I am utterly confused about the Oxford vaccine
There are many questions about the trial left unanswered
I am extremely confused, and I want you to be confused too. Normally I like to make things clearer for readers, but today I don’t think I reasonably can.
I wrote on Tuesday that we ought to be excited about the Oxford/AstraZeneca vaccine; I still think that’s true, but I have a lot of questions that I would like answered.
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In my piece I wrote that some participants were given a lower dose of the vaccine, then a standard dose booster, unlike most who got a standard/standard regimen. And people who were on the LD/SD were much better protected than those on SD/SD: 90% efficacy to 62%.
When you chop the data up into “subgroups” like this, you have to be careful that you’re not “noise-mining”. Say your drug doesn’t work overall, so you look at smaller and smaller subgroups until you find that a tiny set who happen to have done better, such as elderly hispanic women — but it was just a fluke result that you only got by torturing the data. For an intuitive explanation, see here.
This problem is much less likely if you specify in advance what you are looking at. I was told the trial did specify that in its protocol, but in that protocol the only mention of LD/SD comes on page 186: “Only participants who received two doses will be included (LD/SD or SD/SD)”. None of the tables seem to mention it that I can see.
I was assured that it was prespecified, but I really want to see that written down somewhere; I have looked at various Ox/AZ protocols (1, 2, 3, 4) and cannot find a simple timeline of what was specified when, and the regimen to have stemmed from an initial accident in which some people were given the lower dose. The excellent Jen Rogers, a clinical trials statistician at the consultancy Phastar, says that it may be an ad-hoc analysis done after the data was in — that is, at risk of noise-mining.
(Weirdly, in the Clinical Trials registry in the US, there is a mention in the earlier Phase 2/3 trial protocol of people having a full dose then a smaller booster, but not the other way around: see Group D here.)
Also, it seems that the group on the LD/SD regimen were all under the age of 55, which — obviously — is not the group most at risk. Further, because the LD/SD group was smaller, there was more uncertainty about the results, which is fine.
Partly this is the problem of science by press release, and as I understand it that’s a hard problem to avoid, because pharma companies are required to inform the market of upcoming results to prevent insider trading. That’s why we only saw headline results from Pfizer and Moderna as well. Oxford/AstraZeneca say full results will be available soon, perhaps early next week; also, the data only went up to the 3rd November, and more has come in since which may make things clearer.
I think we should still be excited. The trial was monitored by two independent statisticians at Oxford, AstraZeneca’s own statisticians, and then a separate Data Safety and Monitoring Board. (Incidentally, someone mentioned to me a few weeks ago that there was something weird with the DSMB on the Ox/AZ trial: unusually there appear to be two. I don’t know if that’s significant.) They have also been submitting data to the regulators as they go along. So it should be hard to sneak any really weird stuff through.
But I really would like to see the full paper, because I am utterly confused. And I hope you are too, because I think that’s the appropriate response.
While we are at it:
1. How is it possible to certify the long-term safety of a vaccine – a condition of certification of “worthwhile” efficacy – developed on a fast track process?
2. How will other potentially more effective vaccines be developed after licence of the first, since placebo-controlled RCT of a potentially inferior vaccine under circumstances claimed to be sufficiently dangerous to warrant catastrophic social and economic harm will logically be ethically unacceptable?
3. When will we discover the results of the investigation of the extent to which conflict of interest between government members and their business interests have compromised their decision to licence the vaccine?
4. Will Keir Starmer seek to have me criminally prosecuted for asking these questions, in his role as Leader of Her Majesty’s Most Loyal Opposition, charged with the responsibility of holding the government accountable?
Richard, it is not yet illegal to ask if some covid orthodoxy is inefficacious, although saying it is can get you prosecuted, and will get you banned from the usual social media platforms, and from The Guardian.
With therapy, I can probably come to terms with estrangement from social media platform and even the Guardian. Fines and Incarceration – not so much.
And what is the status of AZ being (already) given immunity from legal action in the event of future problems such as side-effects? The vaccine hasn’t been approved yet, serious concerns over methodology and rushing through Phase III are emerging and MHRA is nowhere near ready to conclude its findings – yet it appears AZ will be able to avoid liability if it all goes wrong. The City and Wall St. analysts clearly smell something is not quite right.
