Part 2. Vaccination is now saving 4 lives among the 1000 Sars-CoV2 infected people a day in New South Wales, and that's without factoring in infections it prevents.

 Correction 4 November 2021

In a later post in this series we show with better data analysis that the vaccine is saving hundreds of lives

In the last several posts, the Pundit has been grappling with how to identify beneficial public health signals in the the New South Wales COVID-19 outbreak. 

Last week's statistics for daily deaths from COVID-19 are now available from New South Wales health press releases

Here is the series of weekly death totals using these press reports and other New South Wales government COVID-19 weekly surveillance reports:

At long last we can see (week 38) a decrease in the total of COVID-19 deaths. That is to say for total weekly deaths for the week ending 25th of September.

This week has also seen also seen drops in weekly numbers of new cases. But deaths lag about 11 days after the start of disease, according to New South Wales weekly surveillance reports on this outbreak.

This means that the decrease in deaths is not fully explained by drops in numbers of infections per week.

This line of thinking makes the Pundit think that the chances of each infected person dying are -- on average -- also decreasing.

How do we figure out if this is true?

As a start, look at what happens when you plot recorded cases per day and recorded deaths per day over a time period of 45 days at the start of the outbreak.

In this graph, cases each day are divided by 100. Deaths of the raw numbers of COVID-19 dead each day-- 11 days later than the corresponding case number day.

Both numbers are the cumulated numbers at the day in question.

The most remarkable thing about this plot is is that 1.0 percent of cumulative cases tracks very closely with cumulative number of deaths 11 days later.

This strongly demonstrates that in the initial days of the New South Wales COVID-19 outbreak, the case fatality ratio was close to 1.0 percent.

This is a seriously sobering percentage of death per infected case.

This is not flu.

But wait. There is a kicker.

But the kicker is that the graph that you get by plotting all of the cases so far available in New South Wales up to 25th of September 2021 is a closely analogous but distinctly different graph:

Although the graph plotted in the same way as the previous graph, at the end interval of the outbreak there is significant divergence between deaths and "case numbers divided by 100".

This proves that the  COVID-19 death ratio (deaths per diagnosed case) is dropping to less damaging levels in the later days of this outbreak, most likely in a progressively increasing and favourable fashion.

Infection fatality ratio has changed from 1.0 percent to 0.66 percent.

It's quite simple to do further calculations on the last 10 days of available data and infer that infection fatality rate has now dropped to 0.66 percent (from the initial value of 1.0 percent).

The risk of death in infected people has decreased absolutely by 0.44 percent or relatively speaking by 44/100, or a 44 percent drop.

Thus the most important conclusion from these calculations is that vaccination  in New South Wales is already saving the lives of several infected people per day. 

At the moment about 1000 people are still getting infected every day. Sadly in the coming days 6 will still die every day, but this number will hopefully drop further due to protection from infection and protection from severe disease thanks to vaccinations.

The Pundit is happy for any reader to publicise this post by any channel they see fit, and will listen to any critical comments about these conclusions.