COVID-19 Vaccine Progress: Are We Ready for Rollout in Australia?

In summary: I do not know either - and the Flu does mutate - fortunately from what I have read Covid does not mutate as fast.I don't think so. A challenge trial is when you deliberately infect a person with the virus to see if they develop immunity. It seems like a risky and unnecessary step.ThanksBillI don't think so. A challenge trial is when you deliberately infect a person with the virus to see if they develop immunity. It seems like a risky and unnecessary step.
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We are starting to reach the stage when vaccines will be rolled out. I thought it was time to start a thread specifically on the state of play. Just an hour ago the following was published by an Australian newspaper (my precis):

'A vaccine will be available in Australia from the middle of 2021. Australian health officials are becoming more confident that they are getting closer to an effective COVID-19 vaccine, with hopes it will be here in about six months. Health officials are eyeing a mid-2021 rollout of what they increasingly believe will be a universally effective COVID-19 vaccine after promising data from major international trials. Teams tasked by the federal government to negotiate deals with vaccine manufacturers have poured over detailed studies and data, and have been encouraged by the early results of several efficacy trials. CSL would be able to scale up production within weeks depending on the type — with a year from now considered a middle-range estimate for a start date. CSL would be able to manufacture at least enough doses for Australia, New Zealand and the South Pacific and possibly other countries. One vaccine is believed to be the Oxford vaccine, being manufactured elsewhere by AstraZeneca, to produce doses domestically. The Health Minister Greg Hunt has declared he is “genuinely optimistic” about the situation, revealing the latest health advice was that Australia was “far more likely than not” to have access to a vaccine. “Until now we have been very cautious and have played down the possibility of a vaccine, there’s still no guarantee but there is real progress.” The question was whether there would be “partial” or “full” vaccines. A partial vaccine may need to be updated, it might not provide universal prevention but it does reduce the likelihood,” he said. We must complete phase 3 trials because we are going to vaccinate not just millions, but many billions.'

This could explain a number of 'anomalies' here in Aus where, for example, the UQ vaccine is asking for $4.5 million in public donations to get its vaccine out 6 months earlier. The government does not want to jeopardise delicate negotiations by handing out extra funding. Another vaccine they will not even return telephone calls on. Just a guess of course. Also Australia is, despite the Victoria outbreak which now seems to be coming under control, in a good position. For example here in Queensland where I live it is basically eliminated. Other countries need it more.

Thanks
Bill
 
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They had a mass test in a city with a major earlier outbreak here. 30% of those tested positive were later found without antibodies, and IIRC 7% tested positive again.

Even if those figures aren't representative, at least they show that vaccination might not necessarily protect people from getting sick anyway.
 
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fresh_42 said:
Even if those figures aren't representative, at least they show that vaccination might not necessarily protect people from getting sick anyway.

Indeed that is true. The flu vaccine is only 40% - 60% effective. If that is the same for an early Cornovirus vaccine, providing of course it is safe, then it will be of value. They also need to test if you get it while vaccinated if the death rate is lowered - that happens with the Flu vaccine.

This is the reason I do not think the Australian government strategy of not throwing money at the Australian vaccines is a good idea, but at least we now have a plausible reason for it.

Thanks
Bill
 
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I don't know why the flu vaccine is so poor, probably because it cannot cover all strains. In case of Covid19 the data seem to indicate, that the severeness of an infect is proportional to exposure and so are antibodies. This leads to the question to which extend can the vaccine simulate exposure?
 
  • #5
Just a question for the group. What is their view of challenge trials? Out here there is a debate, with some saying they are never used because of their inherent danger, despite only volunteers are used, and the WHO has guidelines on it. My understanding is they have been used before. I believe here in Australia we would get more than enough volunteers - even the thousands needed for stage 3 trials - but I think it will only used for stage 2 trials.

Thanks
Bill
 
  • #6
fresh_42 said:
I don't know why the flu vaccine is so poor, probably because it cannot cover all strains. In case of Covid19 the data seem to indicate, that the severeness of an infect is proportional to exposure and so are antibodies. This leads to the question to which extend can the vaccine simulate exposure?