The rabid and premature exuberance (increasing desperation, more like) of Johnson & Hancock et al should also be a cause for concern, but only a minority of the cheerleading MSM is thus far asking the right questions.
Perhaps the 77th Brigade could enlighten us?!
I seem to recall a similar scenario back in 2009 with Swine ‘Flu and GSK’s Pandemrix vaccine. It was railroaded through with lashings of self-congratulation, political bandwagon riding and even admonition of us, the British public, for not taking it up in numbers/ with the appropriate sense of civic responsibility.
Just as well, since Swedish & Finnish studies revealed narcolepsy as a major side effect. Lawsuits inevitably flowed, but equally I seem to recall GSK secured upfront indemnity before rollout – as I understand the case to be with AZ here. A bit of a concern.
Swine flu “second wave” is infamous as the pseudo-epidemic with an infection rate that corresponded with the test false positive rate, and which therefore vanished the moment they stopped testing. At current government estimates of prevalence and false positive rate, up to 90% of current PCR test results have the potential to be false i.e. we are in a pseudo-epidemic.
> At current government estimates of prevalence and false positive rate, up to 90% of current PCR test results have the potential to be false i.e. we are in a pseudo-epidemic.
This is false. The ONS prevalance in England is 1/85 from
Coronavirus (COVID-19) Infection Survey, UK: 26 November 2020. The ONS worst case for PCR false positive rate is about 0.04%, which we can get from the summer when there was hardly any virus around, by assuming that all the positives seen then were false (they probably weren’t all false, but this gives a worst case).
[See Coronavirus (COVID-19) Infection Survey pilot: England, 17 July 2020 which says “For example, in our most recent six weeks of data, 50 of the 112,776 total samples tested positive. Even if all these positives were false, specificity would still be 99.96%” (and so the FPR 100% – 99.96% = 0.04%).]
Bayes Theorem says that the probability that you have the virus given a positive test is 95%, assuming a false negative rate of 30% (False Negative Tests for SARS-CoV-2 Infection ” Challenges and Implications). Even if the FPR is 1%, the probability that you have the virus given a positive test is 45%, not 10% as you claim.
Please expand your calculations and explain how you have used Bayes Theorum
Sure. We write probabilities like P(something) for “the probability of something” e.g. P(virus) for the probability that someone has the virus. Probabilities are fractions between 0 and 1, multiply by 100 to make percentages. Conditional probabilities are the probability of one thing given another thing has happened, for example, the probability that it will rain today given it rained yesterday. We’d write that with the given thing after a |, as in P(rain today | rain yesterday).
Bayes Theorem is just how you go from one conditional probability to one the other way around i.e. from P(A|B) to P(B|A). We want P(virus|test), we have some idea of P(test|virus) and some other stuff. Bayes theorem in the form we want for this says P(virus|test) = [P(test|virus) * P(virus)] / [P(virus) * P(test|virus) + P(not virus)* P(test|not virus)]
P(test|virus) is the so-called sensitivity of the test, the proportion of people with the disease who test positive. I took this as 70% based on the paper I referenced which said the PCR tests typically had 30% false negative rate. P(virus) is about 1/85 in England, or about 1.18% according to the ONS reference. P(not virus) is 100% of people minus those who have it, so 100% – 1.18%. P(test|not virus) is the false positive rate, which I took at 0.04% based on the ONS survey during the summer.
Plug it all in, P(virus|test) = (0.7 * 0.0118)/(0.0118 * 0.70 + (1 – 0.0118) * 0.0004), which Python helpfully tells me is 0.95 or 95%. What if the false positive rate is actually 1%? (0.7 * 0.0118)/(0.0118 * 0.70 + (1 – 0.0118) * 1.0/100) is 0.46 ie 46%.
The BMJ has an online calculator doing the same sort of thing but doesn’t allow fractional percentages. There are various other online calculators if you search for “Bayes theorem calculator false positive” or similar things.
