August is the traditional Australian peak influenza (flu) month. The peak can move around a bit but it usually flu virus party time, followed in size by September.
Confirmed influenza cases, Australia, 1992-2018. Click on image to enlarge.
We’re two-thirds of the way through August Down Under and, well, it’s been a wimpy flu season.
Don’t get me wrong – after last year, that is greatly appreciated.
So far in 2018 – and the year isn’t over yet – we’ve seen that having lots more flu testing equipment does not a bigger flu season make. Something worth noting in the absence of relevant studies because it backs up that last year was just a jumbo transmission and illness year.
Highlighting when current PCR-based testing methods came into play. Not every year has been bigger than the last.
It will take some research to better understand why this 2018 season has been so small. Off the cuff though, some reasons include:
- a buildup of community immunity due to so many infections by a range of flu strains in 2017
- high levels of flu vaccination in 2018 having the desired effect – especially likely if the vaccine is a good match for circulating strains as it seems to be.
Although, a recent news story suggests more than 75% of young Australian children eligible for the free vaccination in 2018, did not have parents seek it out. - domination by other interfering respiratory viruses that have sent flu viruses to the corner to sit this one out. There has been lots of rhinovirus and respiratory syncytial virus activity this season.
Let’s watch the rest of the season though because, with flu, you never know what the next sneeze might bring.