Vaccination: The Cornerstone of Occupational Health, Patient Safety

By Kelly M. Pyrek

The cornerstone of occupational health this time of year continues to be influenza vaccination, but compliance remains an ongoing challenge. Black, et al. (2017) report that 78.6 percent of survey respondents say they received vaccination during the 2016-17 season, similar to reported coverage in the previous three influenza seasons. To estimate influenza vaccination coverage among healthcare personnel (HCP) in the U.S. during the last influenza season, the Centers for Disease Control and Prevention (CDC) conducted an opt-in Internet panel survey of 2,438 HCP. The survey revealed that vaccination coverage continued to be higher among HCP working in hospitals (92.3 percent) and lower among HCP working in ambulatory (76.1 percent) and long-term care (LTC) (68 percent) settings.

As Black, et al. (2017) note, "As in previous seasons, coverage was highest among HCP who were required by their employer to be vaccinated (96.7 percent) and lowest among HCP working in settings where vaccination was not required, promoted, or offered on-site (45.8 percent). Implementing workplace strategies found to improve vaccination coverage among HCP, including vaccination requirements or active promotion of on-site vaccinations at no cost, can help ensure that HCP and patients are protected against influenza."

Regarding getting traction among healthcare workers relating to flu vaccination, William Schaffner, MD, professor of preventive medicine and health policy at Vanderbilt University, and National Foundation for Infectious Diseases (NFID) says, "I am encouraged but I think there is still work to be done. We have seen a gradual rise, year by year, in the proportion of healthcare workers that are vaccinated annually against influenza. The culture is changing, and I think that over time, the notion that this is a patient safety issue has begun to be understood."

According to Black, et al. (2017), vaccination coverage in 2016-17 was highest among physicians (95.8 percent), nurse practitioners and physician assistants (92.0 percent), nurses (92.6 percent), and pharmacists (93.7 percent), and lowest among other clinical HCP (80.0 percent), assistants and aides (69.1 percent), and nonclinical HCP (73.7 percent). However, in hospital settings, vaccination coverage was approximately 90 percent or higher in all occupational groups, including assistants and aides, as well as non-clinical personnel.

Vaccination authority has been supported by law in schools and pharmacies that administer vaccines, and the same is true for healthcare. However, in all settings and in all states, there are medical exemptions, and a majority of states allow religious and/or philosophical exemptions. It has been a number of years since the advent of healthcare institutions mandating influenza vaccination of healthcare workers, and as Field (2009) reminds us, "No one is at greater risk of contracting contagious diseases or of spreading them than healthcare workers. Those who work in hospitals regularly encounter patients as an essential part of their jobs. Disease-causing organisms can easily spread from patients to healthcare workers and then back to other patients on a hospital floor. The result is a group of healthcare workers who are out sick and unable to do their jobs, as well as a group of patients with a new disease that they did not have when they were admitted. The solution, in the view of most public health officials, is to have all healthcare workers vaccinated."

Black, et al. (2017) found that overall, 42.3 percent of HCP reported a requirement to be vaccinated for the 2016–17 season, an increase over the 2013-14 season but similar to the 2014-15 and 2015-16 seasons. HCP working in hospitals were more likely to report a vaccination requirement (69.5 percent) than were HCP working in ambulatory care (39.0 percent), LTC (26.2 percent), or other clinical settings (22.0 percent). HCP working in ambulatory care, LTC, and other clinical settings more often reported that their employer did not require, provide, or promote vaccination (21.7 percent, 30.5 percent, and 32.2 percent, respectively), compared with HCP working in hospital settings (3.9 percent). As in previous seasons, vaccination coverage in 2016–17 was highest (96.7 percent) among HCP working in settings where vaccination was required, ranging from 90.0 percent in LTC settings to 98.3 percent in hospital settings. Among HCP whose employers did not have a requirement for vaccination, coverage was higher among those who worked in locations where vaccination was available at the worksite at no cost for >one day (80.3 percent) than among those with vaccination available for one day only (73.8 percent) or among those who worked in locations where their employer did not provide influenza vaccination on-site at no cost but actively promoted vaccination through other mechanisms (70.4 percent). Vaccination coverage was lowest (45.8 percent) among HCP working in locations where employers did not require vaccination, provide vaccination on-site at no cost, or promote vaccination.