I do not know either - and the Flu does mutate - fortunately from what I have read Covid does not mutate as fast. Regarding exposure could that be a reason to try challenge trials?

Thanks
Bill
 
  • #7
Wow - the results are coming in quick now. A new 'vaccine', but a bit different in that it must be taken 4 times a day as a nasal spray is in the works.

It was an accidental discovery about a COVID treatment - a nasal spray from pineapples. It is already far advanced in use by patients at Royal Melbourne Hospital. It is also planned to distribute to frontline health workers to prevent them catching the virus. Originally developed to treat cancer the drug BromAc has been found to dissolve COVID spike proteins.

Cancer specialist Professor David Morris from St George Hospital in Sydney has repurposed it into a lower dose nasal spray. “First of all we showed that it could dissolve the Covid spike that starts in the nose. Then we did work in France, in a viral laboratory with live virus and we were able to show that after an hour’s treatment with that the virus was not able to infect cells". The drug has already been trialled in much higher doses in 36 cancer patients where it extended their lives and has been found to be safe for human use. The treatment is made up of two ingredients already in for other medical purposes.

When COVID-19 arrived earlier this year Professor Morris noticed its spike protein was what is called a glycoprotein and BromAc may well be of use. The treatment will likely only work in the early stages of infection, it is not expected to make a difference once COVID-19 has already spread widely through the body and the person has developed serious illness. It will take just 48 hours to know whether the treatment works, and results from the upcoming clinical trial could be very swift, he said. Patients taking part in the trial will be given the nasal spray four times a day and will have a nasal and throat swab once a day to check the level of the virus in their body. The second use would be giving it to frontline health workers to prevent them catching the virus. There are already a million doses of the treatment ready to use, its cheap and Professor Morris wants to produce it in Australia. Putting his own body on the line Professor Morris used the nasal spray on himself. “I squirted the drug up my nose and into my throat. And I did that four times a day for a week. And I had absolutely no side effects”.

The theory is that once a patient is already infected with COVID, BromAc would disable the spike proteins of the virus stopping it spreading from cell to cell and spreading to the throat and lungs and throughout the body. “We also think that it will prevent the patient infecting others, because if the virus has lost all its spikes, as we’ve seen, and it’s unable to then infect cells then we should protect other people, and the patient from getting the disease,”

Interesting.

Thanks
Bill
 
  • #8
The New York Times has a nice page tracking the progress of the various efforts at developing a Coronavirus vaccine: https://www.nytimes.com/interactive/2020/science/coronavirus-vaccine-tracker.html

Here's a good page summarizing and comparing some of the preclinical studies in monkeys that have been published by some of the leading vaccine efforts: https://blogs.sciencemag.org/pipeli...0/coronavirus-challenges-in-primates-compared

bhobba said:
Just a question for the group. What is their view of challenge trials? Out here there is a debate, with some saying they are never used because of their inherent danger, despite only volunteers are used, and the WHO has guidelines on it. My understanding is they have been used before. I believe here in Australia we would get more than enough volunteers - even the thousands needed for stage 3 trials - but I think it will only used for stage 2 trials.

The main advantage of challenge trials is that you would need to test many fewer individuals to determine the efficacy of the vaccine than in a standard Phase II or Phase III trial. In a typical Phase II or Phase III trial, you take a population of people, give some the vaccine and others a placebo, and let them live their normal lives. Over the course of the trial, some fraction of that population will be infected with the Coronavirus from community spread, and you see whether significantly fewer got infected in the vaccine group vs placebo. Getting sufficient data required for the statistical analysis to be valid requires waiting quite a while. For example, even in countries with high infection rates (such as the US with ~ 50k new cases per day), this only amounts to 1 infection for every 6,000 individuals per day. For a trial with 1,000 participants, you would need to wait about two months to see 10 expected infections among the participants at those rates. In contrast, with a challenge trial, you could get similar results from challenging 10 volunteers in a week or two (the incubation time for the virus).

