US & Canada: Examining the impact of vaccines
I just created a post explaining a new dashboard created and some of the slightly tricky calculations involved. Readers were instructed to skip that post if they did not have technical interest. Nevertheless, I will use the fruit of that labor to present some findings here (and perhaps subsequent posts). Here I will do a quick summary of what I see in US and Canada (used dates 3/15/20 - 12/31/22)
United States
Observations:
The number of COVID deaths during the period of zero vaccination (320K) is very similar to the number of COVID deaths after the US reached >60% fully vaccinated (332K). The latter is a longer period (60 vs. 40 weeks), so the deaths per week is ~33% lower in the 60-80% vaccination period. Looking at the graph (middle of 3 line charts), this deaths fell dramatically starting last winter (cough, cough… Omicron) and have not spiked significantly since.
The case rate is ~2X higher in the 60-80% vaccination period as was in the Zero vaccination period.
Excess Mortality remains stubbornly high. I suspect the last number here is a low estimate as the US is particularly slow in reporting all cause deaths.
Canada
Observations:
The number of COVID deaths during the period of zero vaccination & 0-20% (26K) is very similar to the number of COVID deaths after the Canada reached >60% fully vaccinated (23K). The 45 weeks with vax rate >80% are not too far different than the 43 weeks with zero vax in terms of deaths (13.5K former, 15.9K latter)
The case rate is ~5X higher in the 60-80% vaccination period as was in the Zero vaccination period. The case rate is ~2X higher in the >80% vaccination period as was in the Zero vaccination period.
Excess Mortality is the worst in the 60-80% vaccination period. I don’t trust the “0” in the last row as if you look at graph (bottom of 3 line charts), looks like data is delayed.
I’m trying not to be in the business of unfounded commentary, but I must say that I find the results above to not be very supportive of a “miracle” vaccine. There are several reasons we would have expected improved results over time even if a vaccine never existed:
Many of the most vulnerable were the 1st to get COVID & get seriously ill or die
Millions got COVID and survived. Immunity from prior infection is at least as good as vaccine (of course it’s better, I’m just trying to be nice).
Treatment should have improved dramatically over time
Omicron by all accounts is much less serious.
I will continue this line of analysis with other countries in near future.
Dashboard here: Global Data from OWID
Also - it may be useful to link to the previous post
The expectations list is problematic. 2020 waves reversed with seropositivity and experienced illness still ultra-low, 3 - 10% in lockdown countries. In the West only Sweden and Italy were higher https://onlinelibrary.wiley.com/doi/10.1111/vox.13221 - Granted, the dead can't contribute to seropositivity, but deaths were essentially rare vs. population, so the AR among "susceptibles" would be the same as overall AR, with a possible caveat for locales that turned nursing homes into hotspots.
So there's no grounds for asserting that susceptibles have been removed. Presumably only 3 to 10% of them have. There's lots of shoes left to drop.
As such, any gains in fitness / virulence would at best have a .1 discount from prior immunity / removal of susceptibles in most countries. .1 is a rounding error in terms of the possible delta of mutations on fitness / virulence. Given that the "reward" for increased fitness is an additional 9 times as much infection and replication as achieved in the first wave, i.e. the conquest of that remaining 90% of hosts, there's no reason to expect any reduction in deaths in future waves per se. And this just repeats for all additional waves up to Delta, because they keep ending with not much movement on seropositivity.
Only in the Omicron era can you start to include accumulated natural immunity as a serious factor in expected/observed epidemiology/evolution. Hence why it is only recently that there has been a lot of actual immune escape mutations, whereas the 2020 VOCs had one or two escape mutations to their name at most.