And then there were two
We have data on a second Covid vaccine candidate, and it’s similar to the first one. Moderna released their first analysis results today: out of 95 cases of Covid, 90 were in the placebo group and 5 in the vaccine group . Even better, they had enough cases of serious disease to analyse, and these split 11:0.
Both of the vaccines use the same new technology, where little bits of messenger RNA, coding for the virus spike protein are introduced into your cells. Your cells make the protein just as if they’d been infected and your immune system reacts. At least, that was the theory, and it does seem to have worked. We haven’t heard from any of the trials using more traditional technologies, which would produce vaccines that are easier to distribute and may be easier to manufacture by the truckload.
The next important step, fairly soon, is an FDA external advisory committee meeting. This should be more informative than peer-reviewed publication: it’s peer review, but involving a lot more information than goes into a published paper, and a wider range of reviewers — and it’s done in public.
There are still problems to be considered:
- The vaccines have not been tested in children or pregnant women. That’s standard, except for treatments specifically aimed at children or pregnant women, but it’s an important gap. The pregnancy exclusion is probably less important from a public health point of view, since a very small fraction of the population is pregnant at any given time. Kids, though.
- We don’t know yet how long protection lasts — if it’s only a few months, that’s a problem
- We don’t know yet how much asymptomatic infection is prevented
- NZ doesn’t seem to have bought any of the Moderna vaccine yet — the Minister says we’re in negotiations
Also, these vaccines are going to have more short-term side effects than we may be used to: a lot of people will feel a bit average the day after a dose, and a decent chunk will feel pretty average. That’s going to help the vaccine misinformation pushers, especially if health authorities aren’t honest about it.
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »
Is just 5 in the vaccine group really enough to go public on your results?
3 years ago
The total number (hence, the number in the control group) is more important. Think about it: if the split were 100:0 that would be *stronger* evidence, not weaker.
3 years ago
> a lot of people will feel a bit average the day after a dose, and a decent chunk will feel pretty average
does “a bit average” mean mild side effects and is “pretty average” worse than average? non-native speaker of NZ here.
3 years ago
“A bit average” means unwell — mild side effects — and “pretty average” means worse than that. My Unified Kiwi Self-Rated Health scale goes “above average”,”average”,”a bit average”, “pretty average”, “pretty bloody average”
3 years ago