COVID-19 vaccine boosters are urgently needed to counter an upturn in infection rates among the over 40 year-olds in Australia

The Pundit jumped at the opportunity to bring forward his Pfizer COVID-19 vaccine booster a few days ago.

Here's why.

Infections in older age groups are on the rise in the main Australian cities, Melbourne and Sydney, and the Pundit lives in Melbourne.

Here's what Twitter is noticing in these cities, against a backdrop of high vaccination coverage.

First New South Wales and Sydney.

In the most recent weeks, the risk of infection for older people has started to rise.

In Victoria, (and it's main city Melbourne), a similar trend has set in:

(h/T @dbraevn)

The Pundit is old , and plays close attention to these risks at the moment.

Here's what he sees with a different way of analysing the same infection trends for Victoria, that are largely based on Melbourne COVID-19 case numbers:

For the this graph the risks of infection are standardised, so that if every age-group had the same risk, the vertical axis values plotted would be 1.0, and the same as the overall population infection risk level (infections/per person) in each time interval examined. This is set to 1.0 as the risk level benchmark for simplicity and clarity about relative risk.

 Different time intervals through the recent weeks of the outbreak are plotted as different coloured bars, with different age group clustered together. Each time interval chosen corresponds to about 9000 diagnosed COVID-19 infections. All detected infections in the state were examined.

Firstly, the graphic shows that the relative risks are above one for people under 20. School-age children are much more likely to be infected than the average person (about 1.5-fold).

Second, people 50 and over are less likely to be infected (approaching 0.5-fold the risk).

Presumably this is because of less active social lives and strong vaccine coverage

The risk trend for the oldies is up.

But what worries the Pundit most is the trend over time in old age groups.

These are consistently showing a rise, as can be seen from the upturns within the relevant clusters on the graph.

Here is a different plot to demonstrate directly these observations using pooled case numbers for larger ranges of age groups (again, in the state of Victoria):

The Warning Sign.

Since 23 November 2021, the relative risk of infection for those over 39 is on a consistent rising trend over time.

Most likely this is due to the waning of vaccine protection from coronavirus protection. The change is not dramatic, but the steady rise is a timely warning:

Old people in both NSW and Victoria should get their boosters now.

Bear in mind vaccination will most likely soften the impact of the most recent Omicron variant of SARS 2 virus that is spreading rapidly in Sydney these last few days.

These protective decisions will ensure a more peaceful Christmas and New-year holiday period for all.