However, while the challenge trial can inform about the efficacy of the vaccine, it does not give information about safety, so large scale trials (with tens of thousands of participants) would still be necessary to test the safety of the vaccine(for discussion see this thread). In other words, a challenge trial could potentially tell you whether the vaccine is ineffective much faster than a normal phase III trial, but it would not obviate the need for large scale Phase III safety testing. The main advantage of challenge trials would be to help cull out any ineffective vaccine candidates so that researchers could focus resources needed for large scale trials only on the most promising candidates.

Although challenge trials are sometimes used in vaccine development, these are typically employed only when researchers have treatments that can cure any volunteers that acquire the disease during the trial (e.g. malaria). Obviously, this is not the case for COVID-19. While risk of death is low for young, healthy volunteers, many would still believe it unethical to intentionally infect young, healthy volunteers with a virus that could kill them.
 
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  • #9
bhobba said:
Wow - the results are coming in quick now. A new 'vaccine', but a bit different in that it must be taken 4 times a day as a nasal spray is in the works.

It was an accidental discovery about a COVID treatment - a nasal spray from pineapples. It is already far advanced in use by patients at Royal Melbourne Hospital. It is also planned to distribute to frontline health workers to prevent them catching the virus. Originally developed to treat cancer the drug BromAc has been found to dissolve COVID spike proteins.

I would not characterize this as a vaccine. It could potentially be prophylactic against infection by the virus (and other groups have developed similar prophylatics), but the need to continually take 4 doses per day is very different than the one or two doses necessary for a tranditional vaccine. A prophylactic may be appropriate for use in high risk individuals (e.g. pre-exposure prophylaxis is an effective strategy in the control of HIV), but it would not be as practical to the general public as an actual vaccine.
 
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Ygggdrasil said:
A prophylactic may be appropriate for use in high risk individuals (e.g. pre-exposure prophylaxis is an effective strategy in the control of HIV), but it would not be as practical to the general public as an actual vaccine.

Agreed. I was thinking of high risk people like first responders, medical staff, aged care staff etc. One big problem here in Aus is private aged care homes, in order to reduce costs, roster staff between different homes and can easily spread it from home to home. They all could make use of this kind of medication, should it prove effective. Also immediately anyone tests positive in an aged care home, or even traced to someone in a suburban home, they all could start using it. It looks like actually testing it can be done quickly and we already have 1 million doses available.

Areonabs that you linked to looks even more interesting since it only needs to be used once a day. I am starting to get the feeling we have more options to control this than is generally thought.

Thanks
Bill
 
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bhobba said:
Areonabs that you linked to looks even more interesting since it only needs to be used once a day. I am starting to get the feeling we have more options to control this than is generally thought.

As far as I can tell, the AeroNabs are only an idea at this point and there is no solid, publicly available data yet about use of this technique in people. There's no data to support the idea that it is effective with only one application per day. Of course, I have not seen any published data about the BromAc approach either, so at this point it is hard to compare the two approaches without seeing any clinical trial data.
 
  • #12
Ygggdrasil said:
Although challenge trials are sometimes used in vaccine development, these are typically employed only when researchers have treatments that can cure any volunteers that acquire the disease during the trial (e.g. malaria). Obviously, this is not the case for COVID-19. While risk of death is low for young, healthy volunteers, many would still believe it unethical to intentionally infect young, healthy volunteers with a virus that could kill them.

Thanks so much for clarifying. I know in the UK they are at least looking at doing challenge trials on the Oxford vaccine, but it is doubtful it will be done on at risk groups. It might be interesting to see what methodology they are using.

Thanks
Bill
 
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  • #13
bhobba said:
It might be interesting to see what methodology they are using.

I have investigated a bit more and found the following site:
https://1daysooner.org/

From another article:
Whereas traditional vaccine trials may enrol 30,000 participants in phase 3 studies and have results in 6 months, challenge trials may need only about 150 participants and have results in 6 weeks. In addition, the studies can compare multiple vaccine candidates at once; the most promising are selected to move on to larger studies.