Another thing I should add is that a test taken because of some suspicion that someone has the virus (because they have symptoms or have been in contact with someone who has it, for example) would raise that initial P(virus) pre-test probability from the population level, as David Spiegelhalter says in the David Spiegelhalter and False Positives video on YouTube.
I don’t know where to start with your daft analysis so I’ll just turn to the government.
On the 14th October regarding false positive rates on PCR tests:
“the United Kingdom operational false positive rate is unknown”
And the best they could offer on PCR in general: “a median false positive rate of 2.3%”.
No acknowledgement of how cycle amplification factors are major uncontrolled factor.
In any case, with a disease prevalence of 1% and FPR of 2%, 3 in 100 tests will result in positive outcomes only one of which is correct.
That is 2/3rds of all reported positive cases will be false. Obviously the proportion of false results increase as the disease prevelance reduces in the target test population.
This is why it is complete madness to encourage mass asymptomatic testing using PCR tests.
I have no idea why you think you (or anyone else) knows anything about current operational realities on PCR tests in the UK since there is no fixed cycle rate imposed by the government and no auditing of commercial labs for issues such as cross contamination. I’m happy to be corrected on this – so please provide evidence.
And by the way this is why 4 German tourists in Portugal have been successful in their habea corpus case against forced quarantine. The PCR test without corroborating symptomatic evidence is not fit for clinical purposes.
The theory is , that it is not possible for a virus to spread a disease, since it is not “alive”.
There is a Â£1m prize offered to anyone who can prove that a virus has caused a disease.
That still sits on the table
Indeed – and guess which epidemiologist’s model was relied upon?! Step forward Neil “pantsdown in lockdown” Ferguson! Incredible, yet here he is quoted at length in today’s Times…beyond bizarre.
And when the Swine Flu incident came up in British Medical Journal a couple of years ago (Correspondence: A tale of two vaccines) there was a letter from senior officers of the MHRA including its current head June Raine (currently being beatified in the Guardian) which was completely unapologetic for the fiasco. They were particularly lucky that only 10% of the population elected to have it.
How can the MHRA license these products – they will only have been tested for a very few months? Why is it even under consideration?
I hear you. But the political pressure to railroad this through will trump every accepted clinical standard and normal biotech protocol. Johnson & co are literally betting the shop (us / Britain) on this. I predict that they’ll either make it compulsory for us to be vaccinated or introduce a system under which those of us who don’t submit to their intimidation are disadvantaged civically, i.e., unable to travel, etc. In short a regimen equivalent to having to wear a gold star in reverse.
This is absolutely what will happen. The idiot Hancock has pretty much told us this.
Stop Press: A poll has found that almost half of doctors would not take a rushed Covid vaccine. A poll of readers of Medscape UK found that of 308 UK doctors, 4 in 10 would not get a COVID-19 vaccine as soon as one is approved by the MHRA. Medscape has the details.
Online polling took place 18th-23rd November after the positive Pfizer/BioNTech results but with most responses received before the positive news about the Oxford/AstraZeneca vaccine.
Of those who wouldn’t have the jab at this stage:
““ 56% cited safety concerns
““ 27% would rather wait
““ 7% mentioned personal health reasons
““ 14% had other reasons
Overall, 59% said vaccination for healthcare staff should not be compulsory. Among those who wouldn’t have the jab at this stage, nine out of 10 were against compulsory staff vaccination.
Great random sample !
Just over 250,000 licensed medical practitioners of various flavours, in the UK according to the GMC as of 2019
Their union (BMA) has negotiated a payment of Â£12.58 (Â£25.15 for two) for each administered vaccination – a surprise to those of us who thought that was was they were already paid to do.
So it will be interesting to see how many will refuse to give the jab and forgo trousering tens of thousands of quid, having refused to take the jab.