Mandatory vaccination of healthcare workers begs the question of the efficacy of the vaccines themselves. "Although the data are not perfect, and they never will be, there are now sufficient data that vaccines do work," says Schaffner. "So, if you immunize healthcare workers, we know that patients will be protected. There is the acknowledgement that although the influenza vaccine is not perfect, it is a good vaccine and always provides some protection; we can't expect more than the currently available vaccines can deliver. I always like to paraphrase that old French philosopher Voltaire who reminded us that waiting for perfection is the great enemy of the current good, and we can do a lot of good with our pretty good influenza vaccine. In medicine, in all phases, from birth to death, there are hardly any things that we do that are perfect, but they are all for the good of the patient. So, we recognize that we don't always achieve 100 percent protection, but we can achieve substantial protection."

Schaffer continues, "The list of professional organizations and societies that have endorsed mandatory healthcare worker immunization is very long, and if you couch this as an infection control measure, it is a patient safety imperative.  With the added weight of professional organizations behind it, the general sense has been that if it comes to a legal challenge, the infection control aspect of this carries the day -- because it's not being done to protect the individual healthcare worker the way it is for the average citizen, it is being done as an infection control measure to benefit the health of patients. And in that sense, the law has, for all intents and purposes, uniformly said institutions can make those rules and enforce compliance on behalf of the patient."

As Field (2009) observes, "Hospitals have tried numerous techniques to increase voluntary immunization among their patient-care staffs. Some hospitals use roving carts that bring vaccines to nursing stations, or vaccines might be brought to staff meetings. In some facilities, vaccine decliners must sign statements acknowledging the risk they are assuming for themselves and for their patients, or they might have to wear surgical masks during flu season. The goal of all these measures is to make vaccination as convenient-and avoidance of vaccination as inconvenient-as possible. Unfortunately, while these efforts to achieve voluntary compliance tend to increase vaccine uptake somewhat, they still leave vaccination rates below 50 percent. The only approach that has generated near-total compliance is mandatory vaccination consisting of an ultimatum to health care workers that they either receive a vaccine or lose their job. Limited exceptions are permitted for individuals known to be at heightened risk for side effects, such as allergies to vaccines, and for those with clear religious objections."

The Centers for Disease Control and Prevention (CDC), the Advisory Committee on Immunization Practices (ACIP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) recommend that all U.S. healthcare workers get vaccinated annually against influenza. Additionally, Chapter 7 of the National Action Plan to Prevention Health Care-Associated Infections: Road Map to Elimination from the Department of Health and Human Services (HHS), which supports the influenza vaccination of healthcare personnel to protect healthcare personnel and their patients, as well as to reduce disease burden and healthcare costs.
As Black, et al. (2017) remind us, "Federal reporting requirements might influence vaccination coverage by occupational setting. CDC’s National Healthcare Safety Network (NHSN) has included reporting of healthcare personnel influenza vaccination since 2012. During 2013–2015, the Centers for Medicare & Medicaid Services (CMS) added requirements to report health care personnel influenza vaccination data through NHSN for acute care hospitals (2013), ambulatory surgery centers (2014), and outpatient hemodialysis facilities (2015), among other settings. LTC facilities currently are not covered by CMS quality reporting requirements. LTC employers can use the LTC web-based toolkit developed by CDC and the National Vaccine Program Office, which provides access to resources, strategies, and educational materials for increasing influenza vaccination among HCP in long-term care settings."

In 2013, the policy of mandatory vaccination got a boost from the Infectious Diseases Society of America (IDSA), the Society for Healthcare Epidemiology of America (SHEA), and the Pediatric Infectious Diseases Society (PIDS) called for mandatory, universal immunization of healthcare personnel. Existing recommendations for healthcare workers from the ACIP include vaccination against influenza, measles, pertussis (whooping cough), hepatitis B, and varicella (chicken pox). As IDSA/SHEA/PIDS noted in a 2013 statement, "Some voluntary health care personnel vaccination programs have been effective when combined with strong institutional leadership and robust educational campaigns. However, for the vast majority of facilities, mandatory immunization programs are necessary to achieve target immunization rates. The policy calls for documentation of immunity or receipt of recommended vaccinations as a condition of employment, unpaid service, or receipt of professional privileges." Daniel Diekema, MD, who was president-elect of SHEA at the time, stated, "ACIP-recommended vaccines are proven to be safe, effective and cost-saving. Although there may be exceptions made for individuals for whom vaccination is not appropriate or in circumstances when the vaccine is not available, these exceptions should be extremely rare.” Notably, the IDSA/SHEA/PIDS policy does not provide for exemptions based on personal belief or religion.

