Vaccinated residents catch Covid
It’s alleged here that seven Maimonides residents who had their first vaccination have nonetheless caught Covid. If true, at best this means Quebec’s policy of indefinitely delaying the second dose of the Pfizer vaccine is not wise; at worst, the vaccine is bogus. Or the batch was bad.
LJ 17:36 on 2021-01-12 Permalink
Or it could be that they were exposed before or soon after being vaccinated, before it takes effect.
Chris 18:22 on 2021-01-12 Permalink
>at best this means Quebec’s policy of indefinitely delaying the second dose of the Pfizer vaccine is not wise
Not wise for who? Those particular people, or society as a whole? If the former, well duh. If the latter, then very debatable.
Also, although these people may now have covid, the effects could be reduced due to the immune system being more prepared from the first dose.
Kevin 18:28 on 2021-01-12 Permalink
If it’s 92 % effective after 3 weeks (and before getting a second dose) we should expect 8 people out of every 100 vaccinated to get the disease.
Blork 18:30 on 2021-01-12 Permalink
No, you would expect 8 out of 100 vaccinated and EXPOSED people to get the disease.
Chris 18:32 on 2021-01-12 Permalink
And by “people” that stat presumably refers to a random sampling of people: young, old, male, female, healthy, ill, etc. Maimonides are not such a sample. They are more like a worse case example: old and generally not so healthy. So we’d expect *more* to get the disease.
Blork 18:51 on 2021-01-12 Permalink
Also bear in mind that the more people get vaccinated, the fewer people there will be running around exposing people, so the exposure rate drops as well as the infection rate. They work together like that. (It’s not as if “exposure” were a constant.)
Michael Black 19:05 on 2021-01-12 Permalink
They decided people in “old age homes” were most vulnerable (and some of that vulneranility is because they are dependent on others to get through the day). Then it’s decided to not do the prescribed doseage “so we can vaccinate more people”. But if it doesn’t fully protect them, why bother?
A tiny percentage of people have been vaccinated. It won’t be speeded up by much if they only get one dose, and these are the previously described “vulnerable”.
Maybe later, when halving means a lot more people get vaccinated, but one hopes the vaccine comes more freely soon enough.
Everyone now wants to be first, everyone claiming their group needs it most. That’s a problem, and a problem only fixed by vaccinating faster and getting tge doses faster.
Chris 19:21 on 2021-01-12 Permalink
>But if it doesn’t fully protect them, why bother?
Uh, because partial protection is better than no protection!
You realize that not everyone in ‘old age homes’ has had a *first* shot yet, right? Should some such residents get two while others have had zero? Or should we get them all at least one, then starting giving seconds? Quebec has decided, in my view rightly, on the second course.
Once all the old age home residents (and health workers) have had one dose, we can argue again about how to proceed next.
Kate 20:56 on 2021-01-12 Permalink
Chris, Pfizer is threatening to withdraw its vaccine if Quebec doesn’t follow its dosing schedule. I wouldn’t be able to understand the science here, but I assume enough light has been shed on this matter that we can assume Pfizer is not doing this to angle for a bigger payoff, but to ensure that the vaccine is optimally administered. I tend to rely on science in this, rather than political optics. Your choice, of course.
Chris 21:22 on 2021-01-12 Permalink
>I tend to rely on science in this
As do I. Of course we don’t have perfect information to decide from, there’s conflicting evidence, and pros and cons to be sure. You might find this a good read: https://www.bmj.com/content/372/bmj.n18
Kevin 21:38 on 2021-01-12 Permalink
Blork
I’m afraid that’s not what efficacy means.
(This problem comes up a lot when talking science. Scientists use jargon which sounds a lot like normal English.)
“Scientists can calculate how well a vaccine candidate works by looking at the difference in new cases of the disease between the group receiving a placebo and the group receiving the experimental vaccine.
This is called vaccine efficacy. For example, Pfizer/BioNTech reported an efficacy of 95% for the COVID-19 vaccine. This means a 95% reduction in new cases of the disease in the vaccine group compared with the placebo group. ”
https://www.medicalnewstoday.com/articles/what-is-vaccine-efficacy
Alison Cummins 21:55 on 2021-01-12 Permalink
Old people often mount a less-robust immune response to vaccinations. They’re both more vulnerable to the disease and more difficult to protect.
I’d imagine that if you were going to vaccinate old people you’d want to be sure they got both shots. It might be more effective to fully-vaccinate the people they are in contact with, instead.
This is the kind of thing we can speculate about now but will know more about later.
Joey 22:12 on 2021-01-12 Permalink
Kevin, I’m pretty sure that’s incorrect. I’m also pretty sure your second comment is inconsistent with your first. See here: https://www.reuters.com/article/us-health-coronavirus-vaccine-efficacy-e/shot-in-the-dark-early-covid-19-vaccine-efficacy-explained-idUSKBN27S2EI
The 95% figure means that 95% of the cases observed among the vaccine and control groups after 14 days (or however long) were recorded in the control group. The Pfizer trial recorded something like 160 cases among 40,000+ participants. If 8% of Maimonides patients got COVID after their first dose that’s because the disease is rampant in that hospital.
nau 09:56 on 2021-01-13 Permalink
Regardless of how exactly vaccine efficacy is defined, the interesting distinction in those articles is between vaccine efficacy and vaccine effectiveness. Vaccine efficacy measures how the vaccine performs in controlled trials and is used to determine if the vaccine performs well enough to be approved for use outside of trials. It does not tell us beforehand what percentage of vaccinated people will get sick when the vaccine is then actually used. Vaccine effectiveness measures how the vaccine actually works when used in everyday conditions. These two measurements are not expected to be exactly the same, and so we can’t predict in advance what percentage of vaccinated people will still get sick by using the percentage score of vaccine efficacy.
One CTV article from Dec. 15/6 (titled Only 40% of Maimonides staff…) I read stated that 143 patients were vaccinated at Maimonides. Perhaps more were vaccinated in subsequent days. Either way 7 out of 143(+) would be a vaccine effectiveness better than the announced vaccine efficacy (though too small a sample and too soon to make a meaningful comparison), so I don’t see how this story tells us anything about the quality of the vaccine or the effect of delaying second doses.