There has been a good deal of recent media attention regarding what some see as a medical and ethical imperative that health-care workers be vaccinated against influenza. This view stems from two conclusions: vaccinating health-care workers protects patients from influenza-related harm, and current strategies have not been successful in achieving high vaccination rates.

Some Canadian jurisdictions want to see vaccination made mandatory while others want to mandate that unvaccinated workers wear a mask while at work throughout the influenza season.

Unfortunately, this issue is not as black and white as it has been portrayed: the evidence supporting influenza vaccination is not definitive and a lack of evidence and practical concerns make mandated masking a dubious policy.

More than 200 viruses can cause “influenza-like illness” and influenza is typically responsible for only 10 to 15 per cent of such illness each season. The majority of people who say they have “the flu” will not have influenza. Influenza vaccination does not protect against illness due to these other viruses. Some of these, such as respiratory syncytial virus, are being increasingly recognized as a dangerous pathogen affecting the elderly.

How well does the influenza vaccine work? On average, it is about 60-per-cent effective in protecting against influenza, although in some years, it is far less effective. Protection wanes as the influenza season wears on and by springtime its protective effect can be negligible. Some years the Centers for Disease Control and Prevention have recommended the use of prophylactic medications during outbreaks in vaccinated people because we cannot trust that the vaccine properly protects them. A renowned research group concluded last year that the public health community has been guilty of over-estimating vaccine effectiveness in order to encourage vaccination.

The evidence supporting vaccinating health care workers to protect patients is controversial. A recent meta-analysis that included the best studies showed that health-care worker vaccination does not protect patients from getting or dying from influenza but rather decreases deaths from any cause, and reduced influenza-like illness. The authors concluded that the best explanation for these confusing results was that the studies were biased. Unfortunately when conclusions such as these are published, they are often discounted when they should at least make us pause and think. Another recent meta-analysis found that vaccination had minimal impact on employee absenteeism.

Surprisingly, the debated evidence supporting vaccinating workers in long-term care has been used as justification to aggressively expand vaccination of workers to all health-care settings, including clinics where a patient might only spend a few minutes with a health-care worker.

So what about making unvaccinated health-care workers wear a mask at all times while at work? It is not clear how well wearing a mask while healthy would prevent infection, as this has never been studied as a strategy to prevent influenza. Studies have shown that a mask continually can at best cause discomfort, and at worst hinder patient care by impeding communication and increasing provider errors. It could easily be seen to be a punitive measure. Given the limitations of the vaccine and the other causes of influenza-like illness, an enforced approach requiring workers to wear a mask if coming to work ill (whether or not they have been vaccinated) or better yet, just staying home, makes more intuitive sense.

People who decline influenza vaccination state a wide range of reasons, many of which we neither understand nor agree with; however these beliefs are a reality that public health has to deal with. If public health leaders downplay vaccine limitations while at the same time engaging in heavy-handed strategies to drive vaccination, they will only be emboldening anti-vaccinationist beliefs by providing more evidence that the medical establishment is untrustworthy.

A savvy public armed with ever-greater levels of medical knowledge is growing frustrated with the absolute pronouncements of modern medicine and will likely challenge them. What will more half-truths bring for the future?

We get the influenza vaccine every year and encourage others to do so. Despite its shortcomings, it is the only vaccine we have right now; however, we stop short at forcing individuals to be vaccinated against influenza, either through mandatory programs or pseudo-mandatory programs such as “vaccine or mask.” This grey issue has too many caveats to justify taking away an individual’s autonomy.

There are serious patient safety issues in our hospitals. It is time to stop focusing on heavy-handed policies based on questionable evidence and move forward to strategies that engage health-care workers in making patient safety a top priority.

Michael Gardam, Camille Lemieux and Susy Hota are medical doctors with the Toronto University Health Network’s infection prevention and control unit.