Goodman and Webster (20110), on behalf of the American Bar Association (ABA), affirm that the origins of mandatory influenza vaccination of healthcare workers are in New York in August 2009, when the NY State Hospital Review and Planning Council adopted an emergency regulation mandating the vaccination of healthcare workers for seasonal and H1N1 influenza. At the time, New York State Commissioner of Health Richard F. Daines pointed to the statistic that voluntary vaccination only resulted in staff immunization rates of 40 percent to 50 percent, noting that, "… medical literature convincingly demonstrates that high levels of staff immunity confer protection on those patients who cannot be or have not been effectively vaccinated." The mandate required all New York healthcare workers to receive the seasonal and H1N1 influenza vaccine by Nov. 30, 2009, or be terminated from employment unless the vaccine was medically contraindicated." They add, "In the end, New York did not enforce mandatory vaccination of HCW for H1N1 due to a vaccine shortage."

Field (2009) acknowledges the bumpy start on the road toward mandatory vaccination of healthcare workers: "New York State was the first in the nation to try to mandate vaccination as a matter of law, but the effort proved to be short-lived. The Department of Health issued a rule that would have barred workers who declined either seasonal or H1N1 influenza vaccination from assignments involving patient contact in any hospital, outpatient clinic or home-care program. However, a group of nurses sued and obtained a restraining order suspending enforcement. Subsequently, the Department, citing vaccine shortages, withdrew the proposal. For the most part, unions representing nurses have been vocal in opposing vaccine mandates. Although they generally support voluntary vaccination and strongly encourage their members to comply, they believe that each health care worker should be entitled to make his or her own decision. They point out that all vaccines can pose risks. Even for people without allergies, hazards may lurk in additives, such as thimerosal, a mercury-based preservative used in some vaccines."

As Field (2009) explains, "Mandate opponents also frame the issue as one of rights. Should health care workers have less freedom than others to decide what health risks they choose to accept? Should entering the nursing profession turn a person into a second-class citizen? In the end, mandates may have the unfortunate effect of driving some people away from working in healthcare. The power of the government to mandate vaccination has long been recognized by the Supreme Court. In the landmark 1905 case of Jacobson v. Massachusetts, the Court upheld an ordinance in Cambridge, Mass., that required all adult citizens to be vaccinated against smallpox in the wake of an epidemic. The court found that notwithstanding the Constitution’s guarantee of liberty, every person may be subject to 'manifold restraints' when needed 'for the public good.' This broad ruling gives healthcare workers limited legal ground to object. Moreover, most states recognize the doctrine of employment-at-will, under which employers can terminate a worker for any reason as long as a prohibited motivation, such as race or disability status, is not involved. In the absence of a proscribed rationale, vaccination can be used as a condition of continued employment."

There was an exception to the employment-at-will doctrine for collective bargaining agreements that limit an employer’s hiring discretion. In 2006, the Washington State Nurses Association sued Virginia Mason Hospital in Seattle, which sought to require nurses to receive seasonal flu vaccine. The union claimed that a collective bargaining agreement prohibited new workplace rules without its consent. An arbitrator upheld the union’s right to veto the vaccine requirement, and the decision was affirmed in court. However, the hospital   reinstituted the mandate for all employees except unionized nurses, Field (2009) reported.

Field (2009) takes the stance that many healthcare experts do when it comes to weighing the balance between healthcare worker rights and the rights of patients: "Public health officials frame the issue of vaccine mandates for healthcare workers as one of patient safety. Studies have shown higher patient death rates in hospitals with a smaller percentage of vaccinated employees. From this perspective, the freedom of workers to make decisions regarding their own health should carry less weight than the well-being of people who depend on them for care. The goal of public health is to safeguard the population at large, and this is where priorities must lie." Field (2009) emphasizes that, "A guarantee of complete vaccine safety is never possible, but protection of public health often involves a balancing of risks," noting that flu-related morbidity and mortality "far outweighs the much smaller risk of adverse vaccine effects."

Field (2009) further asserts that "Mandated medical interventions, such as vaccination, should never be imposed capriciously; however, patient contact involves unavoidable risks and special obligations. Professionals who care for patients accept an overriding ethical imperative embodied in the Hippocratic Oath that new physicians take-first, do no harm. Unvaccinated workers who spread the flu can cause tremendous harm. This is especially true when vulnerable patients, such as those in intensive care units, are involved. Patients should have the right to expect that their hospital will take every reasonable precaution to protect them from developing a new disease that they did not have upon admission. With regard to the flu and many other contagious diseases, vaccination is the best way to honor this right. Although voluntary compliance by healthcare professionals would be preferable to mandates, its lack of effectiveness, at least so far, leaves hospitals and public health officials with little choice."