Although my comment is not on the Covid19 vaccine as such, thought I’d share it as it refers tomNHS G.P’s I have the normal flu jab every year, due to Asthma, but this year I wasn’t “invited”. I rang my surgery to book my next monthly blood test & asked about the flu jab. Firstly the receptionist said they were doing over 65’s as a priority & I’m only 59. She then said I could come along for one that Saturday. When I got there, I was shocked to see a number of the surgery doctors, so this is where they are! A friend said they’re doing it as they get paid extra? But I’m annoyed as they really put me off coming to the surgery for anything, the blood tests were first done in a gazebo attached to the fire door of waiting room. Then it was moved to just a small, cordoned off part of the waiting room. I have a disability & a few long term chronic health issues. I had a major fall outside on a path late September. An ambulance was sent for as I went right down on my front (walking stick in one hand) hit front of head & forehead, got badly bruised hip, knee & ankles. Paramedics took me home after treating my head/bleeding, told me to let surgery know. All that GP said on the phone was “call 999 if your head starts bleeding again”. I wouldn’t have thought of that, I live on my own, so no one to closely monitor me. A few weeks ago, now suffering with nerve pain in my legs, ankles & a knee don’t look right. Called surgery, another GP rang me & said would refer me to physio, not give more meds as on a lot. But physio is not helpful for this problem. They’ve now said if I want a GP to see me in person, have to call at 8 am & suppose wait most of day for one to call me & maybe ask to see me. This is why I’m so annoyed at seeing them at the flu vaccine session!!
You should start to take vitamins B and C. Stay away from doctors, and flu jabs (which don’t work)
I hope you feel better soon
In the US, apparently, first responders and the military will not be vaccinated. On the basis that they may well be on the front line of administering it, what does that tell you?
That says they expect bad outcomes. The military are usually the first to be vaccinated if they believe in it.
It’s a real shame that it should come to this. We need confidence in this vaccine but the data needs to be robust. There have been plans in place for the role out of two vaccines for some weeks now (long before Pfizer and AZ announcements) and it would appear that unless there is a raft of currently unprocessed data, the regulator cannot approve this vaccine until more phase III information is available. Combining disparate datasets is not good science. I can’t see how a statistician would support averaging SD/SD 62% and LD/SD 90% to get an overall efficacy of 70%. In the real world, you will only get one of those protocols so an average efficacy isn’t helpful. If the product is good and we’ve dropped the ball during the trials then that just about says everything for how this year has played out.
So when has your “good science” ever been part of this covid event, excepting maybe in the Wuhan lab. Also there is new advice from SAGE saying wearing a mask wile getting the vaccine also has talismanic effects on that, as masks do on so many situations, making the antibodies increase by 6-8%.
In Germany the dept for ‘Good Science thorough Homeopathy’ is excited about getting their hands on a sample of the vaccine so it may be diluted sufficiently so it will work at 100% instead of 90%. They believe one LD dose will be sufficient to vaccinate the world’s 7.5 billion.
Homeopathy is unlikely to use anything which contains genetically meddled animal, human and bird material as well as an adenovirus and a heap of synthetic chemicals.
Although apparently there is some research being done into using Homeopathic process to reduce the kill and injure rate of toxic medications.
A vaccine with 60% efficacy, quickly vaccining most people over 18, would totally transform life in the North West of England this winter.
The FDA in the USA set a target of 50% efficacy for approval of a Covid-19 vaccine back in the summer. There’s really no problem with a 60% effective vaccine but the trials need to support a transparent release of data. For one reason or another it seems as though the trials have been badly organised/delivered. And that’s a real shame.
Prof David Salisbury, immunisation expert and associate fellow of the global health program at the Chatham House think tank, said: “You’ve taken two studies for which different doses were used and come up with a composite that doesn’t represent either of the doses. I think many people are having trouble with that.”³
Indeed, but the issue is with a – dare I say it – misleading presentation which pushes up efficacy by averaging across two discrete groups. Even I with my meagre o level maths could work that out.
This efficacy is only measured by symptoms – it does not tell us anything about transmissibility or whether it kerbs fatality. If it masks symptoms it could just cause confusion.
The guy on Have I Got News for You, who’s Irish, just said it’s the most British thing he’s ever seen. They create an effective vaccine and everyone’s dying to pile in and see it fail.
OK there are questions for sure, but in fairness Chivers should point out that the AZ results counted asymptomatics as well as the properly sick, which the Pfizer and Moderna did not. Oxford looked a lot harder for the cases.
