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Fighting Microbes

The controversy over mandatory flu shots for healthcare workers has reared its head in British Columbia after an arbitrator upheld a policy that requires healthcare workers in the province either to get vaccinated or to mask up at all times...


The controversy over mandatory flu shots for healthcare workers has reared its head in British Columbia after an arbitrator upheld a policy that requires healthcare workers in the province either to get vaccinated or to mask up at all times during the flu season, which typically runs from November to April.

The decision by Queen’s Counsel Robert Diebolt, delivered on October 23, 2013, stems from a grievance filed by the Health Science Professionals Bargaining Association about the provincial Influenza Control Program Policy. The arbitrator dismissed the grievance by finding the policy a lawful exercise of the employers’ management rights. 

Val Avery, president of the Health Sciences Association, which challenged the policy on behalf of its 16,000 health science professionals, says she is “disappointed” with the ruling, but notes that the decision does address some privacy concerns the union had with the policy. The arbitrator has determined that “it was an abuse of the privacy rights of healthcare workers” to circulate the immunization status reports of employees at the workplace, as was done in 2012.

The original policy also required healthcare workers to report if their colleagues were not complying with the policy, which could create an unnecessary atmosphere of suspicion and accusation in the workplace. That requirement has also been removed.

The grievance underscores the fact that protecting healthcare workers from influenza involves more than just fighting microbes. On the research front, studies offer conflicting evidence on the effectiveness of flu vaccines.

In 2009, the British Columbia Centre for Disease Control (BCCDC) in Vancouver reported the results of four observational studies, which found that prior vaccination with the 2008-2009 trivalent inactivated influenza (TIV) vaccine was associated with an increased risk of pH1N1 illness during the spring and summer of 2009. However, the study acknowledged that the finding was not conclusive, as the people who had been vaccinated might have shared another unknown characteristic responsible for increasing their risk of developing pH1N1 illness.

Another study, Efficacy and Effectiveness of Influenza Vaccines: A Systematic Review and Meta-Analysis, published in October of 2011, found that while flu vaccines provide moderate protection against virologically confirmed influenza, such protection is greatly reduced or absent in some seasons.

“It is about 60 per cent effective every year in protecting people from influenza,” says Dr. Bonnie Henry, medical director of communicable disease control with the BCCDC. The effectiveness of flu vaccines varies depending on the season, how well the vaccine is matched to the circulating strains and an individual’s ability to mount a good immune response. As the vaccine works best in healthy people — a category that most healthcare workers fit into — Dr. Henry encourages healthcare workers to take the flu shot.

“Because it is not 100 per cent effective, it’s really important that all of us help keep the susceptible population down,” she says, noting that the measures in the policy adopted by British Columbia help to keep influenza out of healthcare facilities, particularly in long-term care homes where outbreaks occur.

“Every day during flu season, nurses see the very real impact that the flu can have — not just on children and the elderly, but on otherwise perfectly healthy adults,” Julie Fraser, president of the Association of Registered Nurses of British Columbia in Vancouver, said in a statement on November 7 in support of the province’s move.

More Questions

Dr. Michael Gardam, director of infection protection and control at the University Health Network in Toronto, takes the flu shot every year. He recommends healthcare workers do the same, but does not think that it should be made mandatory. He remembers 2012 as a particularly bad influenza season, during which healthcare workers who had received the flu shot were getting sick and had to take antivirals.

“Of all the sort of routine vaccinations that we give people, the flu shot is probably the least effective of any of them. It’s unclear to me why we would be so aggressive with this vaccine to the point of making it mandatory when it really doesn’t work very well,” Dr. Gardam contends.

He adds that one of the main problems with developing vaccines is the virus mutates all the time. “It is always a bit of a moving target,” Dr. Gardam says. “Sometimes, a flu shot does not work very well, because the strains it was made against are not the strains that are actually circulating.”

He also questions how much protection is offered by wearing a mask, which he describes as “a theoretical measure at best”. He points to the growing debate in the occupational health and safety community that airborne-sized droplets are one of the key modes of flu transmission. “Those are not being filtered by these masks,” Dr. Gardam says, “unless you are wearing the respirator.”

A flu vaccine traditionally protects against three strains of viruses: two A strains and one B strain. “We are doing a pretty good job with the influenza A strains,” Dr. Henry says, but not with influenza B strains. “One of the things that is going to help us with that is a quadrivalent vaccine that contains both of the B strains. And that should be available in Canada starting next year.”

West to East

It is common knowledge that flu viruses are transmitted by airborne droplets from infected persons who cough, sneeze or talk, or through physical contact with a surface or object contaminated by the flu virus. But what is less well understood is the spatial pattern in which influenza spreads in Canada.

