COVID-19 Is Not the Flu: Four Graphs from Four Countries

Abstract

Background: COVID-19 has caused a global public health emergency. In the absence of an effective vaccine, governments have implemented a series of behaviour-based prevention policies including physical distancing and preventive hygiene measures. These strategies are likely to impact the spread of other contagious respiratory illnesses, such as seasonal influenza. Our aim was to explore how the 2019-2020 influenza tracked with the COVID-19 pandemic and its mitigation methods. A secondary aim was to explore claims that the impact of COVID-19 is no different to influenza. Methods: We linked the WHO flu database (FluNet: containing influenza virological surveillance data) and COVID-19 confirmed cases (Johns Hopkins Coronavirus Resources Center) for four countries across the northern (Canada, United States) and southern hemispheres (Australia, Brazil) for the period 2016-2020. The datasets were merged and graphical presentations of the longitudinal data were provided. Findings: There was a notable reduction in influenza cases for the 2019-2020 season. Northern hemisphere countries experienced a quicker ending to the early year seasonal influenza cases (shortened by 4-7 weeks). Countries from the southern hemisphere experienced drastically low levels of seasonal influenza, with consistent trends that were approaching zero cases after the introduction of COVID-19 mitigation measures. Interpretation: COVID-19 mitigation measures are likely driving a marked decrease in influenza, including little to no 2020 influenza activity in the southern hemisphere. In spite of this reduction in influenza, there was still community spread of COVID-19, highlighting the contagiousness of SARS-CoV-2 compared to influenza. These results, together with the higher mortality rate from SARS-CoV-2 compared to influenza, provide clear evidence that the impact of COVID-19 is far greater than influenza. Another key consequence of these findings is the importance to instigate widespread influenza vaccination programmes to avoid a concomitant COVID-19 wave and influenza surge.Funding Statement: Funding for this project has come from a Canadian Institutes of Health Research-Strategy for Patient Oriented Research Mentoring Chair (SMC-151518, PI: Dr. Simon L. Bacon), a Fonds de Recherche du Québec: Santé Chair (251618, PI: Dr. Simon L. Bacon), Fonds de Recherche du Québec: Santé Senior Research Award (34757, PI: Dr. Kim L Lavoie), and a Canadian Institutes of Health Research COVID-19 grant (MS3‐ 173099, PI: Simon L. Bacon).Declaration of Interests: Dr. Bacon has received consultancy fees from Merck for the development of behavior change continuing education modules, speaker fees from Novartis and Janssen, and has served on advisory boards for Bayer, Sanofi, and Sojecci Inc none of which are related to the current article. Dr Lavoie has served on the advisory board for Schering-Plough, Takeda, AbbVie, Almirall, Janssen, GSK, Boehringer Ingelheim (BI), and Sojecci Inc, and received sponsorship for investigator-generated research grants from GlaxoSmithKline (GSK) and AbbVie, speaker fees from GSK, Astra-Zeneca, Astellas, Novartis, Takeda, AbbVie, Merck, Boehringer Ingelheim, Bayer, Pfizer and Air Liquide, and support for educational materials from Merck, none of which are related to the current article. Dr. Stojanovic and Mr. Gosselin-Boucher have nothing to declare.