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Checking In on COVID Vaccine Efficacy Against the Current Variants August 19, 2022

Posted by geoff in News.

Thought I’d check in on the COVID-19 sitch, ‘cuz it’s probably lonely. This time, instead of just looking at cases or deaths, I thought I’d see how the latest COVID variants are doing.

As you may recall, at the beginning of the year the Omicron variant (BA.1) rampaged through the population, though it didn’t seem much worse than a bad flu for most people. By now, though, the BA.1 variant has been supplanted by the BA.4 and BA.5 variants, with the BA.5 variant accounting for about 90% of cases in the US.

BA.5 doesn’t seem particularly dangerous, but I was curious about how the vaccines have been doing against it. So I ran across this article which talks about a South African study conducted to compare resistance to BA.4 and BA.5 for:

  • People who were vaccinated only (no boosters)
  • People who were vaccinated and had previous infection with BA.1
  • People who were not vaccinated and had previous infection with BA.1

Here are the results, where I’ve taken the liberty of simplifying their terminology (“50% focus reduction neutralization test value, the inverse of the plasma dilution required for a 50% reduction in the number of infection foci relative to the no antibody control in a live virus neutralization assay”) to just “relative resistance to virus.” [I plotted the inverse of their values.]

Natural immunity from an infection by the original Omicron virus outperforms the vaccinations, which were formulated for the original virus (Alpha virus?). Surprisingly, prior infection plus the obsolete vaccination does far better than the other two.

A caution is that the sample sizes they used were small, and the data scatter seems large, so these numbers could be wonky. But on the face of it, if vaccination is the foundation of our strategy going forward, they really need to roll out a vaccine that is contemporary with the predominant virus in the wild. Which they’re supposedly doing in a few weeks?

But I’m not very excited about running out to get jabbed with another poorly characterized vaccine.


1. alphaandomega21 - September 8, 2022

Dear Geoff

Many thanks for your post. As regards vaccines I have explained in a post why you should not touch them with the proverbial barge pole.


Kind regards

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