That alone could account for a difference and is at least as relevant. Chivers must know this. Why not mention?
Mock the Week?
I’m part of the trial. I don’t know if I had it or placebo but it is true that they are looking hard for asyptomatics as I have to be swabbed every week symptoms or not.
I’m not convinced by any of them, that even if they’re necessary they actually work. But since they’ll be more or less obligatory I’d prefer to have one that doesn’t seem as risky. Even better for me if it’s just a placebo, just to shut the govt up, and you know, get Britain’s ‘world beating’ economy going again scamming other people than just us.
Chivers is ridiculous. With a survival rate well over 99 percent what exactly are they trying to cure? You are so far out on the margins how would you ever know they work?
I think they’re trying to cure the govt’s standing with the public!
Finally asking the right questions Tom Chivers …
Well Tom, If you want to have Thimerasol ( Mercury derivative) Aluminium salts and aborted fetus tissue injected into your blood stream, then go ahead, because the above listed ingredients are 99% sure to be included in the vaccine. Oh, and did I mention that it will also have nanoscopic tracking devices within it also.
If you don’t believe me, go check it out and do some real, deep digging research.
Good Luck. John W.
Well said. I am horrified at the number of people on here who have swallowed this propaganda, and believe that anyone in their right mind would take this. They should watch the Ted talks Gates of hell , about how vaccines can reduce the world’s population from 7.8 billion to 700,000.
I think what is troubling is how increasingly experimental vaccines are, particularly involving genetics, and I truly doubt that science-medicine at this point in history, if ever, fully understands genetics, immune function and disease well enough to be able to categorically state that no vaccine could or would have disastrous effects further down the track.
Modern medicine has too long taken the delusional view that disease is caused by pathogens when patently that is not a given. Many people have H. Pylori in their stomachs and never develop an ulcer and many have Strep in their throat and never become sick. It is not the pathogen but the terrain, the body, and its ability to remain well.
If we get this wrong, and noted minds have in the past suggested as much, we are contributing to a future where generations have poorer and poorer health and less resistance to pathogens. There can never be a vaccine for every one of the many thousands of diseases which already exist, let alone those yet to develop.
As Judy Wilyman, PhD has written, Misapplication of the Precautionary Principle has Misplaced the Burden of Proof of Vaccine Safety. Science, Public Health Policy & the Law Nov 2020 2:23-34.
“In 1960 Macfarlane Burnet, Nobel Prize laureate for immunology, stated that genetics, nutrition, psychological and environmental factors may play a more important role in resistance to disease than the assumed benefits of artificial immunity induced by vaccination. He considered that genetic deterioration of the population may be a consequence of universal mass vaccination and he postulated that in the long-term vaccination may be against the best interests of the state.
The current belief that much of the burden of infectious diseases can be alleviated if every child, in every geographical location, has access to multiple vaccines, does not consider the influence of genetics and environment on the health of populations. The historical record shows that deaths and illnesses to infectious diseases fell due to public health reforms ““ and prior to the introduction of most vaccines.
Since 1990 there has been a 5-fold increase in chronic illness in children in developed countries and an exponential increase in autism that correlates directly with the expansion of government vaccination programs. Many individuals are genetically predisposed to the chronic illnesses that are increasing in the population and since 1995 governments have not used mortality or morbidity to assess outcomes of vaccination programs.
Human health can be protected in government policies if the precautionary principle is used in the correct format that puts the onus of proof of harmlessness on the government and pharmaceutical industry, and not the general public. This has not been done in current vaccination programs and we cannot rule out the possibility that the increased use of vaccines is destroying the genetic fabric of society as MacFarlane Burnet postulated.”
“the problem of science by press release, and as I understand it that’s a
hard problem to avoid, because pharma companies are required to inform
the market of upcoming results to prevent insider trading.”
And to prevent the wrong guy becoming President of USA. But then they managed to slide on that one too.
According to David Parker/Dawn Lester latest book, ” What really makes you ill”, so much of the nonsense being fed to us relies upon the idea that a virus can spread a disease, and a vaccine can be produced to combat it.
