Healthcare Worker Influenza Immunization: Mandates, Benefits, Consequences

October 1, 2013 Karie Youngdahl

Asian Flu Vaccine, 1958As influenza season approaches, many hospitals and health systems are asking their staff to take the influenza vaccine. Some merely suggest or recommend it, but others mandate it. Consequences for noncompliance range from having to wear a mask during patient care encounters during the influenza season to termination of employment

The reasoning behind requiring health care worker (HCW) influenza immunization relates to possible effects on outcomes related to the hospital environment and patient care, such as

  • Preventing spread of influenza to patients
  • Worker absenteeism during busy influenza season
  • Modeling preventive health behaviors to patients

The Advisory Committee on Immunization Practices has recommended HCW flu vaccination since 1984. Though the rates of vaccination have been rising, only about 66% of HCWs receive the seasonal vaccine (CDC, 2012). In response, some hospitals and health systems have instituted universal mandatory influenza vaccination, whereas many others have made additional efforts to encourage staff to take the vaccine.

In 2009, Children’s Hospital of Philadelphia was an early adopter in the Philadelphia area of a mandatory influenza vaccination policy. It applies to all hospital staff who work in buildings where patients receive clinical care, including housekeeping staff, kitchen staff, and maintenance staff as well as HCWs. Dismissal is the consequence for not accepting vaccination in the absence of a valid medical (or, rarely, religious) exemption from the requirement. In the first season of implementation, CHOP terminated 9 workers who refused vaccination. The vaccine acceptance rate went from about 90% in previous years to virtually 100% of its 9,500-person targeted staff.

Susan Coffin, MD, MPH, who helped devise, implement, and monitor CHOP’s policy, has written widely about those experiences, often including information about influenza spread in the hospital setting. In one report, she noted that infected individuals may shed influenza virus up to 24 hours before symptoms begin (Coffin, 2010). Also, viral shed is possible by infected individuals who never develop influenza symptoms. Coffin pointed me to a BMJ study reporting that of 120 HCWs who had serological evidence of recent influenza infection, 59% did not recall having flu, and 28% recalled having no respiratory infections whatsoever (Elder et al., 1996). Presumably, those workers might have been able to infect their patients while assuming they didn’t have influenza.

In terms of influenza in hospitalized patients, Coffin described 56 identified cases of hospital-acquired influenza at CHOP in the years 2000-2004. Of those cases, influenza complications included 2 deaths, 3 cases of respiratory failure, 12 cases of bacterial pneumonia, and 1 case of bacteremia (Coffin, 2010). It’s impossible to say whether, in retrospect, a mandatory HCW vaccination policy would have prevented any of those cases or complications. However, the CHOP policy is aimed at trying to avert those kinds of outcomes.

Indeed, it’s difficult to get a convincing picture of the magnitude of the effect of HCW immunization on hospital-acquired influenza – data on the effects of influenza immunization of HCWs can point in all directions. For example, a recent Cochrane Review found no benefit for older patients in long-term care facilities when HCWs are vaccinated against flu (Thomas et al., 2013). Nevertheless, most expert bodies on infectious diseases, hospital infection control, and immunization come down on the benefits side of the risk/benefits equation for immunization of HCWs, particularly in relation to protecting the health of patients. As Coffin and others state in a letter to BMJ, “Healthy adults mount better immune responses to flu vaccine than do vulnerable patients, so vaccinating workers may provide more effective protection than vaccinating patients themselves” (Behrman et al., 2011). 

Other local health systems are adopting universal immunization policies in CHOP’s wake. Main Line Health System implemented its mandatory influenza immunization policy in 2010. Workers who do not have a valid medical or religious exemption and still decline the vaccine lose their jobs. As of September 4, 2013, Temple University Health System has implemented a universal influenza vaccination policy for all healthcare workers – which includes all employees, residents, students, instructors, members of medical staffs, volunteers, and other business personnel at any TUHS location, including non-medical administrative buildings. Those who refuse must wear a surgical mask during the flu season when within six feet of a patient or healthcare provider. 

How effective are mandatory immunization policies on increasing vaccination uptake in personnel? A recent study in Infection Control & Hospital Epidemiology found that consequences such as termination and masking requirements were associated with increased immunization rates (Zimmerman et al., 2013). As stated previously, CHOP now has achieved 100% vaccination of non-exempt workers. And Coffin noted that an unexpected benefit of the universal policy is a reduction in time and effort spent reaching the last few workers who resist vaccination. Those resources are freed up and can be used for other needs.

On Thursday, our advisor Thomas Fekete, MD, will write about the topic of HCW influenza vaccination and the evidence and policies that underlie mandatory policies.

Sources and More Information

Behrman AJ, Caplan AL, Coffin SE, Fishman N. Doctors choosing not to be vaccinated is choosing to do harm. BMJ. 2011 Nov 8;343:d7198. Doi: 10.1136/bmj.d7198.

Centers for Disease Control and Prevention. Influenza vaccination coverage among health-care personnel -- 2011-12 season, United States. MMWR. 61(38);753-757

Centers for Disease Control and Prevention. State immunization laws for workers and patients (current as of June 2013). Online tool found at

Coffin S. Carrots and sticks: Influenza vaccination of healthcare workers. June 2010.

Elder AG, O’Donnell B, McCruden EAB, Symington IS, Carman WF. Incidence and recall of influenza in a cohort of Glasgow healthcare workers during the 1993-4 epidemic: results of serum testing and questionnaire. BMJ. 1996:313:1241-2.

Miller BL, Ahmed FA, Lindley MC, Wortley PM. Institutional Requirements for Influenza Vaccination of Healthcare Personnel: Results From a Nationally Representative Survey of Acute Care Hospitals—United States, 2011. CID. 2013;11:1051-59.

National Foundation for Infectious Diseases. Call to action. Improving low influenza vaccination rates among health care personnel requires comprehensive approach, institutional commitment.

Thomas RE, Jefferson T, Lasserson TJ. Influenza vaccination for healthcare workers who care for people aged 60 or older living in long-term care institutions. Cochrane Database of Systematic Reviews. 2013. DoiL10.1002/14651858.CD005187.pub4

Universal flu immunization programs for health care personnel. Best practice series. The Hospital and Healthsystem Association of Pennsylvania. Winter 2013.

Zimmerman RK, Lin CJ, Raymund M, Bialor J, Sweeney PM, Nowalk MP. Hospital policies, state laws, and healthcare worker influenza vaccination rates. ICHE. 34;8:854-7.

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