It has now been more than two-and-a-half years since the first Covid-19 infections were reported in China. To combat the outbreak, the world gathered together in a coordinated effort to halt the spread of the disease. Central to this effort has been the global rollout of inoculations that included rapid development of dozens of vaccines (and several times as many candidates) and administering them to billions of people across the world.
The good news is that the death curve has broken away from the case curve
The good news is that in this spike, as was seen in the earlier Omicron outbreak in January, deaths do not appear to be showing an alarming rise yet. This trend has been consistent in the past year or so. The chart here has the case and death curve (the seven-day average for both parameters) plotted against each other in a ratio of 200:1 (which was the ratio of the peak of cases against the peak of deaths in the most fatal wave so far -- Delta). So, if the death curve is above the case curve here, it means that more than 2% of cases are dying in that time period, and if it is below the case curve, then fewer than 2% of new infections are resulting in deaths. Such a chart makes it clear that while deaths consistently followed the case curve through 2020 and 2021, it has stopped doing that in the past year and a half.
{{^htLoading}} {{/htLoading}} So, what appears to have been the cause for this?
Timing appears to be the biggest giveaway in understanding why deaths are not rising as fast as cases. The deviation in the two curves only becomes apparent in the final quarter of 2021, around the same time the global vaccination rollout started. As time has progressed, the gap between the two lines appears to only be widening as more people have been inoculated. This is also why the January 2022 (Omicron) wave saw nearly five times as many infections as the early 2021 Delta surge, but fewer deaths than the latter, another fact that shows how vaccination has changed the course of the disease.
{{^htLoading}} {{/htLoading}} Can we quantify how much better we are at saving lives?
The final question then emerges is how much better are we getting at saving lives. For this, we need to take a look at the case fatality rate (CFR) on a weekly basis throughout the two-and-a-half years of the pandemic. For an accurate understanding of the relationship between Covid-19 cases and deaths, one must take into account a 14-day lag. This is because studies have shown that the median time between someone testing positive for Covid-19 and dying from it (if things go south) is around 13.8 days.
Once adjusted for this lag, we are able to clearly see how the CFR has improved. While around 7% of cases were dying in the initial waves in early 2020, it was more so because doctors and medical apparatus had yet to be beefed up globally to fight a pandemic of this scale. Since then, the CFR largely settled around the 2% mark, rising through waves when hospitals got stressed under the weight of rising infections, and dropping as cases troughed.
{{^htLoading}} {{/htLoading}} All this changed in 2022. As vaccination was rolled out the world over, a drastic drop is witnessed in the running CFR, which dropped to an incredible low of 0.25% of confirmed cases resulting in deaths in the first week of July 2022.
A yearly CFR breakdown offers another outlook on this. Around 2.5% of all people infected with Covid-19 in 2020 ended up dying. This number was 1.7% in 2021, and dropped to 0.3% in 2022. Another way to look at this is that if anyone got infected with Covid-19 in the first week of July, the chances of them dying are 10 times lower than if they had got infected in any period in 2020.
Keep in mind that all these numbers, however, are a global average, so they also include regions with low vaccination rate as well as deaths among the unvaccinated.
{{^htLoading}} {{/htLoading}} Such an analysis gives us a good idea of what lies ahead in what appears to be a never-ending battle against Covid-19. As long as vaccination (which includes booster shots) keeps sufficiently protecting people from newer outbreaks, fatalities as well as disruptions to daily life can be contained, despite the occasional rise in cases and fresh waves.
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