COVID-19: Vaccine/antidote and testing procedures Megathread [Mod Warning - Post #1]

irishgeo

ACitizenErased wrote: »

Great interview with Sarah Gilbert who is leading the UofOxford vaccine.

Covid Vaccine Front-Runner Is Months Ahead of Her Competition

The University of Oxford candidate, led by Sarah Gilbert, might be through human trials in September. AstraZeneca has lined up agreements to produce 2 billion doses. Could this be the one?

https://www.bloomberg.com/news/features/2020-07-15/oxford-s-covid-19-vaccine-is-the-coronavirus-front-runner?cmpid=socialflow-twitter-businessweek&utm_content=businessweek&utm_campaign=socialflow-organic&utm_medium=social&utm_source=twitter

They had some of the work done as they were working a mers vaccine and tweaked it for covid. Hopefully we will see this vaccine work and then we will learn lessons from it all.

darjeeling

Yesterday's TWiV (This Week in Virology) has a good and important discussion on testing, based around a couple of papers.

The idea is basically that cheap, fast, mass-scale testing of schools, colleges, workplaces can be used to stop the virus spreading before new outbreaks can appear.

The current real-time rtPCR tests are highly sensitive but must be carried out in a lab by a trained technician using a real-time PCR machine.
This limits testing to people with symptoms or their close contacts, so we can't do the regular mass screening that would allow us to go back to relatively normal life.

A cheap, rapid and simple test for virus would allow mass testing on a scale not currently possible.
Paper strip tests using monoclonal antibodies against the virus are likely to be the best way to do this, and multiple companies and university labs have been working on developing these tests.
However, these tests have been criticised for being less sensitive than rtPCR tests.

In the TWiV interview discussing his paper, author Michael Mina explains why the claimed lack of sensitivity is a red herring.

Viral load rises very rapidly in the first few days of infection, but it then takes a long time for viral RNA to disappear.
Studies show that people are infectious for the first few days when viral RNA levels are high. The rapid tests actually perform well in identifying these people.

Viral RNA can still be detected by rtPCR at very low levels weeks later, even when people have long ceased being infectious because they are no longer shedding active virus.
(NB - the really useful quantitative Ct value of the rtPCR test is usually overlooked, and instead the result is treated as binary: presence or absence of viral RNA)
It's at this point that rapid tests may give a negative result whereas rtPCR shows positive. But this doesn't matter because people at this point are not going to infect anyone.
Indeed, a negative test is arguably beneficial as it avoids wasting contact tracing resources on people who are no longer infectious.

The podcast also has a discussion of pooled sample testing and its application to detection of outbreaks rather than individuals, again allowing appropriate allocation of resources and more intensive testing when a new outbreak is seen.

If you've not discovered TWiV, it's probably one of the best places to get informed expert discussion of pretty much every aspect of the virus, with regular interviews with leading scientists and public health experts. Though maybe at 1 1/2 to 2 hrs per episode you might not want to be quite that informed.

amadangomor

I has suspected Covid19 back in March/April. Tempted to go for an antibody test.

Anyone use this company

https://www.cerascreen.ie/products/coronavirus-antibody-test?gclid=EAIaIQobChMI1rPvn9PR6gIV0oBQBh22ygqQEAAYASAAEgJmIvD_BwE

Gael23

Can we realistically expect mass rollout Of the Oxford vaccine by September?

stevek93

amadangomor wrote: »

I has suspected Covid19 back in March/April. Tempted to go for an antibody test.

Anyone use this company

https://www.cerascreen.ie/products/coronavirus-antibody-test?gclid=EAIaIQobChMI1rPvn9PR6gIV0oBQBh22ygqQEAAYASAAEgJmIvD_BwE

Home test kits are useless from what I heard.

Santy2015

Is this realistically possible??
https://news.sky.com/story/coronavirus-oxford-vaccine-could-provide-double-protection-report-12029406

hmmm

Gael23 wrote: »

Can we realistically expect mass rollout Of the Oxford vaccine by September?