In the first instance, there is no proof that a virus actually exists. It has never been isolated, it has never been categorised, and nobody has produced a paper showing proof that a virus is the sole cause of any disease to which it is attributed. Unless these 3 things are produced as evidence, the virus does not exist.
How can anyone produce a vaccine to cure something, without first proving the existence of the virus ?
It is about time that journalists started to do some real investigations before writing anything either for, or against the subject of vaccine production.
Anyone who has conducted any research into what is behind the vaccines should just accept that it is the biggest money making hoax on the planet.
Quite apart from that, even the biggest vax hoaxer of all time, gates of hell, admits it would take at least 18 months to make, test and produce a vaccine.
This must be the most dangerous thing yet to come out of our thoroughly corrupt and sociopathic government. ,
The fact that the pharma industry has been given immunity to prosecution if their product causes harm illness, death, should be the biggest red flag evermore. You would need to be mad to take it.
It will make the number of deaths they have caused to date (from suicides, lack of medical care, forced mask wearing) pale into insignificance
The day that real journalists and the main stream media tell the public the truth, we can regain control of our lives and the country
I find your opinions depressing. Rightly or wrongly, people in westernised society now anticipate living into their 80s. That is largely in part due to the suppression of diseases that killed healthy children and adults in the centuries before this one. Take all vaccines out of the equation and let’s just say that we wouldn’t have to worry about retirement planning.
I won’t even begin to address your conjecture that viruses don’t cause disease.
You don’t personally take vaccines? Just be grateful that the rest of us do because they has greatly reduced your chances of getting polio, tuberculosis, measles, meningitis….
If you want a world without vaccines, you now have a glimpse of the international pain and distress that is caused by just 10 months without one vaccine.
As a physician over here in the States, I am amazed how people are falling the oldest book in the trick by Big pharma i.e. quote relative risk reduction as big “success” while there is absolute silence on the real number i.e. absolute risk reduction and hence the actual number needed to treat for 1 person to benefit. If you look at the crude,but limited data of the Pfizer vaccine approximate off the top my head would be approximately at least 15k people to the vaccine to prevent symptoms in one person (Just mental calculations, I would advise you actually look it up and do them yourselves, RRR, ARR and NNT). Also, what is considered by the FDA for the vaccine to be deemed efficacious is NOT hospitalizations or death,but presence of “moderate” symptoms.
What is most astonishing is that people are ready to accept and push, a highly experimental vaccine, in a form, never before approved, not properly tested against a placebo, which is likely to make recipients sick, to counter a virus which is no threat to the vast majority of people and even those who test positive, have no symptoms or symptoms so mild they do not count, i.e. they are not sick.
It is oxymoronic to make people sick with a vaccine against a virus which does not make most people sick.
What health issues arise over the next 12, 24, 36, 48, 60, 72 etc… months after taking the vaccine?
There are always adverse reactions to vaccines, what is the acceptable ADR rate?
What is the acceptable rate of deaths?
Think i’ll leave it and take the consequences, what about you?
Absolutely give it a miss. If Covid-19 were a Black Death scenario and the lives of children and the young were at risk, and there was a chance a vaccine might help, I would stand in line even though I have long avoided all vaccines. But Covid is no threat to more than 95% of people, some experts have said, 99.9% of people so why would one participate in an experiment which might do even greater harm and permanent damage?
When every single member of the Cabinet, without exception takes this Vaccine, in public, I will be convinced!
I read somewhere (damned if I can remember where! help if anyone can) that the USA will probably not licence this vaccine.
Indeed, and the AstraZeneca share price tanked in the US as a result.
Found it…..it’s in the FT. Apparently only 2300 people had the correct dosage and there are concerns around placebo variance from country to country. You are correct on the share price and to add insult to injury the other successful vaccine companies saw their share price rise.
I think that we should be told the exact nature of the placebo – I have heard – and no I can’t remember where – that unscrupulous companies fix the placebo to the advantage of the vaccine – I would welcome some comment on that.
