Editorial: A Decline in Influenza During the COVID-19 Pandemic and the Emergence of Potential Epidemic and Pandemic Influenza Viruses

Abstract

There have been five viral pandemics in the past century, four were due to influenza, and the ongoing COVID-19 pandemic is due to SARS-CoV-2 infection. During the COVID-19 pandemic, there has been a 99% global reduction in the diagnosis of influenza. Also, from 2020, global mortality rates from influenza fell to record levels during the influenza seasons in the southern and northern hemispheres. However, as social restrictions become lifted and the winter season begins in the northern hemisphere, it is expected that influenza will re-emerge. The World Health Organization (WHO) FluNet surveillance platform provides global surveillance data on influenza, and the US Centers for Disease Control and Prevention (CDC) records national weekly infection rates. Both surveillance programs have identified zoonotic avian and swine influenza variants in humans. The WHO Pandemic Influenza Preparedness (PIP) Framework requires WHO Member States to share data on cases of emerging influenza viruses with pandemic potential in a regular and timely way. The WHO PIP Framework organizes the Global Influenza Surveillance and Response System (GISRS), a global network of public health laboratories developing candidate virus vaccines. This Editorial aims to present the reasons for concern regarding the emergence of pandemic influenza viruses driven by the social and public health responses to the COVID-19 pandemic and highlights the importance of global influenza surveillance at this time.

The Influence of COVID-19 on Influenza and Respiratory Syncytial Virus Activities

“…Several studies conducted during the early months of the pandemic demonstrated an overall decline in non-COVID-19 respiratory viral infections [ 24 , 25 ]. Reports from other countries, including China, Australia, and France, also cited diminished flu cases since the pandemic was declared [ 26 , 27 ].…”

“…Although nonpharmaceutical interventions helped to reduce non-COVID-19 respiratory viral diseases, we should not shift our focus from traditional respiratory viruses to COVID-19 only. The upsurge of RSV perhaps was not an isolated phenomenon and should be considered as an eye-opener as other respiratory viruses can have a similar comeback [ 25 ]. Some experts have even warned against the future resurgence of flu [ 44 ].…”

Reduced spread of influenza and other respiratory viral infections during the COVID-19 pandemic in southern Puerto Rico

“…These declines have been broadly attributed to population-wide preventative measures, including handwashing, face mask wearing and social distancing. Previous to COVID-19, significant events that restrict human mobility, such as major winter storms, have shown reductions in transmission of influenza as well as other respiratory infections [ 36 ] Preventative measures such as mask wearing and social distancing have become and remain important mitigation measures for reducing transmission of SARS-CoV-2 [ 37 ], and growing evidence suggests these may have a greater impact on reducing the spread of influenza [ 38 , 39 ], RSV, AdV and other respiratory infections even in warmer climates.…”

Editorial: Global Surveillance of Highly Pathogenic Avian Influenza Viruses in Poultry, Wild Birds, and Mammals to Prevent a Human Influenza Pandemic

“…From 2020 and during the COVID-19 pandemic, several important epidemiological trends in influenza A infections have occurred. Between the influenza seasons from October 2020 to July 2021 in both the northern and southern hemispheres, mortality rates from influenza fell dramatically [ 3 , 4 ]. During the COVID-19 pandemic, resources were directed toward monitoring and disease surveillance for SARS-CoV-2 infections, which raised concerns that undetected strains of influenza, including highly pathogenic avian influenza (HPAI), might result in an influenza pandemic [ 4 , 5 ].…”