I think that's too optimistic. Absolute best case for mass rollout is late 2020, early 2021 - and that assumes everything goes well during the trials. Some doses may become available to certain groups earlier e.g. medical staff.

I suspect the world will change quite quickly however when we know we have a successful vaccine and it is being manufactured. I think the uncertainty is hurting everyone. The government will be more inclined to borrow and spend to bridge the gap and keep businesses alive, and it'll be easier to ask people to take care and protect themselves.

Stark

They started mass manufacturing the thing earlier in the year so once it does get approval, there should be a decent stock of it ready to go.

stevek93

Stark wrote: »

They started mass manufacturing the thing earlier in the year so once it does get approval, there should be a decent stock of it ready to go.

Yes, I also saw that, do we know how much?

Hmmzis

Santy2015 wrote: »

Is this realistically possible??
https://news.sky.com/story/coronavirus-oxford-vaccine-could-provide-double-protection-report-12029406

Any part in particular from that article you're curious about?
If it's the dates, then, well, they're in phase III now, we just have to wait and see when they get sufficient data to tell if and how effective it is.
If it's the T cell response, that would be the norm for a good vaccine, the immune system isn't just about antibodies.

is_that_so

Not quite vaccine related but it does raise some interesting ideas about COVID-19 research in general.

More than 2,000 COVID-19 clinical trials have been registered around the world. At least 90% are in wealthy nations, most looking at treatments in hospitals. These studies are needed, and the speed and collaboration involved have been amazing. But we must mind the gaps.

https://www.nature.com/articles/d41586-020-02004-1

Martina1991

darjeeling wrote: »

Yesterday's has a good and important discussion on testing, based around a couple of papers.

The idea is basically that cheap, fast, mass-scale testing of schools, colleges, workplaces can be used to stop the virus spreading before new outbreaks can appear.

The current real-time rtPCR tests are highly sensitive but must be carried out in a lab by a trained technician using a real-time PCR machine.
This limits testing to people with symptoms or their close contacts, so we can't do the regular mass screening that would allow us to go back to relatively normal life.

A cheap, rapid and simple test for virus would allow mass testing on a scale not currently possible.
Paper strip tests using monoclonal antibodies against the virus are likely to be the best way to do this, and multiple companies and university labs have been working on developing these tests.
However, these tests have been criticised for being less sensitive than rtPCR tests.

Viral load rises very rapidly in the first few days of infection, but it then takes a long time for viral RNA to disappear.
Studies show that people are infectious for the first few days when viral RNA levels are high. The rapid tests actually perform well in identifying these people.

Viral RNA can still be detected by rtPCR at very low levels weeks later, even when people have long ceased being infectious because they are no longer shedding active virus.
(NB - the really useful quantitative Ct value of the rtPCR test is usually overlooked, and instead the result is treated as binary: presence or absence of viral RNA)

When I read the line "why frequent and rapid SARS-CoV-2 testing is more important than accuracy" I tuned out.

A slow result or even no result is better than a wrong result.

Test strips are not an accurate measure to detect the presence of the virus or antibodies. A faded line or slight colour change on a paper strip is completely ambiguous.

In an ideal world everyone wants tests to be cheap, quick and accurate.
The reality when it comes to testing like this is, you can only choose 2 out of the 3.

tobefrank321

I know this isn't going to go down well, but were any of the 45 participants in the Moderna trial subsequently exposed to or infected with covid 19?

They also appear to have been in the low risk age group of 18-55 with relatively strong immune systems. What happens when you give the vaccine to someone with a weak immune system or other complications?

Stark

Martina1991 wrote:

When I read the line "why frequent and rapid SARS-CoV-2 testing is more important than accuracy" I tuned out.

A slow result or even no result is better than a wrong result.

