Background
Health care workers (HCW) have an increased risk to acquire and transmit certain infectious diseases not only to colleagues but in particular to vulnerable patients, such as newborns and children [
1,
2]. Vaccination of medical professionals reduces the risk of infections, nosocomial transmission and helps to maintain health care delivery in times of disease outbreaks [
3], for instance during influenza season. The European Center for Disease Prevention and Control recognized health care professionals as most important source of vaccination information for the general population. But only when they are aware of vaccination plans and side effects, proper advice can be given to patients, which might help to overcome the phenomenon of the so-called vaccine hesitancy. The physician’s recommendations substantially influence the patients’ vaccination behavior making it obvious that the physician’s own vaccination habits might be a bias for their vaccination hesitancy [
4]. Pediatricians are the first contact for parents and their children when questions regarding vaccination schedules have to be discussed. Pediatricians themselves should have proper vaccination coverage. Only then, newborns and young children, who are of particular risk to encounter vaccine preventable diseases due to their incomplete vaccination status might have some passive protection.
Due to these factors national policies are implemented for occupational vaccinations of HCW [
5]. The Austrian ministry of health publishes an update of the vaccination recommendations every year. These vaccinations are, however, not mandatory, neither for the general population, nor for HCW. Austrian pediatricians are advised, but not legally bound, to vaccinate against diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps, rubella, varicella, hepatitis A, hepatitis B, meningococcus ACWY and meningococcus B, pneumococcus and seasonal influenza [
5].
Although these vaccinations are not mandatory by Austrian law, many hospitals and medical universities recently started to offer internships and positions only under the terms of positive immunization protection. The costs for these vaccinations are not reimbursed by the government, but some of the vaccines are offered by the employer for free or price-reduced. Thus, it might be speculated that HCW in Austria might reach a rather high vaccination coverage. That this is not the case at the moment is proven by a recent publication by Harrison et al., who found rather low immunization rates for certain vaccination preventable diseases in HCW of the Vienna General Hospital [
6].
As far as we know there are no data available on the vaccination coverage of health care professionals working in pediatric outpatient clinics in Austria. Therefore, we conducted a cross-sectional questionnaire study on the vaccination rates of pediatricians and their assistants in all Viennese pediatric practices and analyzed the impact of gender, profession (pediatrician vs. assistant) and type of outpatient clinic (private practices in comparison to pediatric outpatient clinics covered by the Vienna regional health insurance fund).
Discussion
Pediatricians are at higher risk to encounter vaccine preventable diseases in comparison to other medical professions due to the vulnerable patient group they are taking care of. Therefore, they are advised to be immunized against these diseases before starting their career in this field. The vaccines recommended for all HCW in pediatric clinics in Austria include diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps, rubella, varicella, hepatitis A, hepatitis B, meningococcus ACWY and meningococcus B, pneumococcus and seasonal influenza [
5]. However, we observed a rather broad range of vaccination rates for the different vaccines in our study. Measles, poliomyelitis and pertussis reached an immunization coverage above 95% representing the needed vaccination coverage for eradication of measles according to the World Health Organization [
7], which however is not reached in the general population in Austria underlined by the fact that 1 out of 3 15- to 30-year-olds lack the second measles vaccine [
8]. When these results are compared to a recent publication of HCW in the general hospital of Vienna substantial differences were identified. In line with our results Harrison et al. found high vaccination rates for poliomyelitis (93%) but rather low immunization protection for measles (59.8%) and pertussis (58.2%) [
6]. Hepatitis B vaccination was similar in both studies (93%). It might be expected that HCW in the same city, Vienna, should have comparable vaccination habits. One of the reasons for this discrepancy might be the participating cohort and the small sample size, being one of the major limitations of this study. Only 34.7% of all resident pediatricians returned the questionnaire compared to 58% of HCW in the study be Harrison et al. [
6]. It might be speculated that those pediatricians who follow a “pro-vaccination” attitude were more willing to answer the questionnaire, while other physicians who are more critical towards vaccine recommendations refused to participate. We intended to avoid this bias by ensuring anonymity to all participants but we cannot rule out some discrepancy.
In international comparison, the vaccination rates of the Viennese resident pediatricians score well. In France, a similar study was conducted among general physicians from the Loire region. Eighty-one percent of respondents stated to be immunized against poliomyelitis, 59% against pertussis, 73% against influenza, 87% against hepatitis B and 64% against measles [
9], while Greece data reported on a completed vaccination rate being rather low for measles (33% of HCW) and even lower for hepatitis A (5.8%). Interestingly, in this cohort, vaccination coverage was indirectly associated with age, as younger HCW received more vaccines than older [
10]. Hepatitis B vaccination is quite well accepted by HCW reaching an immunization rate between 75 and 100% according to the Venice II project report [
11], whereas HCW are much less willing to immunize against measles-mumps-rubella, which reached only 9.7% vaccination coverage in an Italian study [
3]. Data on the vaccination rates for meningococcus and pneumococcus are rare. In comparison to the results of Harrison et al. our data revealed a rather high vaccination coverage (32 to 49% respectively in comparison to 6.7%), which might be originated in the national recommendations in particular for pediatricians to receive these vaccines.
With regard to vaccination habits of medical personnel we identified differences in one of the investigated influenza seasons where significantly less assistants were immunized in comparison to pediatricians. This was also prominent for the pneumococcus vaccine. As assistants have close contact to pediatric patients they represent a potential source for transmission of these pathogens especially during winter season, when both pathogens are commonly present and put in particular newborns and infants at risk. Influenza vaccine is one of the least accepted vaccinations among medical professionals. In a US study, HCW in hospitals were immunized against influenza more often than resident physicians [
12]. This discrepancy was also prominent in our study with 70% of participants being vaccinated against influenza in comparison to 42% of Viennese health care professionals in the general hospital [
6]. The latter data are comparable to a Greece study, where 45.9% of HCW had a history of influenza vaccination at least once [
10], whereas in a Canadian study, even 69 to 76% of residents were vaccinated against influenza [
13]. In contrast, in the general population in Austria the influenza vaccination coverage is only around 5%. Thus, it is obvious that the vaccination coverage is far from the target of 75% to be achieved as stated in the EU council recommendation of 2009 [
14]. Pertussis vaccination follows a similar pattern. In Germany, 48.2% of university doctors but only 13.4% of nurses were vaccinated against pertussis in the past 10 years [
15]. Many of the HCW do not even know whether they received the vaccine, which might be due to its part as a combination vaccine with tetanus, poliomyelitis and diphtheria. This puts the patients at risk to encounter these bacteria, which is in particular dangerous for infants and newborns who are not protected by maternal antibodies and have not been vaccinated yet. A rise in pertussis cases was described in Austria in the recent years [
16] underlining the importance of a broad vaccination coverage.
One of the trends in Austria is to have their children checked by pediatricians working in private practices and not in government funded practices. Therefore, we were interested if the vaccination coverage of these two pediatric clinic types show comparable results. Only the immunization protection for hepatitis B was significantly lower in HCW of private practices. The reason for this phenomenon remains unclear and cannot be explained by this study.
The strength of our study is that it provides an insight into the vaccination habits of HCW in the pediatric field in Vienna. Making these data public might lead to an awareness of pediatricians not only in Vienna to get their vaccination status up to date. However, the study design is one of the limitations, as the data are only self-reported without any control of the actual vaccination documentation, which might lead to a bias of results. The reason for the rather low reply rate remains unclear. We guaranteed all participants anonymity but it might reflect the low value that vaccinations have for some HCW.