In a recent blog on the website of the Office of Disease Prevention and Health Promotion (ODPHP), Linda R. Greene, RN, MPS, CIC, FPIC, president of the Association for Professionals in Infection Control and Epidemiology (APIC), points out that "healthcare worker influenza vaccination rates have risen only minimally over the past 20 years and are far short of U.S. Department of Health and Human Services Healthy People 2020 goals whose target is a 90 percent vaccination rate."  She adds, "One of the fundamental tenets of healthcare is to care for patients while protecting ourselves from harm. Because HCWs work in an environment where frequent contact with infectious patients is routine, we are at risk for exposure to influenza with possible transmission to other patients, their families, and other HCWs. The situation calls for a review of attitudes and beliefs toward influenza vaccination with a focus on the successful strategies associated with increased HCW vaccination rates."  Greene cites the example of Loyola University Medical Center in Chicago, which, in 2009, mandated flu vaccination as a condition of employment, and extended this mandate to students, volunteers and contractors. According to Loyola's Jorge Parada, MD, MPH, FACP, FIDSA, in the first year of the mandatory policy (2009-2010), 99.2 percent of employees received the vaccine, 0.7 percent were exempted for religious or medical reasons, and 0.1 percent refused vaccination and chose to terminate employment. The results were sustained: in 2012, 98.7 percent were vaccinated, 1.2 percent were exempted, and 0.06 percent refused vaccination. In a statement, Parada noted, “Near-universal flu immunization is achievable and sustainable with a mandatory vaccination policy. Our employees and associates now understand that this is the way we do business. Just as construction workers must wear steel-toed boots and hard hats on job sites, healthcare workers should get a flu shot to work in a hospital. We believe that patient and staff safety have been enhanced as a result.”

As Greene notes in the ODPHP blog, "One example of successful strategies to motivate staff was highlighted by Mary Ellen Scales, RN, MSN, CIC, FAPIC, who was recognized as a Hero of Infection Prevention by APIC in 2009. She is chief infection control officer for Baystate Health System in Springfield, Mass. Seeing that only 40 percent of the facility’s staff had been vaccinated prior to the fall of 2006, she developed the Flu Vaccine Champion Program to improve staff participation. The program consisted of 68 unit-based staff members who motivated fellow employees in their areas to sign up and administer the vaccine. Within two years, the center’s participation rate doubled to 80 percent. Her flu immunization compliance rate this past year was 97 percent. Mary Ellen received an award for achievement in adult immunization from MASSPRO, a state organization dedicated to improving healthcare quality. The stories of Mary Ellen and other champions are numerous and continue to inspire and motivate us. Hopefully, we will take this opportunity to stop and think about our duty of care to protect our patients from harm. Those entrusted to our care deserve no less."

Vanderbilt University's Schaffner relates a similar experience at his institution. "In this context of changing culture and expectations in what the norms are, it is quite clear that institution by institution, hospitals and large clinics have begun to adopt some form of mandatory immunization for employment. The expectation is, that everyone will be vaccinated unless they have specific medical or other contraindications. I say some form or flavor because mandatory should always appear in quotes because the variations of what mandatory means depends upon the institution. But what it usually means is that everyone must seriously consider becoming vaccinated and if not, they have only very specific options for declining immunization, and that certainly has been a big change in my own institution, where mandatory means that we review the reasons for declination very carefully -- we have a set number of reasons that are acceptable, and if not, those individuals are, shall we say, strongly encouraged to be vaccinated. We don’t fire people but we do everything but -- and we have moved from a voluntary program which was enthusiastically embraced by the administration and enthusiastically administered by our occupational health team with the help of infection control and others and we would barely get above 70 percent. Once we went to our flavor of mandatory, we are up over 90 percent. So, that extra push, the requirement to come forth with a reason, and then if the reason is not one that is on the approved list, you get counseling and almost always, we get compliance. As this has rolled out over the last several years, it has become the norm and we must address fewer and fewer requests for declination. Because everyone knows we do this every fall."