A study, led by DaiHai He while he was a postdoctoral researcher at McMaster University in Hamilton, Ontario was published in the Proceedings of the Royal Society B in August of 2013. It investigated the patterns of laboratory-confirmed influenza A across Canada from October of 1999 to August of 2012. A statistical analysis of the seasonal epidemics in this period established a spatio-temporal pattern indicating that influenza spreads from west to east across the country. Early emergence in the western provinces is correlated with low temperature and low humidity in the fall.

Transmission rates also appear to be influenced by contact and weather patterns. School closures, which have led to a significant reduction in flu transmission, suggest that it can be considered a measure to control the prevention of infectious diseases. “Overall, our study suggests that better understanding of the factors underlying patterns of spatio-temporal spread will be very useful for designing and prioritizing vaccination and other control efforts,” the study concludes.

The Centers for Disease Control and Prevention in Washington, D.C. says the elderly, residents in nursing homes, young children, pregnant women and people with certain health conditions such as asthma, diabetes or heart disease are at greater risk of serious complications if they contract the flu. Influenza seasons are unpredictable and its severity can vary widely from season to season. The influencing factors include what flu viruses are spreading, when and how much flu vaccine is available, how many people get vaccinated and how well the vaccine is matched to circulating flu viruses.

A series of laboratories around the world and in Canada monitors how the flu virus is changing — especially near the end of the season — and observes what is happening in the southern hemisphere, where the flu season occurs in a cycle opposite to the northern hemisphere’s. “That helps us predict what circulating strains are going to be in our community and that is how vacc
ines are developed,” Dr. Henry explains.

Every February, Dr. Gardam says an “intelligent guess” is made as to which strain is going to circulate. “Most of the time, it’s reasonably accurate.” However, mismatches do occur. Even if there is a good match, there is still a chance that the vaccine may not be as effective, “largely because the parts of the virus that the vaccine is made against just aren’t really great sites to make a vaccine.”

Adjuvanted vaccines, which contain pharmacological agents added to boost the body’s immune response to the vaccine, tend to induce superior immune effectiveness than unadjuvanted ones, although that varies from manufacturer to manufacturer and from season to season, notes Dr. Andrew Potter, chief executive officer of the Vaccine and Infectious Disease Organization with the University of Saskatchewan in Saskatoon.

“The data I have seen on retrospective views of events, such as the H1N1 scare, suggests that they are remarkably effective, although clearly not as effective as some other vaccines,” Dr. Potter says. “However, given the heterologous strains circulating, this is not especially surprising.”

Dr. Potter believes the needle-free flu shot, an intranasal product that can induce mucosal immunity available in some provinces, would encourage uptake. “I am a fan of getting rid of invasive forms of vaccine delivery,” he says. “I do believe that many people simply do not like getting a shot.”

On the Ground

Lynn Ronnebeck, a registered nurse and infection-control professional with the Lake of the Woods District Hospital in Kenora, Ontario, says she does not dread the flu season. “As an infection-control professional, I promote the flu shot.”

Ronnebeck cites an editorial by Dr. Ken Flegel, medical doctor and senior associate editor of the Canadian Medical Association Journal, published in the journal in October of 2012. The editorial refers to findings in four randomized trials, which show a five to 20 per cent reduction in overall seasonal mortality in residents of chronic care institutions where staff vaccination rates were 51 to 70 per cent. A cost-benefit analysis from a health-systems perspective also found that for every US$1,000 spent on vaccination of healthcare workers, US$1,600 was saved, notes the editorial, citing findings from Mandatory Influenza Immunization for Health Care Workers — an Ethical Discussion, published in 2007.

While Dr. Flegel acknowledges that compulsory vaccination may be regarded as ethically questionable, since it violates a person’s autonomy, he argues that in the case of influenza vaccination, the autonomy of healthcare workers conflicts with the best interests of patients.

“To justify compulsory vaccination, there must be an outbreak of serious illness; immunity levels must be low; the vaccine must be effective, safe and available; and vaccine uptake must be low. These conditions appear to be met for annual seasonal influenza,” Dr. Flegel writes.

Like British Columbia, Ontario’s London Health Sciences in London and Bluewater Health in Sarnia have made it mandatory for healthcare workers either to mask up or take the jab. “If you are working in healthcare, you are working with a vulnerable population with compromised immune status, multiple-system involvement and you can become a factor for the flu,” says Rhonda Seidman-Carlson, president of the Registered Nurses’ Association of Ontario in Toronto. “There are more people who die of the flu than who have any kind of reaction from the flu shot.”

Besides wearing a mask and getting the vaccination, other protective measures include washing hands regularly with soap and water or using alcohol-based hand sanitizer, and avoiding touching one’s face and nose. “The other really important thing is if you are sick, especially if you have a fever,” Dr. Henry advises, “stay home.”

Jean Lian is editor of OHS Canada.

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