Here in Canada, we've had the mix-n-match push in June - a large Pfizer shipment was delayed and there was tons of Moderna, and entirely coincidentally at the very same time mix-n-match was approved, and the official line became "mRNA vaccines are 100% interchangeable. You get what you get. Vaccine shoppers are horrible ignorant people. The science on this is settled." With all the attendant media propaganda (is it still propaganda when its perpetrators are certain it's for a Very Good Cause?)

At the very same time, the CDC website said that mixing vaccines is *not* recommended, in nice bold letters. Our Canadian science was special though.

As you say, when we learn new things about these (generally very safe) vaccines, this is great for science, but not so much for people who constantly evoke it to conceal that their decisions are also about politics and logistics.

I just wish these public health boffins would drop the holier-than-thou smugness and stop treating the population like they're simpletons undeserving of the gory details. And the details are gory, necessarily so, in the middle of a pandemic when you're faced with tons of lesser-of-two-evils choices.