Hayward (2017) acknowledges that investigators have attempted to demonstrate the impact of influenza vaccine in healthcare workers on patient outcomes. In his study, Hayward aimed to test the hypothesis that a campaign promoting influenza vaccination of staff would reduce influenza-related morbidity and mortality in elderly residents of long-term care facilities. The study was based in a national chain of LTCF providing 24-hour nursing care. The researcher hypothesized that the effect of the vaccine would be confined to periods when influenza was circulating and undertook the study over two years to minimize the risk of being unable to demonstrate an effect in a year with low levels of influenza circulation. The study took place over two winter seasons, the first of which had considerably higher levels of community influenza activity and influenza related deaths than the second. During the period of more intense influenza circulation Hayward (2017) found highly statistically significant reductions in residents’ influenza-like illness, GP consultations for influenza like illness, hospitalizations with influenza-like illness, and all-cause mortality.

As Hayward (2017) explains, "We found no significant decreases in any of our outcomes during periods when influenza was not circulating in the community or in the second year when influenza rates were substantially lower than the first. In our discussion, based on our own findings and those from other studies, we concluded that healthcare worker vaccination provides an important level of resident protection in long-term care facility settings. While we claimed that the findings may be generalizable to other settings we did not intend to imply that the extent of the benefit would be similar in other settings. Indeed, we think the effect is likely to be substantially greater in long-term care facilities for frail elderly residents than in the acute care setting or in long term care facilities catering for less frail patients."

Mandatory vaccination of healthcare workers hinges in part upon efficacy of immunization, but a study published in PLOS One earlier this year fueled the ongoing debate about vaccine effectiveness, as the team of researchers concluded that the research used to justify mandatory influenza vaccination is flawed and that this mandate does not produce the protective benefits that had been assumed previously. In their study, De Serres, et al. (2017) critiqued and quantified the cRCT evidence for indirect patient benefit underpinning policies of mandatory healthcare worker influenza vaccination.

As the researchers explain, "Plausibility of the four cRCT findings attributing indirect patient benefits to HCW influenza vaccination was assessed by comparing percentage reductions in patient risk reported by the cRCTs to predicted values. Plausibly predicted values were derived according to the basic mathematical principle of dilution, taking into account HCW influenza vaccine coverage and the specificity of patient outcomes for influenza. Accordingly, predicted values were calculated as a function of relevant compound probabilities including vaccine efficacy (ranging 40 percent to 60 percent in HCWs and favorably assuming the same indirect protection conferred through them to patients) × change in proportionate HCW influenza vaccine coverage (as reported by each cRCT) × percentage of a given patient outcome (e.g. influenza-like illness (ILI) or all-cause mortality) plausibly due to influenza virus. The number needed to vaccinate (NNV) for HCWs to indirectly prevent patient death was recalibrated based on real patient data of hospital-acquired influenza, with adjustment for potential under-detection (5.2-fold), and using favorable assumptions of HCW-attributable risk (ranging 60 percent to 80 percent)."

De Serres, et al. (2017) found that, in attributing patient benefit to increased HCW influenza vaccine coverage, each cRCT violated the basic mathematical principle of dilution by reporting greater percentage reductions with less influenza-specific patient outcomes (i.e., all-cause mortality > ILI > laboratory-confirmed influenza) and/or patient mortality reductions exceeding even favorably-derived predicted values by at least 6- to 15-fold.The researchers report, " If extrapolated to all LTCF and hospital staff in the United States, the prior cRCT-claimed NNV of 8 would implausibly mean >200,000 and >675,000 patient deaths, respectively, could be prevented annually by HCW influenza vaccination, inconceivably exceeding total US population mortality estimates due to seasonal influenza each year, or during the 1918 pandemic, respectively. More realistic recalibration based on actual patient data instead shows that at least 6,000 to 32,000 hospital workers would need to be vaccinated before a single patient death could potentially be averted." The researchers conclude, "The four cRCTs underpinning policies of enforced HCW influenza vaccination attribute implausibly large reductions in patient risk to HCW vaccination, casting serious doubts on their validity. The impression that unvaccinated HCWs place their patients at great influenza peril is exaggerated. Instead, the HCW-attributable risk and vaccine-preventable fraction both remain unknown and the NNV to achieve patient benefit still requires better understanding. Although current scientific data are inadequate to support the ethical implementation of enforced HCW influenza vaccination, they do not refute approaches to support voluntary vaccination or other more broadly protective practices, such as staying home or masking when acutely ill."

