These numbers do not tell us much about the efficacy of the vaccine given the fact that there are so many possible confounding variables in the sample populations. For example, maybe exposure and transmission factors were different in the vaccinated population. What were the vaccination rates while the mortality numbers were collected. In other words how many people were vaccinated during Feb, March, etc ... of those.
Oldhat, if I squint hard enough I can sort of see that you're almost making a good point here, and I'll help you with that. But first let's make sure we know what we mean by
efficacy.
"
Efficacy is the degree to which a vaccine prevents disease, and possibly also transmission, under ideal and controlled circumstances – comparing a vaccinated group with a placebo group.
Effectiveness meanwhile refers to how well it performs in the real world." ... from a simple Google search for the difference between the two terms. (For those who disparage Google, you can find the same definitions in an epidemiology textbook, if you prefer, but it'll take you longer to find it.)
So what you're actually asking about is the effectiveness, not the efficacy. The efficacy is defined in trials, and is a more theoretical concept. The effectiveness is derived from actual use data, which is almost always a lower number than the efficacy. So in a hypothetical example, vaccine developers can say that a vaccine has an efficacy of 95%, but in the real world under real use conditions (which is affected by all manner of variables like exposure rate, compliance with the vaccine schedule, etc, as you point out) the vaccine's effectiveness will almost always be lower than the efficacy.
As an example, you can look at the earlier shingles vaccine, which came out about 8-10 years ago, which had an efficacy of 90+% in trials, but in actual use had an effectiveness of less than 50%.
In this case we don't actually have enough data to get a true number for the CoV2 vaccines' effectiveness, because it's still early in the study process. We'll have a pretty good number by early 2022, I expect. But these Texas numbers, which btw line up with similar data from all other states in the CONUS that I'm aware of, are HIGHER than the "theoretical" efficacy of 95%.
This is not something you can quibble about. This is not something you can say is confounded by a bunch of other factors. The success is unquestionable by any measure you can name. Using the word
maybe, as you have done, is much like saying, "let's pretend...". It's a dodge, no more and no less.
"Maybe something is messing with those numbers, so I'm not going to give them any credence." This is the sort of thing that people say when they have decided they are not going to accept a set of facts that contradict what they are determined to believe no matter what.
Now: is the actual effectiveness of the CoV2 vaccines going to come in at 99.995%, as these raw Texas numbers seem to say? Almost certainly not. But it's pretty much clear that it's going to come in somewhere in the ballpark of the initial efficacy percentage from the trials.
