Healthcare systems are preparing themselves for an emergency as the ongoing COVID-19 pandemic will overlap with the impending wave of seasonal influenza infections. Compliance with well-known infection prevention measures will determine how critical the situation will be.
As we head into autumn in the northern hemisphere, the seasonal flu is beginning to spread. Thousands of people are hospitalized each year as a result of the flu, with some years more severe than others. In the 2017/2018 flu season, 60,000 people were hospitalized in Germany alone.  As the ongoing coronavirus pandemic is already placing pressure on healthcare systems, hospitals around the world are bracing for capacity shortages, especially in intensive care units.
Just how bad the situation will be depends on how the two infectious diseases develop over the next few weeks and months. The influenza virus has shown quite variable activity in recent years, which makes it difficult to predict its course.
This year, critical focus areas include preventing the collapse of healthcare systems, as well as individual protection from infection itself. A recent study by researchers at the Max Planck Institute for Infection Biology in Berlin shows how impactful influenza and corona are. According to the researchers, influenza diseases increase corona transmission by a factor of 2.5 on average. In order to reduce this interaction and the general risk of infection with the influenza virus, the Standing Commission on Vaccination (STIKO) at the Robert Koch Institute strongly recommends getting the flu vaccination, especially for high risk groups, including individuals over the age of 60, those with chronic illness, and pregnant women.
Flu vaccinations and infection prevention measures provide protection
While many trials are currently underway, there are no proven vaccines against the novel coronavirus to date. According to the Robert Koch Institute (RKI), under the best-case scenario, a suitable vaccine will not be available until early into 2021.
Until a proven vaccine is widely available, we must refocus our attention on engaging in infection prevention measures each and every day: practicing physical distancing, performing thorough hand hygiene, and wearing a mask when out in public and when unable to maintain minimum physical distancing requirements. In Germany, this trio of measures is known as the “AHA” formula (German: Abstand (Distance), Hygiene, Alltagsmasken (Masks)). Recent research shows that in countries with good compliance with the AHA rules, 13.6 times fewer people died from COVID-19 between June 1 and August 20, 2020, than in countries with poor compliance. 
These infection prevention measures are even more important when we consider the fact that fewer people are opting for the seasonal flu vaccination.
The vaccination participation in the increased risk group – 60 years and older – has fallen from 35% to a meager 20 %. 
Even when a significant proportion of the population has opted for the seasonal flu vaccine, this does not guarantee protection against contracting the flu virus. Vaccinations against the seasonal influenza virus were only 30-60% effective during the 2019/2020 flu season.
“Individuals will play an important role in how the pandemic will develop in Germany. Protect yourself and those around you; please continue to follow the AHA rules”.
– Lothar Wieler, President, Robert Koch Institute
Experiences from the southern hemisphere
The 2019/2020 influenza season ended abruptly with the introduction of strict hygiene measures to contain the COVID-19 pandemic, clearly demonstrating the effectiveness of keeping your distance, practicing good hand hygiene and wearing masks in containing the flu season as well.
Data from the southern hemisphere also suggests the introduction of hygiene rules may affect the course of the 2020/2021 flu season. Out of the more than 83,000 specimens tested in Australia, Chile, and South Africa between April and July this year, only 51 tested positive for influenza (0.06% of cases). Compared to the same time periods in 2017-2019, more than 13% of cases analyzed tested positive for influenza. 
In this context, it is clear that the AHA rule is still a critical component in protecting yourself and those around you from contracting both the seasonal flu and COVID-19. By doing our best to adhere to important infection prevention measures, we can also support healthcare institutions in providing optimal patient care.
 Seifried J, Böttcher S, Albrecht S, Stern D, Willrich N, Zacher B, Mielke M, Rexroth U, HamoudaO: Erfassung der SARS-CoV-2-Testzahlen in Deutschland (Stand 26.8.2020). Epid Bull 2020;35:11–14 | DOI 10.25646/7113
 Ständige Impfkommission beim RKI: Stellungnahme der Ständigen Impfkommission (STIKO) beim Robert Koch-Institut (RKI) – Bestätigung der aktuellen Empfehlungen zur saisonalen Influenzaimpfung für die Influenzasaison 2020/21 in Anbetracht der Auswirkungen der COVID-19-Pandemie Epid Bull 2020;32/33:28–30 | DOI 10.25646/7040