Hayward (2017), taking issue with the De Serres study, challenges several points: "De Serres, et al. assert that the cluster-randomized trials violate the principle of dilution whereby the greatest reductions should be observed in the most specific outcomes (e.g. greater relative reductions would be expected for laboratory confirmed influenza than for all-cause mortality). Since the studies were not adequately powered to assess which outcomes had the greatest reductions and the confidence intervals for all outcomes overlap we do not agree that the studies individually or collectively violate this principle. For example in our study the reduction in influenza like illness was greater than the reduction in GP consultations for influenza like illness which was in turn greater than the reduction in hospitalizations with influenza like illness. The point estimate of the reductions in all cause mortality (5 fewer deaths per 100 residents) was greater than that for hospitalizations related to influenza like illness (2 fewer hospitalizations per 100 residents). According to De Serres et al this would violate the principal of dilution. However, the confidence intervals for these measures overlap considerably, indicating that we do not know which measure had the greatest reduction."

Hayward (2017) continues, "De Serres, et al. highlight that a high proportion of averted deaths were not labelled as deaths with influenza like illness. We do not think this makes our results less plausible firstly because many deaths will have occurred in hospital but were reported by nursing home staff so they will not have been able to assess whether they had influenza like illness at the time of death. Secondly influenza may trigger a chain of events leading to death but at the time of death such patients may no longer have an influenza like illness. Since our data were collected as aggregate total event numbers for each outcome we cannot tell how many of those who died had a recent influenza like illness. Thirdly the symptomatology of influenza may be very vague in the frail elderly with multiple co-morbidities, especially as they approach death. Finally, as discussed above, the statistical uncertainty around estimates of effect mean that whilst we can be confident that there was a highly significant reduction in all-cause mortality we do not know whether this represents a greater reduction than that in influenza like illness deaths. We therefore reject De Serres’ assertion that these are paradoxical findings or that they should “reinforce concerns about the reliability and validity of the study’s conclusions.”

De Serres, et al. emphasize that in some trials, protective effects were also observed outside the time period when national surveillance detected influenza activity. As Hayward (2017) objects, "We found no effect of the intervention for any of our outcomes outside the period of influenza circulation, strengthening the credibility of our results. However, it should be noted that influenza surveillance only picks up the tip of the iceberg of influenza activity such that early community transmission may be missed. Periods of circulation identified through national level surveillance often do not coincide with periods of circulation identified at local level. Sporadic outbreaks of influenza have also been observed in LTCFs outside normal periods of influenza circulation. Consequently, the fact that other studies found some of the protective effects outside the period when national surveillance indicated circulation of influenza does not mean their results are implausible." He adds, "De Serres, et al.’s main criticism is that if the numbers needed to vaccinate (NNV) to prevent one death in our study were extrapolated to all LTCF staff in the U.S. the number of deaths averted would be considerably greater than the annual number of deaths estimated to be due to influenza in the U.S. Also, if extrapolated to all hospital healthcare workers in the U.S. the predicted number of deaths averted would exceed the number of influenza deaths in the U.S. during the 1918 pandemic. While we proposed that the concept of staff vaccination protecting patients was generalizable to other settings we did not claim that the estimate of the NNV would be equivalent in other settings, indeed we think it self-evident that this would not be the case.
Hayward (2017) continues, "Doubtless, the debate as to whether or not staff influenza vaccination should be a condition of employment will continue. If avoiding patient death was the sole aim of staff vaccination a reasonable economic case could be made for staff vaccination in hospital settings at the NNV estimated by De Serres (influenza vaccine costs less than $2 per dose). When factoring in the prevention of unnecessary illnesses in patients and staff, associated health service costs and the avoidance of staff sickness absence, the economic case is still more compelling. Economic arguments cannot, however, indicate a level of protection at which vaccination should be made a condition of employment. Regardless of such enforcement measures healthcare workers need to consider their professional duty to take reasonable actions to protect their patients from infection. De Serres, et al. argue that more broadly protective practices, such as staying home or masking when acutely ill could be alternative approaches to protection, but unlike staff vaccination the effectiveness of these measures has not been assessed. The fact that viral shedding precedes symptom onset by around 24 to 48 hours, that many people with laboratory-confirmed influenza have mild symptoms that may be hard to distinguish from the common cold and that many infections are asymptomatic would minimize the effectiveness of such measures. Avoiding influenza through vaccination is an important approach for healthcare workers to take to avoid unnecessarily passing infection on to their vulnerable patients."