Conclusion - risk with big reward. It would only be tried on young heathy people with a very small chance of dying. The risk is quite a bit less than giving a kidney which some very altruistic people occasionally do. An interesting ethical conundrum - but that is in the realm of the philosophy of bioethics which is not something we discuss here.

Thanks
Bill
 
  • #14
Big news for Australians - vaccine possible by years end (my precis)

Australia could have a Coronavirus vaccine by the end of the year as a deal to buy Oxford University's vaccine is approved. Australia will make millions of doses at CSL to distribute as soon as stage 3 trials completed. The government is also in negotiations to buy other vaccines if this one does not work. All 25 million Australians will be able to get injected for free just weeks after the vaccine is approved, which is expected to be late this year or early next year.

Prime Minister Morrison said: 'There is no guarantee that this, or any other, vaccine will be successful, which is why we are continuing our discussions with many parties around the world while backing our own researches at the same time to find a vaccine.' Australia is expected to spend billions of dollars on researching, buying and producing a vaccine.

Thanks
Bill
 
  • #15
The Stuff You Should Know podcast released a Short Stuff episode last week where they interview Bill Gates and discuss COVID vaccines .
The Gates foundation is involved in most of the trials around the world meaning Gates knows a lot about what is going on (including the politics).
I think it is probably the best summary I've come across so far.

https://www.iheart.com/podcast/105-stuff-you-should-know-26940277/

(scroll down to "The Return of Bill Gates")
 
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bhobba said:
I have investigated a bit more and found the following site:
https://1daysooner.org/

...risk...
This would be ideal for college campuses, where everyone is going to be exposed anyway, so the additional risk is zero.

#joking/notjoking
 
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  • #17
russ_watters said:
This would be ideal for college campuses, where everyone is going to be exposed anyway, so the additional risk is zero.

#joking/notjoking

The fatality rate for jobs in warehousing is 14.0 per 100,000 full-time years. Let's assume that college kids will find ways to kill themselves over the summer even if they are not employed in warehousing so maybe subtract the 2.2 per 100k for "leisure and hospitality services", so 11.8 fatalities higher. For covid19 in the 20 to 44 years old age group the fatality rate is around 150 per 100,000 infected. The study could set up a trust fund which pays an income for 13 years with the condition that the study participants only take jobs in professions with lower risk than leisure and hospitality services jobs( or just remain at leisure themselves). The infected group should have a lower fatality rate compared to participants in a control group who do not have the virus but do get jobs stocking Walmart, Amazon or UPS.

An extra month or two of quarantine next spring will expose more than 5 million logistics workers to both the virus and the overtime hours.

I think there are serious ethical problems with rushing tests for medicine. However, we are talking about choosing a study of 6,000 participants and waiting for results or 150 participants and getting the results fast. That cuts the risk of side effect by a factor of 40. We would still probably have to do the 6,000 just to test for long term side effects but the only danger is the virus exposure. Exposing the public to a virus would also be highly unethical. We clearly already failed on that front.

I am volunteer number 34,804. :)
 
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Challenge studies are interesting. They did it for Cholera, but when I mentioned it to my pharmacist he said in those days they were mad. I can see both sides, but a carefull analysis should be made.

Interesting here in Aus there is talk of the vaccine being mandatory. You are nutty saying that to Australians as it is likely to illicit the response - bu**er off. But saying nothing and you will probably get nearly everyone doing it voluntarily anyway. As the title of an old Australian film says - There a Weird Mob. My view is it should be voluntary, see what happens then decide on any further measures if required.

Thanks
Bill
 
  • #19
bhobba said:
Interesting here in Aus there is talk of the vaccine being mandatory.

That's just goofy - or way premature. Are you telling me the reaction should be identical for a vaccine that provides a little protection for a short time with a high incidence of side effects and one that provides full protection for a lifetime with few or no side effects?
 
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The AstraZeneca/University of Oxford adenoviral-vector vaccine encounters a setback as a participant experienced a serious adverse reaction to the vaccine.

A large, Phase 3 study testing a Covid-19 vaccine being developed by AstraZeneca and the University of Oxford at dozens of sites across the U.S. has been put on hold due to a suspected serious adverse reaction in a participant in the United Kingdom.