There is no placebo. What they are calling a placebo is a meningitis vaccine. All vaccines carry risk, true placebos do not. How does one identify risk without a true placebo? It cannot be done. Ergo, safety tests for Covid vaccines are not being done and given its highly experimental nature, one would have thought they were even more critical. Well, for real science and medicine they would be, not the profit-driven Frankenstein fantasies we see churned out today.
The US trail is on going and has not yet had enough total infection in the control group. I expect within a few weeks there will be a lot more data for the US regulator.
There is a real issue, in that the US may not approve an vaccine that gives 60% protection if another vaccine gives 90% protection, even if most people will not have access to the “better” vaccine.
Yes and they are concerned that only under 55’s are in the trial.
It looks like we will have to wait for the publication of the full results before we have any clarity. I hope there will be an article about the full results and a link to them when they become available. I am still puzzled about how any conclusions can be reached from such a small sample, but maybe I am getting confused with other vaccine trials. I think 94 people was the number reported for one of them.
The trials are of tens of thousands of people. This is the sample size – and these are quite large for vaccine trials. The way conclusions are reached is as follows. If x people get sick in the vaccine arm and y people get sick in the placebo arm, if the vaccine were ineffective, what would be the probability of getting that result. If that probability is very low, they conclude that the vaccine works.
The actual calculations and underlying statistics/probability theory is rather tedious – but you could find it in most basic textbooks on the subject.
Now as regards the “Oxford,” vaccine, the group receiving the low start dose is not so large and none of them were over 55. Plus various 3rd party scientists have publicly commented that they can’t seem to match up the numbers and effectiveness %’s in AZ’s press release – not to the exact decimal at any rate.
“The Pfizer/BioNTech vaccine reports 90% efficacy, which means that ““ of the 94 confirmed cases of COVID-19 ““ their vaccine prevented COVID-19 symptoms for 90% of those who received the vaccine compared with placebo. This is very high and will probably change by the end of the study. The press release reported the results for 94 participants ““ they need 164 to complete the trial, which shouldn’t take long. Safe vaccines with efficacy above 50% are expected to be approved for COVID-19.”
The results seem to be based on 94 people out of the 10s of thousands. I think 40,000 was mentioned. While it may seem likely that it was the vaccine that prevented 90% getting the virus it seems too small a number to come to that conclusion, in my opinion. Even the 164 that they seem to need to complete the trial seems a small number. Especially when, if my figures are correct, about 20,000 participants on the placebo did not become infected.
Are not vaccines meant to prevent infection as opposed to diminish symptoms? It all sounds very dodgy.
You would have to be able to follow the maths, but you would do a calculation something like “What are the chances of observing a cases in the placebo arm and b cases in the vaccine arm if the vaccine has no effect”. Then stop the trial when a+b is sufficiently large to give a 99% probability. a+b can be quite small – that just drops out of the calculation.
Just doing a back of the envelope calculation of 9,000 @ 62% + 2,700 @ 90%, one gets 68.5% give or take. I guess 70% sounds better, but all in this smacks of haste and commercial / competition-related concerns.
The underwhelmed response from Wall St. & City pharma analysts & traders suggests they literally aren’t buying it. The FDA will have significant concerns and not being an US vaccine won’t be helpful either.
Surely it is also of deep concern that the vaccine is not being tested through comparison with a placebo?
It is disingenuous, if not dishonest, and certainly not scientifically or medically rigorous, to claim that a vaccine for meningitis is or could be a placebo. It is not. The comparison is with one vaccine against another. Since when did that become ‘gold standard?’
Given the experimental nature of this Oxford Covid vaccine, surely it is absolutely critical that any effects from it can be readily identified through comparison with a true placebo? Would that not be both good science and good medicine? Would that not be sensible and ethical?
Good on you for admitting you are confused. Indeed, the handling of this so-called pandemic has been all over the place from the start and singularly confusing.
Would you trust a confused surgeon to operate? No. So who on earth would trust confused Government, scientists, medical professionals or the media on the Covid topic? No-one of sound mind.
When Tom Chivers is confused about Big Pharma some truly nasty sh*t is going on in the world, that’s for sure.
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