Vanderbilt's Schaffner weighs in on the debate. "Our good colleagues in Canada and elsewhere looked over the data and they told us what we knew already, mainly that influenza vaccines are not perfect," he says. "They looked at the same data I looked at, and I thought our jar was half full. They chose to put the emphasis on the fact that the jar was half empty. I thought their analysis was as far as it went, was correct but a little precious, and they set up some standards, as I recall from that paper, of the achievement of 100 percent protection and I said, there is no one that I know of who anticipates that we will get anything close to that, so it's an unreasonable standard, given where the science of influenza vaccines is today. We have to do always, the best with what we are given today, the tools that we have today must be applied the best possible way to provide, as John Stuart Mill told me in my basic philosophy class, "the greatest good for the greatest number," and you don’t do that by not vaccinating people."

The De Serres and Hayward debate is nothing new, as a 2013 analysis found limited evidence for healthcare worker flu vaccination. Ahmed, et al. (2013) conducted a systematic review of randomized trials, cohort studies, and case-control studies published through June 2012 to evaluate the effect of healthcare personnel influenza vaccination on mortality, hospitalization and influenza cases in patients of healthcare facilities. The researchers identified four cluster randomized trials and four observational studies conducted in long-term care or hospital settings. Pooled risk ratios across trials for all-cause mortality and influenza-like illness were 0.71 and 0.58, respectively; pooled estimates for all-cause hospitalization and laboratory-confirmed influenza were not statistically significant. The cohort and case-control studies indicated significant protective associations for influenza-like illness and laboratory-confirmed influenza. No studies reported harms to patients. They reported that the quality of the evidence for the effect of healthcare personnel vaccination on mortality and influenza cases in patients was moderate and low, respectively; the evidence quality for the effect of healthcare worker vaccination on patient hospitalization was low; and the overall evidence quality was moderate.

Nurses are certainly paying attention to the studies debating vaccine effectiveness. In a study in which the reasons why nurses decline influenza vaccination were explored, Pless, et al. (2017) found that nurses doubted the authenticity of studies showing the efficacy of influenza vaccine. The researchers conducted in-depth interviews with 18 nurses from a range of fields, positions in organizational hierarchy and work experience in Swiss hospitals. They quote one nurse as saying, "… I don't believe a thing anymore. In all these years "oh what has been proven…" and the next day there's a new doctor and a new thing, a new study and then everything is just cold coffee again, to put it simply but that's how I experienced it in all these years and that's why I don't believe anything anymore, that somebody just tells me.”

Pless, et al. (2017) also discovered three interconnected themes: "Firstly, the idea of maintaining a strong and healthy body, which was a central motif for rejecting the vaccine. Secondly, the wish to maintain decisional autonomy, especially over one's body and health. Thirdly, nurses' perception of being surrounded by an untrustworthy environment, which restricts their autonomy and seemingly is in opposition to their goal of maintaining a strong and healthy body."
As the researchers note. " While some interviewees did not perceive influenza as a threat to their health and well-being and therefore did not find a vaccination necessary, others felt the vaccine would not promote their health, due to lack of efficacy, or would even harm their health due to negative side-effects or a weakening effect on the immune system. Nearly all the nurses expressed the belief that influenza did not pose a threat for them since they were healthy, did not belong to the high-risk population and had never before fallen ill with influenza. They therefore found it unnecessary to get the vaccination. Fear of side effects was also a commonly stated theme. Some nurses had felt ill after having been vaccinated against influenza in the past. This ranged from feeling sick for a couple of days to one nurse who recalled whole months of being unwell after she had been vaccinated… Participants appeared to ascribe these negative effects to the influenza vaccination and some reported that they based their decision not to get vaccinated on a negative experience they had more than a decade ago. Ten of the nurses had never been vaccinated against influenza before and therefore had no personal experience. However, nearly all the nurses had observed side effects in colleagues or family members or heard about such cases from hearsay. This seemed to be a very current topic and often discussed among colleagues … Others reported negative experiences with vaccination or medication in general, which had nothing to do with the influenza vaccine, but which led to their reluctance to get vaccinated … The right to bodily integrity and self-determination were cited universally by nurses as crucial issues … Furthermore, some nurses saw it as their right to become ill and stay at home, especially since they did so much for others at work. They did not want this perceived right to fall ill to be taken from them by their superiors: “When that began I also had the idea…well that one should have the right to be ill, so to speak. That if there`s too much stress at work that you don`t have as much immune resistance…that you can stay at home for a week and don`t have to go to work by all means.”