A spokesperson for AstraZeneca, a frontrunner in the race for a Covid-19 vaccine, said in a statement that the company’s “standard review process triggered a pause to vaccination to allow review of safety data.”

In a follow-up statement, AstraZeneca said it initiated the study hold. The nature of the adverse reaction and when it happened were not immediately known, though the participant is expected to recover, according to an individual familiar with the matter.
https://www.statnews.com/2020/09/08...d-adverse-reaction-in-participant-in-the-u-k/

One adverse reaction out of thousands dosed (the trial aimed to dose a total of ~20,000 with the vaccine, though I'm not sure how many have been dosed at the moment) is not necessarily a sign that the vaccine is unsafe, just that the company needs to review other data to make sure that others aren't experiencing similar adverse reactions before they can proceed to dose more patients with the vaccine.
 
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Nature just published a nice review article summarizing data from non-human primates and clinical trials for the various vaccine candidates currently in clinical trials. Here's a summary paragraph from the discussion:
For the vaccines in clinical trials for which Phase I/II data is available,
we observe both an immunogenicity and reactogenicity gradient.
In terms of immunogenicity, AdV5-based vaccines seem to rank
lowest, followed by inactivated and ChAdOx1 based vaccines, mRNA
vaccines, and finally adjuvanted, protein-based vaccines performing
best. Reactogenicity seems lowest in inactivated and protein based
vaccines, followed by mRNA vaccines, with vectored vaccines having
the highest rate of side effects. It is highly likely that the AstraZeneca,
Moderna and Pfizer vaccine candidates, which are along the furthest
in the US and Europe, all show sufficient efficacy and will be licensed if
sufficiently safe. However, it may also be that these vaccines will later
on be replaced by vaccines that show similar efficacy but have reactogenicity
profiles that are more tolerable. In addition, it is hard to
predict how availability and production capacity will shape the global
landscape of SARS-CoV-2 vaccines.

Krammer, F. SARS-CoV-2 vaccines in development. Nature (2020). https://doi.org/10.1038/s41586-020-2798-3
 
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bhobba said:
I know in the UK they are at least looking at doing challenge trials on the Oxford vaccine, but it is doubtful it will be done on at risk groups. It might be interesting to see what methodology they are using.

It looks like the UK is planning to go forward with challenge trials in January to compare the efficacy of various vaccine candidates:

The government said on Tuesday it will invest 33.6 million pounds ($43.5 million) in the so-called “human challenge” trials in partnership with Imperial College London, laboratory and trial services company hVIVO and the Royal Free London NHS Foundation Trust.

If approved by regulators and an ethics committee, the studies will start in January with results expected by May 2021, the government said.
https://www.reuters.com/article/uk-...e-trials-that-infect-volunteers-idUSKBN2750X9

On the methodology:
The first stage of the project will explore the feasibility of exposing healthy volunteers to the SARS-CoV-2 coronavirus. The study would recruit volunteers between the ages of 18 and 30 with no previous history or symptoms of COVID-19, no underlying health conditions and no known adverse risk factors for COVID-19, such as heart disease, diabetes or obesity.

In this initial phase, the aim will be to discover the smallest amount of virus it takes to cause a person to develop COVID-19. This is known as a virus characterisation study.

Once this first phase is completed, clinical researchers aim to use this human challenge model to study how vaccines work in the body to stop or prevent COVID-19, to look at potential treatments and study the immune response.
https://www.imperial.ac.uk/news/206893/uk-researchers-explore-human-challenge-studies/
 
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  • #23
Vanadium 50 said:
That's just goofy

It is totally goofy - as the experience with the 1976 flu vaccine proves:
https://www.smithsonianmag.com/smart-news/long-shadow-1976-swine-flu-vaccine-fiasco-180961994/

It, fortuneately, was quickly reversed - it will be voluntary. Some have recommended a staged approach - high risk first, then medium risk, then low risk. I think the rollout will depend on the effectiveness and availability of treatments at the time like the monoclonal antibody treatment Trump got.

