2021-05-26 BC

Vaccinations

On a COVID Slack channel that I frequent, the question has come up: “Why are we sitting on 127,917 AstraZeneca doses? If we are saving them for second doses, why not use them as second doses?”

I think that’s an excellent question, and we’ve come up with the following possible reasons:

  • They are scared of someone getting a clot and dying, though the odds are much lower with a second shot (about one in a million) that the a first shot (about one in 100,000).
  • They didn’t want to give the perception of inequity, with the AZ recipients getting their second dose faster than the mRNA recipients.
  • Given that they only have enough doses for about half of the 276K AZ recipients, they didn’t want to have to face 276K AZ recipients getting scared that they wouldn’t ever get their second shot.
  • They would prefer that AZ recipients get Pfizer as their second dose because they think it highly likely that getting AZ+Pfizer will prove to give better protection than AZ+AZ. (I also think that, based on my past experience, what experts have been saying for a long time, and this paper which says that AZ+Pfizer gives seven times as many antibodies than AZ+AZ.) The results from the big UK mix&match study should be out any day.
  • They believe that a longer delay is better (e.g. as this study shows) and worth waiting for.

Sooo on Monday I posted this long bit about why I didn’t think we were going to see cases go away until we had like 85% of people with two doses. Then, yesterday, the province released a restart plan with much much lower numbers — Stage 4 only requires 70% of adults to have one dose.

What gives?

I believe the difference is that Public Health wants the case counts low enough that they can manage the cases, not eradicate the cases. There is also a stipulation that to get to Stage 4, cases and hospitalizations must be “low”, not just “stable” or “declining”.

Is 70% of adults with one dose low enough? I don’t know, but I also know that we are absolutely going to crush that number. At the end of today, we had 65.8% of adults vaccinated; Stage 2 only requires 65% of adults vaccinated and we only started Stage 1 yesterday!

The advance-to-next-stage criteria also have calendar dates on them.; Stage 2 is three weeks from yesterday. Some people are wondering if maybe the vax rate has to be the number who have been vaccinated and have had three weeks for their immune system to finish training. In that case, we’ll hit the Stage 2 vax target on 16 June instead of 15 June.

Me, I think Pub Health is just completely sandbagging, giving us goals which we will reach with ease.

Statistics

Today: +250 cases, +3 deaths, +49,034 first doses, +3,430 second doses.

Currently 296 in hospital / 97 in ICU, 3,580 active cases, 137,517 recovered, 55.4% vaxxed, 65.8% of adults vaxxed.

We have 519,609 doses in the fridges; we’ll use it in 10.5 days at last week’s rate. We’ve given more doses than we’d received by 8 days ago.

We have 391,843 mRNA doses in the fridges; we’ll use it in 8.0 days at last week’s rate. We’ve given more mRNA doses that we’d received by 6 days ago.

Charts

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