important in the context of the announcement of obligatory vaccination against COVID-19 of HCWs in Poland in the near future (March 2022). Some European countries such as France, Greece, Italy, and Hungary already made COVID vaccination mandatory for healthcare workers last year [
43,
44]. Implementing this policy is a response to a social need for the protection of public health, and above all as a defense for patients, for whom HCWs have a specific position of guaranteed protection and trust. Simultaneously, to obtain a sufficient level of immunization in the general population, some countries have chosen to adopt a control measure called "vaccine passports" [
45]. The pass is awarded after a full vaccination cycle or recent recovery from COVID-19, and it allows access to different public places such as cinemas or restaurants and to travelling. In Poland, since July 1, digital international COVID-19 immunization certificates have been adopted, but they are only used during trips abroad, because no regulations were introduced that would allow them to be practically enforced inside the country. On the other hand, some reported findings suggest that vaccine passports resulted in autonomy frustration and might have detrimental effects on people’s motivation to get vaccinated, making them less likely to sign-up for a "booster" dose of the vaccine [
45,
46].
The two most important reasons for vaccination found among HCWs in our study were personal and familial protection. The same reasons were also key to the decision to vaccinate against COVID-19 for HCWs in other studies [
47,
48]. Moreover, an important motivation for the large group of respondents to our study was a general risk reduction and the prospective possibility of lifting personal restrictions. This factor was also very significant among those vaccinated in the 30–55 age group in Switzerland [
49].
On the other hand, there was a very low percentage of unvaccinated participants in our study. These individuals can be divided into two groups according to the definitions of SAGE experts (the Strategic Advisory Group of Experts on immunization): persons who delay taking the vaccine (3.5%) and those who refuse vaccination despite the availability of vaccines (5.3%) [
50,
51]. However, this definition does not take into account the concept of stress or fear of vaccination, although it indirectly concerns the trust in vaccination safety, which is an important element preventing willingness to accept the vaccine. In this study, every fourth N and NS experienced fear or objections before their vaccination. In the present study, most often both unvaccinated or still-hesitating subjects reported that they were afraid of the side effects and that the vaccine was not tested long enough. Those reasons cannot overwhelm the global efforts to control the COVID-19 pandemic by preventing the achievement of a high level of vaccination (at least 70% of immune individuals to obtain herd immunity and stop the spread of the virus in the population, and to protect people who cannot be vaccinated for medical reasons) [
52,
53]. Before each vaccination, the doctor collects an interview from the patient regarding medical contraindications for vaccination, but no one asks about anxiety before vaccination. This feeling of uncertainty about how one will feel after vaccination causes a build-up of stress and a reluctance to continue vaccination in the future.
The three most common reasons for not getting vaccinated in our study were the rapid completion of clinical trials, doubt concerning the efficacy of the vaccine, and fear of side effects. Our findings support prior studies that also are also concerned with healthcare professionals [
29,
54]. Skeptical attitudes towards new vaccines are mainly due to a perceived lack of testing for vaccine safety and efficacy [
28,
55]. The accelerated release of vaccines under emergency use authorization (EUA) rather than full FDA approval could be important causes for skepticism [
56]. Meanwhile, the occurrence of pre-vaccination stress among participants was one of the factors that significantly influenced the occurrence of APVRs and their duration (
Table 6 and
Table 7). Accurate information about possible side effects and how to deal with them can reduce the feeling of fear of vaccination, and here is the main role of HCWs—to know about vaccination and inform patients when they qualify for vaccination. The attitudes of HCWs related to COVID-19 vaccination are particularly important for enhancing vaccination uptake in general populations [
57].
More than two-thirds of vaccinated participants in the study reported side effects after receiving at least one dose of vaccine against COVID-19. An adverse event after the first dose of AstraZeneca was significantly more frequent than after the BioNTech/Pfizer vaccine, and inversely after receiving the second dose of these vaccines (
p < 0.001). The respondents more often rated the side effects after vaccination with the BioNTech/Pfizer vaccine (52%) as minimal vs. vaccination with the AstraZeneca vaccine (13%;
p < 0.05). Severe post-vaccination adverse events that forced individuals to stay home occurred more frequently after the AstraZeneca vaccine, and side effects were severe enough to force them to contact a GP three times more often than after vaccination with the BioNTech/Pfizer vaccine (
p < 0.05). These data translate into observations made in the general population. According to the GIS (Chief Sanitary Inspectorate) in Poland, by 15 April 2021 adverse post-vaccination reactions following the AstraZeneca vaccine were reported, of which 25 were very severe, 324 serious, and 2708 mild—while there was a total of 2576 adverse vaccine reactions following the BioNTech/Pfizer vaccine, including 101 severe, 397 serious, and 2078 mild [
11]. Side effects associated with COVID-19 vaccines by AstraZeneca and BioNTech/Pfizer have been also reported by 60% of those vaccinated in Saudi Arabia [
58]. It has been reported that the side effects associated with the COVID-19 vaccine are mild to moderate. Similar to our results, where less than 6% HCWs required consultation with a doctor, only 3% of the participants needed to see a doctor due to the side effects of the vaccines in the study of Alhazmi et al. [
58].
It can therefore be assumed that encouragement and support from employers in the form of a day or two off in case of feeling unwell after vaccination could prove to be an additional factor in convincing individuals to vaccinate. The benefits of vaccinating HCWs are much greater, even if they are given 1–2 days off after vaccination, than of unvaccinated HCWs still working with patients—especially because a significant number of people participating in the presented study declare several workplaces and, if infected, they pose an even greater threat for their patients.
It should also be considered that most APVRs were mild and transient, and vaccination, like any medical procedure, carries some risks—and in the case of mass vaccinations among populations of all ages, with various medical conditions, it is not surprising that there have also been noted very serious complications, such as thrombotic complications, post-vaccination heart failure, or anaphylactic shock. However, these cases are very rare. On the one hand, adverse events including anaphylaxis cases occurred in individuals with a documented history of hypersensitivity after COVID-19 vaccination [
59], but on the other hand, according to Nittner-Marszalska et al., 2021 [
60], vaccination with the BioNTech/Pfizer anti-COVID-19 vaccine was well tolerated by both persons with and without a history of allergy/anaphylaxis. The vast majority of the reported symptoms of hypersensitivity were localized. Furthermore, these cases, although incidental, should not be concealed, because concealing any information may only lead to the building of conspiracy theories, which will cause all the more fear and destroy confidence in vaccinations [
61]. This is all the more important as the current epidemiological situation may suggest that further doses of the vaccine will be required before the global COVID-19 pandemic is brought under control.
Additionally, some reports have revealed changes over time relative to vaccination against SARS-CoV-2 in society, which could be positively related to the number of individuals who have been already vaccinated. As the number of people vaccinated increases and the number of reports about the efficacy and safety of the COVID-19 vaccine increases, the acceptance rate for vaccines also increases [
62].
Limitations of This Study
The study has several limitations. A major limitation of our study is the time of survey release; our detailed analysis of post-vaccination effects could only concern two of the four vaccination type preparations available on the market, because, at the time of collecting the questionnaires, the remaining vaccines were not common and too low a percentage of HCWs were vaccinated with them for the results to be analyzed in detail. Most of the respondents who participated in the study got vaccinated and support vaccination. However, it is likely that unvaccinated staff may have been more reluctant to participate in the study and did not complete the questionnaires (out of 1200 questionnaires that were distributed, 1080 were completed).