Thanks
Bill
 
  • #24
Ygggdrasil said:
It looks like the UK is planning to go forward with challenge trials in January to compare the efficacy of various vaccine candidates

There are still those with 'true grit'.

Thanks
Bill
 
  • #25
Pfizer and BioNTech announced today interim results for the phase III trial of their mRNA vaccine, suggesting that the vaccine is 90% effective at preventing COVID-19:
PFIZER AND BIONTECH ANNOUNCE VACCINE CANDIDATE AGAINST COVID-19 ACHIEVED SUCCESS IN FIRST INTERIM ANALYSIS FROM PHASE 3 STUDY
Monday, November 09, 2020 - 06:45am

  • Vaccine candidate was found to be more than 90% effective in preventing COVID-19 in participants without evidence of prior SARS-CoV-2 infection in the first interim efficacy analysis
  • Analysis evaluated 94 confirmed cases of COVID-19 in trial participants
  • Study enrolled 43,538 participants, with 42% having diverse backgrounds, and no serious safety concerns have been observed; Safety and additional efficacy data continue to be collected
  • Submission for Emergency Use Authorization (EUA) to the U.S. Food and Drug Administration (FDA) planned for soon after the required safety milestone is achieved, which is currently expected to occur in the third week of November
  • Clinical trial to continue through to final analysis at 164 confirmed cases in order to collect further data and characterize the vaccine candidate’s performance against other study endpoints
https://www.pfizer.com/news/press-r...d-biontech-announce-vaccine-candidate-against

The actual data from the trial has not been published yet, so key information is missing, such as whether the vaccine also affects severity of disease in those who receive the vaccine and whether the vaccine prevents infection or merely prevents symptoms of the disease.

The Pfizer/BioNTech vaccine may be challenging to distribute widely as it requires two doses and the vaccine must be stored under ultra-cold conditions (< -70°C).

Here's some good summaries of the news w/ further context:
https://www.statnews.com/2020/11/09...fective-early-data-from-large-trial-indicate/
https://blogs.sciencemag.org/pipeline/archives/2020/11/09/vaccine-efficacy-data
 
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  • #26
Reuters reports that Moderna apparently claims their vaccine is 94.5% effective against coronavirus.
https://www.reuters.com/article/hea...ffective-in-preventing-covid-19-idUSKBN27W1EJ

The vaccine, like Pfizer's, is built using new technology known as messenger RNA or mRNA, represent powerful new tools to fight the SARS-COV2 virus.

A key advantage of Moderna’s vaccine is that it does not need ultra-cold storage like Pfizer’s, making it easier to distribute. Moderna expects it to be stable at standard refrigerator temperatures of 2 to 8 degrees Celsius (36 to 48°F) for 30 days and it can be stored for up to 6 months at -20 degrees Celsius.

Pfizer’s vaccine must be shipped and stored at minus 70 degrees Celsius, the sort of temperature typical of an Antarctic winter. At standard refrigerator temperatures, it can be stored for up to five days.

The data from Moderna’s 30,000 participant-strong trial also showed the vaccine prevented cases of severe COVID-19, a question that still remains with the Pfizer vaccine. Of the 95 cases in Moderna’s trial, 11 were severe and all 11 occurred among volunteers who got the placebo.
Some experts weigh in - https://www.reuters.com/article/hea...ffective-in-preventing-covid-19-idINKBN27W1FH
 
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  • #27
Oxford vaccine 90% effective, but with an interesting twist:
https://www.livescience.com/oxford-vaccine-coronavirus-efficacy.html

Here in Australia I think we have already produced enough doses for everyone in Australia, NZ, and the south pacific - probably even more with the interesting twist I will mention later. It will be deployed as soon as it is cleared. It is a conventional vaccine so does not need to be kept at low temperatures etc. Here in Aus it has passed the bar for emergency use if that is required, but at the moment Covid is very well controlled here in Aus.

