Issue: July 2020
Source: Healio Interviews
Disclosures: Boey, Coleman, Hayney, Schaffner and Koppaka report no relevant financial disclosures. Whitley-Williams reports owning stock in Pfizer.
July 21, 2020
10 min read

Flu vaccination ‘a professional and ethical responsibility’ for all HCWs

Issue: July 2020
Source: Healio Interviews
Disclosures: Boey, Coleman, Hayney, Schaffner and Koppaka report no relevant financial disclosures. Whitley-Williams reports owning stock in Pfizer.
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As a resident, William Schaffner, MD, once showed up to work with influenza and was met by an incredulous look from his chief resident, who promptly sent him home.

As time passed, Schaffner learned just how important it is to protect himself, his coworkers and patients from influenza by getting vaccinated each year. Yet studies consistently show that many health care workers (HCWs) do not receive a seasonal influenza vaccine.

One way to increase influenza vaccination among health care workers is to directly address their concerns about the vaccine, said William Schaffner, MD.

Source: Vanderbilt University Medical Center

“It is both a professional and an ethical responsibility for all health care workers to be vaccinated against influenza, because it is a patient safety issue,” Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center and an Infectious Disease News Editorial Board Member, said in an interview. “We do not want to transmit a virus that we might carry to our patients. Vaccination is even more important this coming season because of COVID-19. We want to do as much as possible to keep ourselves healthy so we can take care of the patients who need us.”

Infectious Disease News spoke with Schaffner and other experts about the importance of influenza vaccination among HCWs and what a lack of vaccination could mean during the upcoming influenza season with COVID-19 circulating at the same time.

Low coverage

By preventing influenza or mitigating its effects, influenza vaccination lessens the burden on the health care system each year, explained Ram Koppaka, MD, PhD, associate director for adult immunization in the CDC’s Immunization Services Division.

“For example, during the 2017-2018 season” — one of the most severe influenza seasons in recent years — “vaccination prevented an estimated 6.2 million influenza illnesses, 3.2 million influenza-associated medical visits, 91,000 influenza-associated hospitalizations and 5,700 influenza-associated deaths,” Koppaka told Infectious Disease News.

Influenza vaccine effectiveness generally ranges between 40% and 60%, Koppaka noted. Preliminary results showed that the 2019-2020 vaccine was 39% effective, according to a presentation during the June meeting of the CDC’s Advisory Committee on Immunization Practices (ACIP). However, in addition to preventing tens of thousands of hospitalizations each year, influenza vaccination reduced the risk for being admitted to an ICU by 82% from 2012-2015.

Despite these benefits, not all HCWs are vaccinated annually. According to the CDC, influenza vaccination coverage among HCWs was 81.1% during the 2018-2019 influenza season, which was similar to the coverage reported during the previous four seasons (77.3% to 79%). CDC data showed that, during the 2018-2019 season, influenza vaccination was highest among physicians (96.7%), nurses (98.1%), pharmacists (91.5%) and nurse practitioners and physician assistants (91%), and lowest among other clinical health care personnel (85.8%), assistants and aides (72.5%) and nonclinical health care personnel (75.5%).

Ram Koppaka, MD, PhD
Ram Koppaka

Overall vaccination coverage was highest among HCWs in hospitals (95.2%) and those at facilities where vaccination is required (97.7%).

“Since HCWs may care for or live with people at high risk for influenza-related complications, it is especially important for them to get vaccinated annually,” Koppaka said.

A matter of patient safety

Over the past 8 years, large institutions have increasingly mandated that all staff, including doctors who only admit patients, be vaccinated against influenza, Schaffner said.

A study published in JAMA in 2018 reported that the percentage of U.S. hospitals requiring annual influenza vaccination for HCWs increased from 37.1% in 2013 to 61.4% in 2017 (difference, 24.3%; 95% CI, 18.4%-30.2%). The increase was driven by non-Veterans Affairs hospitals, almost 70% of which had mandatory vaccination policies, researchers reported.

Studies have underlined the importance of mandatory vaccination by assessing how many HCWs continue to report to work while sick. One such study retrospectively enrolled HCWs at nine Canadian hospitals that conducted active surveillance for acute respiratory illness during the 2010-2011 through 2013-2014 influenza seasons.

Brenda L. Coleman, PhD, a clinical scientist at Mount Sinai Hospital in Toronto, told Infectious Disease News previously that assessing this information will “help infection control and occupational health teams determine whether changes need to be made to policies to reduce the risk of spreading respiratory infections among staff and patients.”

Overall, Coleman and colleagues found that 94.6% of the HCWs who reported having a respiratory illness worked at least 1 day during that illness. Additionally, 67% of HCWs said they worked while symptomatic because they believed their symptoms were mild and they felt well enough to work.

