According to this article, the UK lockdowns have had the effect of virtually eliminating Flu. As most of Europe/ The World has seen similar lockdowns, my expectation is that this would be reflected in other countries too.
As Flu is an ever-changing virus, existing outbreaks are used to determine what next years Flu Vaccine should be.
The World Health Organization (WHO) has a global network of 147 laboratories in 110 countries monitoring influenza outbreaks.
The data collected informs which strains should be vaccinated against for the next winter.
The aforementioned article details this is usually a challenging process.
So, with the lack of Flu this year, will this pose a problem for those making a Flu vaccine?