Health services across the Northern Hemisphere are once again bracing for what many in the media like to call the “winter crisis” – an acute, annual imbalance when healthcare demand exceeds supply.[1][2][3]As usual, health officials warn us of the threat of hospitals being over capacity, and the media dutifully feeds us dramatic stories of people lying on beds in hallways, the floor, or any other available space.
The source of the crisis? “Flu” season.[4]
Where I live, these winter surges tend to occur on either side of Christmas (see Figure 1). However, the pattern is not as predictable as the headlines. Some years can have very little activity (2011-12 and 2023-24); others arrive early and disappear quickly (2009-10); and sometimes, they stubbornly hang on into the spring (2024-25).
Figure 1 – Weekly influenza case counts (i.e., test positive) by influenza season in the Canadian province of Alberta (2009-2026).[5]Data from season 2020-21 have been omitted because of no activity in this season. Vertical dashed line represents the week of Christmas; and smooth solid black line represents the average number of cases across all seasons displayed.
Public dispatches from health officials and their allied spokespeople roll out in sync: the flu is not just a bad cold. It can result in severe illness, hospitalization, and sometimes, even death.
The solution to preventing the crisis? Get a flu shot. Get it early. Encourage your family, friends, colleagues, and community to do the same.[6]
Those who choose to get vaccinated are championed as model citizens: compassionate, kind, and caring; those giving the vaccines are “knights [wielding] syringes like swords – using their powerful influenza vaccines to vanquish the flu dragon” (Figure 2).
Figure 2 – The “community of knights” vanquishing the flu dragon. Image is taken from Alberta Health Services News and Advisory website in 2020.
For many spokespeople – including physicians, public health and government officials – they need only claim that influenza vaccines save lives, and it is assumed that there is solid research behind it.
However, closer examination of influenza vaccine policies shows that although proponents employ the rhetoric of science, the studies underlying many policies are often of low quality, and do not substantiate officials’ claims. The vaccine might be less beneficial and less safe than has been claimed, and the threat of influenza appears overstated.
If this is starting to sound a lot like the “measles situation” – or nearly any other vaccine-targeted disease – you are not imagining it.
This is not to say influenza vaccines lack proven benefits. Three large, long-running Cochrane Reviews[7][8][9]– careful, systematic summaries of all relevant research on specific medical questions – have demonstrated that vaccinated healthy adults, healthy children, and older adults probably experience about half as many symptomatic cases of influenza than those who are not vaccinated. Depending on the match between vaccine and circulating stains, vaccinating 67 healthy adults (on average), prevents one less symptomatic case of influenza; in children over the age of two years, that number improves to about five, though the evidence carries significant uncertainty.
However, this reality seems difficult for health commentators to grasp. Many appear eager to take the most impressive-sounding number and apply it to all outcomes for all people. But the same Cochrane Reviews also conclude that the evidence is weak and uncertain when it comes to more serious outcomes, such as hospitalization or death. The intuitive argument – fewer cases should produce fewer complications – is tempting but not well supported by data.
Part of the reason lies in who gets studied. Most of the published trials are conducted in healthy adults – those with the least to gain from vaccination – that measured antibody production in the blood as a surrogate outcome of “benefit” – which, as an immune response, has little field value as a measure of protection.
Systematic reviews outside the Cochrane Collaboration provide little evidence that influenza vaccines prevent transmission or reduce the number of sick days from work.[10]One follow-up study of a randomized trial even showed that recipients of the trivalent influenza vaccine had a four-fold increase in non-influenza acute respiratory infections shortly after peak flu activity.[11]
Another subtle – but influential – aspect surrounding annual influenza messaging is the claim that “flu” and “influenza” are the same. They are not.
In an article discussing the marketing of influenza vaccines, Peter Doshi[12]highlights that:
“[The] general lack of awareness of the difference [is] the primary reason few people realize that even [a 100% effective] influenza vaccine … can only deal with [an average 16%] of the ‘flu’ problem because most ‘flu’ appears to have nothing to do with influenza.”
In other words, Doshi concludes, “all influenza is ‘flu’, but only one in six ‘flus’ might be influenza. [And] it’s no wonder so many people feel that ‘flu shots’ do not work – for most flus, they can’t.”
This distinction is important.
Because “flu season” is really a collection of influenza-like illnesses – most of which cannot be influenced by influenza vaccines – the annual claim that “flu shots” will relieve system strain is, at best, false advertising.
So where does this leave individuals? Get the shot. Don’t get the shot. The choice is yours.
Deciding whether to get vaccinated ultimately comes down to assessing personal risk – age, medical condition, risk of exposure, and comfort with uncertainty. For some people, an influenza vaccine may still make sense. The problem is not the vaccines themselves; it is the oversized promises attached to them and the way existing knowledge gaps are contorted into black-and-white messaging.
Some in healthcare have already been using the winter crisis as a political football.[13]Others will continue trying to balance the data as the season unfolds. And while this year’s “flu season” will eventually pass, one thing appears certain; public health officials, bureaucrats, and media commentators will be back next year, once again warning of crisis and offering familiar solutions – whether, or not, the underlying evidence has changed meaningfully.
References & Notes
[1] CBC, If Australia is any indication, Alberta could be in for a tough flu season
[2] The Guardian, Surge in flu cases risks overwhelming hospitals in England, says NHS chief
[3] Chief Healthcare Executive, Hospitals wrestling with worst flu season in years
[4] Well… At least for the past 2 decades that’s been the case. In 2022, warnings of a “tripledemic” – the simultaneous occurrence of increased cases of influenza, respiratory syncytial virus (RSV), and COVID-19 – gained popularity and served as an escalated “wake-up call” of how serious winter can be. See the article by Apoorva Mandavilli in the New York Times: A ‘Tripledemic’? Flu, R.S.V. and Covid May Collide This Winter, Experts Say
[5] Alberta Health, Respiratory Virus Dashboard
[6] Alberta Health Services, Fight the Flu Season
[7] Demicheli V, et al, Cochrane Database of Systematic Reviews 2018; Issue 2, Vaccines for preventing influenza in healthy adults, Last Accessed: 02 November 2025
[8] Jefferson T, et al. Cochrane Database of Systematic Reviews 2018, Issue 2, Vaccines for preventing influenza in healthy children, Last Accessed: 02 November 2025
[9] Demicheli V, et al. Cochrane Database of Systematic Reviews 2018, Issue 2, Vaccines for preventing influenza in the elderly, Last Accessed: 02 November 2025
[10] Osterholm MT, et al. Lancet Infectious Diseases 2012; 12(1): 36-44, Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis
[11] Cowling B, et al. Clinical Infectious Diseases 2012; 54(12): 1778–83. Increased Risk of Noninfluenza Respiratory Virus Infections Associated With Receipt of Inactivated Influenza Vaccine
[12] Doshi P. BMJ 2013; 346: f3037, Influenza: marketing vaccine by marketing disease
[13] The Tyee, ‘Pure Chaos’: Warnings of an Alberta Health-Care Crisis