However, research has shown that even HCWs who are not exhibiting symptoms of influenza can still transmit the virus to patients. A study presented at the 2019 European Congress of Clinical Microbiology & Infectious Diseases found that a “significant proportion” of HCWs shed influenza virus before the onset of symptoms.

The study, which tracked influenza transmission at a hospital in Switzerland, detected several influenza transmission clusters that went undetected by routine surveillance and seven clusters of potential transmission among HCWs, including one that appeared to include transmission from an asymptomatic HCW to a patient.

The researchers examined asymptomatic transmission by collecting nasal swabs daily to track infections and contacts. After testing the swabs, they found that 16.9% of influenza-positive swabs from HCWs and 8.1% of influenza-positive swabs from inpatients were collected on days that those who were tested did not report symptoms. Additionally, 12.5% of HCWs and 10.5% of inpatients who tested positive remained asymptomatic for the duration of their infection. Two (13%) of the HCWs and none of the symptomatic inpatients had a positive influenza test before symptoms developed.


Another study showed that more than 50% of health care trainees work despite having influenza symptoms, citing “not wanting to burden colleagues” with heavier workloads as their reason for working through symptoms and sickness.

Still, it is not mandatory for HCWs at every facility in the United States to receive the influenza vaccine.

“Mandates come in a variety of flavors,” Schaffner said. “The harshest ones will actually discharge workers, including nurses, who are not vaccinated. At Vanderbilt, we don’t do that. We have a structure so that if a health care worker does not wish to be vaccinated, they can apply for an exemption and they have to give a reason.”

According to Schaffner, these reasons are then reviewed by a committee and assessed for approval, although he said there are very few medical reasons that would excuse an HCW from being vaccinated.

“Ninety-nine times out of 100, when it’s explained that they don’t qualify for one of those reasons, they wind up being vaccinated,” he said. “With our careful education and review system, we get over 96% or 97% of our folks vaccinated.”

A study published in InfectionControl & Hospital Epidemiology examining medical waivers for influenza vaccination at the University of Wisconsin Hospitals and Clinics showed that few HCWs who requested them had a true medical contraindication. The health system changed its personal waiver policies for the 2018-2019 influenza season.

“We realized that as recommendations for influenza vaccine have evolved over the years, we should reexamine the medical waiver policy and ask relevant individuals to resubmit the waiver, get the vaccine or submit a personal waiver from those whose previously submitted medical waivers were no longer in compliance with current influenza vaccine recommendations,” Mary S. Hayney, PharmD, MPH, professor of pharmacy practice at the University of Wisconsin School of Pharmacy, told Infectious Disease News.

Among 131 employees with a prior medical waiver on file, Employee Health Services approved 35 medical exemptions (27%) based on updated ACIP guidelines. Of the remaining 96 employees, 14 were no longer employed by University of Wisconsin Hospitals and Clinics and 82 were required to act to stay in compliance with the seasonal influenza vaccination requirement.

Mary S. Hayney, PharmD, MPH
Mary S. Hayney

Hayney and colleagues found that only 19 of those 82 employees (23.1%) received the 2019-2020 influenza vaccine. A greater proportion of employees with previous severe allergic reactions to egg products submitted personal waivers in 2019-2020 compared with both those with common side effects from the influenza vaccine, such as influenza-like symptoms, injection site reaction or shoulder injury related to vaccine administration (OR = 1.14; 95% CI, 0.34-3.87), and employees with reactions not commonly associated with the vaccine, including Guillain-Barré syndrome and exacerbation of an inflammatory condition (OR = 1.62; 95% CI, 0.51-5.12).


“Although it is important to keep health care system medical waiver policies current, a multipronged approach is needed to keep HCW influenza immunization rates very high,” Hayney said.

Overcoming barriers, fears

One way to ensure increased vaccination among HCWs is to directly address their relevant concerns, according to Schaffner. He said the reasons HCWs are not vaccinated have been studied extensively, primarily through surveys. They include cost and availability, though Schaffner noted that the vaccine is almost always free and “virtually all medical centers have learned to do it conveniently.”

“You’d be surprised,” he said. “Some HCWs just don’t like to get stuck with needles, so they don’t get vaccinated. It’s true.”

Fast Facts

Additionally, some HCWs do not think the vaccine works, whereas others are concerned about side effects, Schaffner said. A small survey at one St. Louis hospital showed that around one-quarter of respondents had doubts about the influenza vaccine’s safety and effectiveness.

“In other words, they’re human beings, just like the rest of us,” he said, “but we think all health care workers should be vaccinated against influenza annually. It’s not a perfect vaccine — we can talk about that until the cows come home — but it’s the best we have. As Voltaire, the old French philosopher, admonished us, ‘Waiting for perfection is the great enemy of the current good.’”

