摘要：Annual influenza vaccination for health care workers has the potential to benefit health care professionals, their patients, and their families by reducing the transmission of influenza in the health care setting. Furthermore, staff vaccination programs are cost-effective for health care institutions because of reduced staff illness and absenteeism. Despite international recommendations and strong ethical arguments for annual influenza immunization for health care professionals, staff utilization of vaccination remains low. We have analyzed the ethical implications of a variety of efforts to increase vaccination rates, including mandatory influenza vaccination. A program of incentives and sanctions may increase health care worker compliance with fewer ethical impediments than mandatory vaccination. IT IS GENERALLY ACCEPTED that vaccinating health care workers against influenza reduces the transmission of the virus in health care settings, decreases staff illness and absenteeism, and indirectly benefits patients by decreasing their chance of being infected. 1 There are also very few risks associated with influenza vaccination, with the most frequently reported side effect being mild pain or swelling at the injection site. The results of a randomized double-blind controlled trial conducted over three consecutive years showed that localized pain or swelling following influenza vaccination was generally rare and that there were no absences from work because of vaccine-adverse events in the study population. 2 Influenza vaccination programs for health care workers are cost-effective in both direct medical costs and indirect costs of staff absenteeism. 2 Vaccinating employees and reducing absenteeism can save employers US $2.58 for every dollar invested in an influenza vaccination program. 3 The influenza vaccine is approximately 80% effective in healthy adults, with the effectiveness being even higher when there is a close match between the vaccine and the circulating strain of the virus. 4 Evidence on whether vaccinating health care workers against influenza is beneficial for patients has been surprisingly inconclusive. For example, a recent systematic review had equivocal findings on the effect of staff vaccination on the rates of influenza among elderly patients. 5 There have been a number of smaller, recent studies that have shown some improvement in patient outcomes when staff were immunized against influenza. 6 , 7 In all studies, the quality of evidence is undermined by relatively low levels of vaccination among health care workers, even in intervention groups. For example, Carman et al.'s study in long-term-care geriatric hospitals across west and central Scotland found that the vaccination rate for health care workers was only 50.9% compared with 4.9% when it was not explicitly offered. 6 There is evidence that vaccinating healthy people younger than 60 years (which includes health care workers) results in decreases of influenza cases among those groups. 5 Reduction in virus transmission may be particularly important in institutions and wards caring for young children, immunocompromised individuals, or the elderly. The vaccine is only 60% to 70% effective for individuals 65 years and older; despite approximately 80% of this population being immunized against influenza, 8 they remain susceptible to infection if exposed to the virus. In elder-care settings, influenza among staff precedes illness among residents, suggesting that health care workers introduce the virus into the setting. 9 These findings highlight the fact that, despite the value of vaccination, health care workers are notoriously noncompliant with vaccination regimes. International guidelines recommend annual vaccination for all health care workers with patient contact, 10 but worldwide, rates of influenza immunization among health care workers range between 2% and 60%, 11 well below the 83% to 94% required for the whole population to be resistant to spread of an influenza virus. 12 Health care institutions have used a variety of methods to increase immunization rates among employees, including education, reminder notices, small incentives, easy access to free vaccination, active promotion within the workplace, and compulsory vaccination as a condition of employment. 13 – 19 Most of these programs have achieved only small increases in vaccination rates, apart from employment-related mandatory vaccination. 19 For example, a program in Australian Capital Territory elder-care facilities included the provision of reminders and information about the importance and benefits of influenza vaccination, but resulted in only 28% of staff obtaining vaccination. 18 Similarly, in a tertiary Australian hospital in which an influenza vaccination promotion program had been in place since 2001, only 24% of staff reported being fully vaccinated despite 96% of staff indicating that they were willing to update their vaccination status. 17 In the United States, surveyed health care institutions have reported staff influenza vaccination rates ranging from 15% to 40%, despite national recommendations that health care workers receive vaccinations annually. 14 A study conducted in neonatal intensive care units in the United States found that influenza immunization compliance rates among staff ranged between 15% and 20% and that 76% of staff continued to care for patients despite reporting flu-like symptoms. 20 In the United Kingdom, less than 25% of health care workers are vaccinated against influenza each year despite being aware of the potential benefits of vaccination. 16 Many reasons for this low level of acceptance have been proposed; however, it seems most likely that continued resistance to accepting vaccination is largely because of attitudinal barriers. 21 Most health care workers believe that they are healthy and thus will derive no benefit from vaccination or that the risk of adverse events following immunization outweighs the benefits. Alternatively, they are simply unaware of the recommendations for annual influenza immunization. 20 It is possible that some health care workers may be conscientious objectors to vaccination; however, active refusals are unlikely to be a significant contributor to the low levels of vaccination among health care workers. Health care workers vary considerably in their health care knowledge, educational level, primary work environment, race, and culture. These factors affect the use of vaccination. For example, health care workers 50 years and older, of higher socioeconomic status, and with greater duration of employment at the same institution are more likely to accept vaccination than are those of lower socioeconomic status and shorter duration of employment, suggesting they are more familiar with influenza vaccination recommendations or possible risks and benefits to health care workers and patients. 22 To be effective, interventions to raise immunization rates need to identify specific barriers and concerns expressed by health care workers about influenza immunization and then target themthrough the implementation of policies, education programs, and improved access to vaccination. 14 Programs that actively target previously identified barriers have had a greater impact than have generic programs on staff vaccination rates. Increases in acceptance rates and reduced staff illness and absenteeism have been achieved by improving access to vaccination with a mobile unit, addressing common misconceptions through staff education, making vaccination free of charge, and offering small incentives to staff members who participated in the program. 13 , 23 Targeting previously identified barriers resulted in increases in vaccination rates from 42% to 77% over a period of three years in one setting and from 4.9% to 50.9% in another. 13 , 16 A US program that combined free vaccination with an educational component increased influenza vaccination coverage rates from 5% to 44% in one year. 24 These rates, however, remain significantly below the 83% to 94% levels required to achieve herd immunity. Despite considerable evidence that the vaccination of health care workers benefits workers, their patients, their families, and their institutions, few health care professionals take advantage of vaccination programs unless these programs are actively promoted or required as a condition of employment. Even when programs are actively promoted, the increases in vaccination rates generally remain below levels required to achieve herd immunity and, therefore, are unlikely to secure the potential benefits from high rates of vaccination.