As the researchers conclude, "Nurses tend to rely on conventional health beliefs rather than evidence based medicine when making their decision to decline influenza vaccination. Interventions to increase influenza vaccination should be tailored specifically for nurses. Empowering nurses by promoting decision-making skills and by strengthening their appraisal may be important factors to consider when planning future interventions to improve vaccination rates. The teaching of evidence-based decision-making should be integrated on different levels, including nurses' training curricula, their workspace and further education."

As the debate over mandatory vaccination and vaccine efficacy continues, there are a number of other clinical interventions that can be implemented alongside vaccination to help boost infection prevention and control efforts, especially during flu season. A position paper from APIC indicates that mandatory vaccination should be part of a comprehensive program that includes education and other infection prevention measures such as hand hygiene, respiratory etiquette and standard precautions. As APIC's Greene notes in the ODPHP blog, "Although mandatory policies have improved vaccination rates, they fall short - in the absence of other strategies - of embedding the importance of influenza vaccination into our internal beliefs, values, and sense of duty of care."

"Each of the other interventions besides vaccines, such as hand hygiene, PPE and respiratory etiquette, is not perfect, but each makes its contribution," says Vanderbilt University's Schaffner. "Staying home when you think you have the flu makes its contribution, of course, however, viral shedding can occur before symptoms begin and so we don't absolutely know when we have influenza. We may come to work with the sniffles and it might actually be the flu virus but because we may be young and healthy, we may not even know we have a mild case of flu. Each of these interventions contributes to the goodness, although each one of them has its own limitations."

Schaffner recommends that healthcare institutions make vaccination a priority and infection preventionists play a key role in this effort. "The first thing they can do is be sure they get vaccinated. And be dramatically and publicly vaccinated, so if there is an opportunity to be in the hospital newsletter, everyone showing with a smile that they have been vaccinated, that's very important. Also, they can talk it up on every occasion. They can be informed to sit and be willing to answer questions and make themselves available. They can work closely with their occupational health service so that everyone is on the same page and they can be seen to be working together. All of those things are exceedingly important."

References:
Ahmed F, Lindley C, Allred N, et al. Effect of influenza vaccination of health care personnel on morbidity and mortality among patients: systematic review and grading of evidence. Clin Infect Dis. Sept. 17, 2013.
Black CL, Yue X, Ball SW, Fink R, de Perio MA, Laney S, Williams WW, Lindley MC, Graitcer SB, Lu PJ, Devlin R and Greby SM. Influenza Vaccination Coverage Among Health Care Personnel - United States, 2016-17 Influenza Season. MMWR. Vol. 66, No. 38. Sept. 29, 2017.
De Serres G, Skowronski DM, Ward BJ, Gardam M, Lemieux C, Yassi A, Patrick DM, Krajden M, Loeb M, Collignon P and Carrat F. Influenza Vaccination of Healthcare Workers: Critical Analysis of the Evidence for Patient Benefit Underpinning Policies of Enforcement. PLOS One. Jan. 27, 2017. https://doi.org/10.1371/journal.pone.0163586
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Hayward AC (2017) Influenza Vaccination of Healthcare Workers Is an Important Approach for Reducing Transmission of Influenza from Staff to Vulnerable Patients. PLoS ONE 12(1): e0169023. Jan. 27, 2017. https://doi.org/10.1371/journal.pone.0169023. Accessed at: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169023
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Summary of the MMWR report, Influenza Vaccination Coverage Among Health Care Personnel - United States, 2016–17 Influenza Season:
Q: What is already known about this topic?
A: The Advisory Committee on Immunization Practices recommends annual influenza vaccination for all healthcare personnel (HCP) to reduce influenza-related morbidity and mortality in healthcare settings. For the 2015-16 influenza season, the estimated overall influenza vaccination coverage among healthcare personnel was 79.0 percent.
Q: What is added by this report?
A: Influenza vaccination coverage among HCP during the 2016-17 influenza season, assessed using an opt-in Internet panel survey, was 78.6 percent, similar to coverage during the 2015-16 season. Employer vaccination requirements and offering vaccination at the workplace at no cost were associated with higher vaccination coverage. Occupational settings with the lowest influenza vaccination coverage were the least likely to require vaccination or provide vaccination on-site at no cost.
Q: What are the implications for public health practice?
A: Employer vaccination requirements or, in the absence of requirements, offering influenza vaccination on-site at no cost, can achieve high HCP vaccination coverage. Implementing comprehensive evidence-based worksite intervention strategies is important to ensure HCP and patients are protected against influenza.
Source: Black, et al. (2017)