In terms of overcoming these barriers, leadership, education and group efforts are key to improving vaccination uptake, according to Schaffner.

“People have to understand that this is about patient safety, as well as wanting to keep health care workers as healthy as possible so that they can care for patients during the influenza season,” he said.

A study presented at the National Foundation for Infectious Diseases’ Annual Conference on Vaccinology Research in 2019 demonstrated that HCWs can be convinced to get vaccinated without making it mandatory through the use of promotional materials such as educational brochures and instruction manuals that encourage vaccination. The use of such materials during a 2017 vaccination campaign in Belgium led to an increase in vaccination, from 58% at baseline to 71.5% at follow-up.

“If health care facilities are willing to make an effort and produce a good campaign, they can increase their vaccination coverage, but they have to invest time and financial resources to make a well-prepared campaign,” Lise Boey, MSc, a PhD student at Leuven University Vaccinology Center in Belgium, told Infectious Disease News at the time of the presentation.


If facilities want to see more staff vaccinated, they will likely need to implement some rules or mandates, according to Schaffner.

“Everyone who works at the facility — whether that’s a dietitian, a secretary, the head of the medical staff or a janitor — gets vaccinated for our patients’ benefits,” he said. “When you put that mandate in, you get pushback the first year and a little pushback the second year. By the time the third year rolls around, it’s routine. It’s humdrum. Everybody’s rolling up their sleeve.”

“If every other hospital in town does it, we’re all doing this together,” he added.

Despite some pushback, research has shown that mandatory vaccination policies do work. One study published in Infection Control & Hospital Epidemiology found that mandatory vaccination policies at three sites resulted in an approximately 30% increase in vaccination rates and reduced the occurrence and duration of symptomatic absences. This led to an estimated 5.9% decrease in HCWs claiming any sick days at sites with mandatory vaccination compared with sites where vaccination was not mandatory (95% CI, –12.5 to –1.4; P = .02).

An Infectious Diseases Society of America spokesperson told Infectious Disease News that the organization remains committed to doing all it can to maximize immunization rates and is working on “a comprehensive set of policy recommendations to expand vaccine uptake” among HCWs. The IDSA will also work on additional influenza-specific efforts as the 2020-2021 influenza season approaches, the spokesperson said.

Vaccination ‘even more important this year’

As the 2020-2021 influenza season nears, Schaffner emphasized the effect that COVID-19 may have on health care should the two viruses peak simultaneously.

A study in Clinical Infectious Diseases that assessed seasonal influenza and coronaviruses over seven seasons found that influenza vaccination did not have an effect on coronaviruses or other noninfluenza respiratory viruses, contrary to a study that suggested it might increase the risk for illness due to coronaviruses. According to Schaffner, it is important that HCWs prepare for COVID-19 and infuenza to be circulating widely at the same time by getting vaccinated to decrease the likelihood of missing work because of influenza and putting additional strain on fellow HCWs.

“Vaccination is even more important this year,” Schaffner said. “The influenza vaccine does not directly have anything to do with COVID-19. But we need as many HCWs on the job as possible. We don’t want them home with influenza while we’re dealing with both influenza and COVID-19.”

Koppaka agreed.

“Health care providers have been on the front lines of the COVID-19 response and seen the toll this pandemic is taking on the system,” he said.


Patricia N. Whitley-Williams, MD, president of the NFID and professor of pediatrics and chief of the division of allergy, immunology and infectious diseases in the department of pediatrics at Rutgers Robert Wood Johnson Medical School, said influenza vaccination is vital to protect HCWs and is “even more urgent” in the context of COVID-19.

“With a COVID-19 vaccine at least a year away, influenza vaccination can help protect HCWs, keep them on the job and prevent additional strain on an already overburdened health care system,” she told Infectious Disease News. “Now is the time to overcome barriers around HCW immunization. Getting an annual influenza vaccine is an essential responsibility of all HCWs to reduce the likelihood of becoming ill ourselves or spreading influenza to our patients and in our communities.”

Patricia N. Whitley-Williams, MD
Patricia N. Whitley-Williams

During the 2019-2020 influenza season, influenza and influenza-related complications caused up to 56 million illnesses, 740,000 hospitalizations and at least 24,000 deaths in the United States, Whitley-Williams explained. The 2020-2021 season could be “even more severe.”

“We could face a double onslaught of COVID-19 and influenza circulating simultaneously,” she said. “Health care facilities and personnel could be stretched to their limits. If all HCWs are vaccinated against influenza, we can help reduce the burden.”

According to Schaffner, the “short answer” to the question of whether all HCWs should be vaccinated against influenza is “yes, in all caps, with an exclamation mark or two.”

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