Now for the interesting twist. They evidently tried two different doses. A full dose two times. A half dose first, then a full dose. The two full doses were around 62% effective, but, perhaps strangely, the half dose then a full dose was 90% effective. Evidently the suspected reason is the first dose of a vaccine can often act as a priming dose, preparing the body for the second dose. Strange, very strange.

Thanks
Bill
 
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  • #28
https://www.vox.com/21590994/oxford-vaccine-results-covid-19-astrazeneca-trial-pfizer-moderna

It's not clear whether the approximately 95% effectiveness for the Pfizer-BioNTech and Moderna vaccine, and the 70% effectiveness for the Oxford-AstraZeneca vaccine are comparable, since I don't think we know how these were measured. It seems the Moderna and Pfizer/BioNTech trials only examined symptomatic cases, while the AstraZeneca trials may include asymptomatic infections.

Also, it's not clear how many infections were used to estimate the 90% number for the Oxford-AstraZeneca vaccine.
 
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bhobba said:
Now for the interesting twist. They evidently tried two different doses. A full dose two times. A half dose first, then a full dose. The two full doses were around 62% effective, but, perhaps strangely, the half dose then a full dose was 90% effective. Evidently the suspected reason is the first dose of a vaccine can often act as a priming dose, preparing the body for the second dose. Strange, very strange.

There are a few explanation for the different data that probably more data to untangle:
1) The difference is a statistical fluke. the group receiving the half dose first is fairly small (n = 2,741) vs the group receiving the full dose first (n = 8,895), and the confidence intervals from the data are likely wide enough that they don't exclude the possibility that there is no actual difference between the two regimes.

2) The demogrpahics of those given the half dose vs the full dose are different. The group receiving the half dose was due to a mistake early in the trial, so the half-dose population was not designed to be comparable to the full dose population. In particular, Operation Warp Speed has said that the half dose population had an age cap of 55 whereas there was no age cap for the full dose group. Because vaccines are often less effective in older individuals, this difference could account for the observed difference in efficacy.

3) The half dose actually does have some "priming" benefit.

See https://blogs.sciencemag.org/pipeline/archives/2020/11/23/oxford-az-vaccine-efficacy-data for more discussion.

atyy said:
https://www.vox.com/21590994/oxford-vaccine-results-covid-19-astrazeneca-trial-pfizer-moderna

It's not clear whether the approximately 95% effectiveness for the Pfizer-BioNTech and Moderna vaccine, and the 70% effectiveness for the Oxford-AstraZeneca vaccine are comparable, since I don't think we know how these were measured. It seems the Moderna and Pfizer/BioNTech trials only examined symptomatic cases, while the AstraZeneca trials may include asymptomatic infections.

This does not appear to be the case:
Now, I’ve seen people speculating this morning that these numbers may be better than they look, because they believe that these trials monitored patients by PCR tests rather than by symptoms. If that were the case, then yes, that’s a finer net than the Pfizer and Moderna trials used and it would certainly affect the efficacy readouts. But I don’t think it is: looking at the published trial protocol for the US trial, the cases are defined as “SARS-CoV-2 RT-PCR-positive symptomatic illness”, and the patients have to show symptoms of the disease (see Table 13). Update: I have been unable to find published protocols for the UK/Brazil/South Africa trials that went into today’s numbers, but I have no reason to think that they differ on this point. So I don’t think we can explain the lower efficacy by saying that they were finding asymptomatic people as well: the trial excludes asymptomatic people from its endpoint definition. The rate of asymptomatic cases in the treatments and controls will be determined in these trials (see section 8.5.2.1 of the protocol) but those aren’t the numbers we’re seeing today.
https://blogs.sciencemag.org/pipeline/archives/2020/11/23/oxford-az-vaccine-efficacy-data

atyy said:
Also, it's not clear how many infections were used to estimate the 90% number for the Oxford-AstraZeneca vaccine.

