It belongs in its own thread.
Grrrrrr. Reading more, it looks like the effective rate is based on the initial 94 participants and not the ten of thousands who have been given it. Also BBS reports
It does look like there are lots we don’t know yet.
This is not the case. The preliminary reports are based on the whole group of 40K+.
I know sometimes the scientific press releases can be a little confusing but it is worth clarifying.
Results are only looked at once 94 people in that full group were then diagnosed with Covid-19. Then those 94 are checked to see if they received the vaccine or the placebo and the 90%+ figure is derived from that. There will be a further read-out when 164 identified cases are seen and the efficacy will be further refined and more detailed findings provided on such things as efficacy/age/sex/ethnicity etc.
As you can see, this being the case it was never possible to put a definite date on when results would be in (because varying rates of infection in the population mean you’ll hit that “94 infections” target faster or slower accordingly).
Which also means that timing of announcements is linked to scientific reality not political expediency.
And yes, there are still unknowns regarding this particular vaccine but the big take-away is that it is possible.
Another issue is antibody persistence. I may have gotten the Pfizer vaccine, so to hear the 90% effectiveness figure was great news to me. But no one yet knows how long that resistance lasts.
True, It just hasn’t been going long enough to come to any firm conclusions on that.
The cases of re-infection seems rare. Given the millions of well documented cases if this was just a six-month protection we’d be seeing a lot more already so my gut feel is that this is more like a year+ for natural protection. It may be that the vaccine is even better but at least that protective window is enough to have a rolling program, just as with the flu.
One epidemiologist on the BBC last night said he’d never known a drug company to announce the results of a trial before it was finished and said it risked changing the behaviour of those participating in it.
My take on that is that the drug company have realised that storing and distributing this vaccine is going to be very problematic due to the requirement to keep in in deep freeze. To be generous they might be giving everyone a chance to find the way to do that. To be negative they know that nobody would favour their vaccine over a vaccine that was easier to store so they are cynically getting ahead of the game.
These aren’t the results, it is an interim analysis. It says it right there in the press release.
The full results and submission will be later in November.
Being in the business I can confidently say that interim analysis happen all the time. They drop into my in-box with regularity. They are seen as best practice because it is a chance to review how the trial is progressing, update on changes that may be required to trial sizes, length or early termination (for either good or bad reasons).
The timing is due to an independent assessment of what case numbers would be needed to make a statistically significant interim assessment of efficacy. The final result will come when a higher number of cases is seen (which has already been assessed as 164 cases across the full trial population)
Only problematic in terms of scale, such cold-chain logistics are already well understood.
The requirement for cold-storage of this (and many other candidate vaccines) was well known from the very earliest point in development, I don’t think this is a cynical ploy at all. The timing of the results was driven by the number of cases in the study population they were lucky that infection rates were high enough, and their study size big enough to allow an early read-out. It could have easily been one of the other vaccines that were in that position.
Thank you for fighting my ignorance @Novelty_Bobble! Are interim analysis usually announced publicly?
Obviously correct, but they couldn’t possibly have data on that yet.
That > 90% can be interpreted to mean that of the 94 cases of infection at most 8 were in the vaccinated group and at least 86 in the control group. If they were making this at the 5% level, it would require even fewer among the vaccinated people.
Other questions. How about older and younger people. I just read that they limited the test to people between 18 and 65. And how much is it going to cost?
Glad to help, The world of clinical trials is so highly regulated that it can be tricky to wrap your head around it.
As to your question, to the best of my knowledge yes. As Pfizer is a public company pretty much any major study milestone (for better or worse) needs to be public so that the relevant stock market valuation can be considered.
In this case I suspect that the massive level of public interest has shone a bright spotlight on a routine interim analysis. (routine in procedural terms but of course not routine given the current worldwide pandemic)
Makes sense thanks
I’m going to stick my neck out and say that the “above” 90% is significant and that they are purposefully pitching at the lower end of the confidence intervals. These people are inherently conservative. Were it in the region of 85-95% they’d go with the lower end and so that suggests to me that the actual figure is well above 90%.
HUGE CAVEAT WARNING - I’m just speculating. The purpose of carrying on to the 164 infection figure is to refine that figure, get greater certainty and narrow the error bars so things can definitely change.
I would not be surprised though, if the data continues in that trend, that it ends up in the 95% efficacy region, which would be remarkable.
This is the first mRNA vaccine in humans right? But it has been used in animals - how effective has it been there?
I posted this in the big “breaking news” thread, but it is more appropriate here:
MIT has a course on COVID this year, and anyone can audit it. You can either watch the lectures in real time (Tuesday 11:30AM, ET) or watch the recordings, which are posted a few days later.
Today’s lecture was very accessible to a general audience, and was about the development of the Moderna mRNA vaccine. That vaccine is extremely similar to the Pfizer vaccine, and should be releasing preliminary info later this month, or early December. (also determined by the number of infections among those in the study.) I feel much more optimistic after watching the lecture. The very-small-scale preliminary results, for instance, found good immunity responses in 100% of the (tiny number of) people studied, with immunity better than the average of the top 25th percentile of those who were naturally infected. But of course, the proof is in the pudding, and the lecturer said that she cried when she saw the Pfizer results.
The general press tells me that despite being almost the same technology, Moderna is testing the stability of their vaccine at -4F, a temperature achievable in most home freezers, and they are hopeful that will be good enough. -4F may not be good enough to vaccinate the 3rd world, but it ought to be manageable in most of the US.
Their vaccine also requires two doses – you could see the significant increase in response to the second dose in her slides.
Lecture 10: Kizzmekia Corbett, “Vaccines”
Also, researchers were able to leverage the work that had already been done on SARS-1 and MERS. Unless I misunderstood, they managed to developed the first doses of this potential vaccine just 3 days after the sequence of the spike protein was published, back in January.
This might be a stupid question, but if the vaccine is so fragile it has to be stored at -90 degrees how does it get warmed to a safe temperature to administer?
My guess is that they remove it from the deep freeze, let it warm up to ambient temperature but then have a narrow window in which to administer it.
it isn’t an exact analogy but think of this as a working piece of genetic code.
In the same way that sperm cells or eggs are kept in very cold conditions to retard degradation but need to be brought up to a suitable temperature to become workable.
This.
Think of it as like a piece of meat in your freezer. If it stays frozen it will keep for months, but once you defrost it you need to use it within a few days. This is the same, except the freezer temp is lower and the “time to use it” is a little shorter
https://www.reuters.com/article/health-coronavirus-vaccines-distribution-idUSKBN27P2VP
They can be kept in an ultra-low temperature freezer for up to six months, or for five days at 2-8 degrees C – a type of refrigeration commonly available at hospitals, Bencker said.
Here’s my favorite medical researcher’s blog post on the Pfizer vaccine. Which (unsurprisngly) echoes @Novelty_Bobble’s words above.
https://blogs.sciencemag.org/pipeline/archives/2020/11/09/vaccine-efficacy-data