“We were very lucky in the 2019/20 influenza season because there was not much of an overlap between the flu and the coronavirus epidemic,” said Professor Florian Krammer of the Icahn School of Medicine at Mount Sinai⁽¹⁾ addressing the European Scientific Working group on Influenza⁽²⁾. “There was a very low chance of getting infected by both coronavirus and influenza.”

If influenza and SARS-CoV-2 were to coincide 

Seasonal influenza is predictable. It comes back every year, he explained. “We know when it is going to come, and we can prepare for it.” Nevertheless, a strong influenza season can bring healthcare systems to the limits of their capacity. Usually they can deal with it, but it’s problematic.

Imagine a flu epidemic coinciding with the current SARS-CoV-2 pandemic, which has pushed healthcare systems beyond their limits in many countries. Hospitals would not have the capacity for that.

Co-infections with SARS-CoV-2 and influenza viruses have already been reported, noted the Professor. “It is very likely that being infected with two pathogenic viruses will be a problem for your immune system,” explained Professor Krammer.

How we can help lower the risk of influenza and SARS-CoV-2 colliding

We have one good thing on our side: there is a vaccine against influenza, highlighted the Professor as he stressed why this is important:

• We need to keep people from getting influenza to ensure they don’t burden hospitals that, at the same time, have to deal with COVID-19.
• We want to avoid people getting co-infections in general because we assume the outcome is not great.
• If you have a hospital full of SARS-CoV-2 patients and you send a flu patient there, the chances are relatively high that that person contracts SARS-CoV-2 as well.
• If somebody comes to the hospital with respiratory problems, it will be hard for healthcare workers to judge whether they have influenza or COVID-19, and that might make a difference in how they manage that patient.

Flu vaccination is vital

“It is important that everybody gets their flu shot to avoid problems with co-infection if these two epidemics collide,” emphasised the Professor.

After all, influenza is always unpleasant but usually mild, and most people recover quickly⁽³⁾. While most people recover from fever and other symptoms within a week, influenza can be severe, especially in people over 65, young children, pregnant women and people with long-term health conditions.

And the best way to prevent or minimise severe disease from influenza is timely vaccination. When influenza starts to spread every winter, WHO strongly recommends that those most at risk get vaccinated against the disease.

Professor Kramer concluded: “Influenza vaccines are very, very safe, so there is no problem using these vaccines in widely large populations. We have the vaccines at hand to mitigate influenza infections – and to and help to avoid the bad effect influenza infections might have during a second wave of SARS-CoV-2 infections.”

The best way to prevent or minimise severe disease from influenza is timely vaccination.
Have you had your flu shot?

References
(1) https://icahn.mssm.edu/profiles/florian-krammer
(2) https://eswi.org/eswi-tv/intervention-strategies-for-covid-19-influenza-and-rsv/
(3) https://www.who.int/emergencies/diseases/...that-causes-it