These appear to be the numbers released by AstraZeneca and Oxford:
This interim analysis was run when 131 cases had been accrued across trials in the UK, Brazil, and South Africa across about 24,000 trial participants (treatment and control groups). In the treatment group, 8,895 participants received two full doses of the vaccine, spaced one month apart, and 2,741 patients got a half dose at first, followed by a full dose a month later. And the efficacy rates for these two dosing regimes were very different: 62% for the two-full-dose group and 90% for the half/full group.
https://blogs.sciencemag.org/pipeline/archives/2020/11/23/oxford-az-vaccine-efficacy-data
 
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  • #30
The Wall Street Journal reports that Pfizer has begun the process of shipping its COVID-19 vaccine to prepare for distribution:
United Airlines Holdings Inc. on Friday began operating charter flights to position doses of Pfizer Inc.’s Covid-19 vaccine for quick distribution if the shots are approved by regulators, according to people familiar with the matter.
https://www.wsj.com/articles/united-begins-flying-pfizers-covid-19-vaccine-11606512293

The FDA is expected to convene an outside panel of experts on Dec 10 to review evidence from Pfizer's clinical trial and vote on whether to recommend the vaccine for an emergency use authorization.

Distribution would likely guidelines established by the US National Academies of Medicine, in which high-risk healthcare workers and first responders would first receive the vaccine, followed by individuals with multiple conditions that put them at higher risk for the disease as well as people in nursing homes or similar assisted living facilities:
Capture.PNG


AFAIK, Moderna has not yet sent the FDA a request for an EUA for its vaccine, which showed similar efficacy to the Pfizer/BioNTech vaccine, though this will probably occur soon.
 
  • #31
Right now the best case scenario for the US may be a vaccine that is around 65% effective because at least 30% of Americans may not agree to get vaccinated.

TULSA, Okla. — While a vaccine for the Coronavirus is being developed, an Oklahoma State University study shows many Americans have no intention to get one.

OSU Professor Matt Motta conducted a study breaking down how many people may refuse this vaccine. He found between a third to as many as half of the nation plan to refuse a Coronavirus vaccine.
https://www.kjrh.com/news/local-news/coronavirus-vaccine-americans-predicted-to-refuse-it
 
  • #32
Currently, information for phase III clinical trials has been released for three vaccines: Pfizer-BioNTech's mRNA vaccine, Moderna's mRNA vaccine, and Oxford-AstraZeneca's adenoviral vector vaccine. All three are based on relatively new vaccine technologies. The UAE released interim analysis from the phase III clinical trial of an inactivated virus vaccine (a more traditional vaccine technology) developed by Sinopharm, showing 86% efficacy:
One of China's Coronavirus vaccines has been approved for general use by a government for the first time, with the United Arab Emirates on Wednesday endorsing a vaccine made by Sinopharm after reviewing the drugmaker's assessment that the shot was 86 percent effective.

The announcement comes as a relief for China, which has already approved widespread emergency use of the vaccine. A number of other countries, including Morocco, have pinned their hopes on Sinopharm.
Sinopharm’s efficacy rate puts the company’s vaccine behind Moderna’s 94.5 percent and Pfizer-BioNTech’s 95 percent but ahead of AstraZeneca’s 70 percent. However, data from the Phase 3 trial has not yet been released, with UAE officials giving only a few headline numbers.
https://www.washingtonpost.com/worl...2390f0-383c-11eb-aad9-8959227280c4_story.html

The inactivated virus vaccine could be more easily distributed than the mRNA vaccines as it only requires normal refridgeration for storage rather than storage in a freezer (the Moderna vaccine) or under ultracold conditions (the Pfizer-BioNTech vaccine).
 
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Likes atyy and sysprog
  • #33
Is it accurate? Thanks by the way, I appreciate it.
 
  • #34
Thanks @Ygggdrasil for your steadfast paying of attention and informing of us in this matter. I think that you have been and continue to be exceptional in passing along of insights regarding this. Thanks to everyone who's contributed to our understanding and also thanks to those who merely quietly care.
 
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Likes kith, bhobba, BillTre and 2 others
  • #35
Kind of a tangential question, but is it the case that the major vaccines will be covered by government subsidies for people to get vaccinated?

I do have health insurance (Anthem Bronze Plan), but have a $5,800 deductible.
 

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