Test strips are not an accurate measure to detect the presence of the virus or antibodies. A faded line or slight colour change on a paper strip is completely ambiguous.

In an ideal world everyone wants tests to be cheap, quick and accurate.
The reality when it comes to testing like this is, you can only choose 2 out of the 3.

A quick but less accurate test could be used to expand the net of people being tested and a follow up more accurate test can be arranged for those who test positive. Anyone who is in a suspected category and would have been tested using the more accurate method to begin with should continue to be tested as such.

There's a rapid test for HIV which is less accurate than lab tests but allows for a much larger reach for testing. (I've seen popup rapid HIV test clinics at pubs and events for example). Any positive cases are then referred for lab tests. It's been hugely beneficial.

It sounds like the rapid test for coronavirus would be most sensitive during the pre-symptomatic highly infectious period (where people would often be overlooked for rtPCR tests as they haven't developed symptoms yet) which is the ideal time for mass scale rapid testing.

Gael23

In which country will this AstraZeneca vaccine be produced?

darjeeling

Martina1991 wrote: »

When I read the line "why frequent and rapid SARS-CoV-2 testing is more important than accuracy" I tuned out.

A slow result or even no result is better than a wrong result.

Test strips are not an accurate measure to detect the presence of the virus or antibodies. A faded line or slight colour change on a paper strip is completely ambiguous.

In an ideal world everyone wants tests to be cheap, quick and accurate.
The reality when it comes to testing like this is, you can only choose 2 out of the 3.

You read a headline that a podcast host used to describe a paper, not anything in the paper itself.
And if you listen to the interview or read the paper, what you're suggesting is a 'wrong' result where a PCR test would differ from a rapid test is most likely to happen when someone has very low levels of residual viral RNA and is not infectious. So not really a wrong result if you 're interested in whether someone is infectious.

The whole point of the argument is that rapid tests can give good enough accuracy for detection of people who are infectious.
That allows for mass, regular repeated screening that is not possible with the limited testing capacity of centralised labs.
There is no other way to do weekly screening, say, of every pupil in every school, or every college student, or everyone in a workplace.

Anyone testing positive could then be referred for a more accurate clinical test that would be used for their treatment.

hmmm

Gael23 wrote: »

In which country will this AstraZeneca vaccine be produced?

They've signed a couple of deals, the only one I know off the top of my head is the Serum institute of India. They're worried about scaling manufacturing, but also they don't want manufacturing all concentrated in one country because of the obvious risk that country simply keeps all the vaccines produced. That's a realistic risk, particularly in the US.

irishgeo

hmmm wrote: »

They've signed a couple of deals, the only one I know off the top of my head is the Serum institute of India. They're worried about scaling manufacturing, but also they don't want manufacturing all concentrated in one country because of the obvious risk that country simply keeps all the vaccines produced. That's a realistic risk, particularly in the US.

Never mind the US keeping the vaccine made in their own country you have stop them buying/stealing anyone else's.

Martina1991

Stark wrote:

A quick but less accurate test could be used to expand the net of people being tested and a follow up more accurate test can be arranged for those who test positive. Anyone who is in a suspected category and would have been tested using the more accurate method to begin with should continue to be tested as such.

There's a rapid test for HIV which is less accurate than lab tests but allows for a much larger reach for testing. (I've seen popup rapid HIV test clinics at pubs and events for example). Any positive cases are then referred for lab tests. It's been hugely beneficial.

The problem is having a high percentage of false negatives. Positive results can go on to be confirmed. Having a load of false negatives is what will do the damage.

Even to have a rapid HIV test, an incubation period of at least 6 weeks needs to elapse for antobodies to develop. Thats a long time to wait in the context of Covid. HIV is also blood borne and is far less likely to be transmitted if using contraception. Covid19 is far more contagious and can effect anyone.

I just dont think we should compromise accuracy for quick cheap results.

Martina1991

darjeeling wrote:

The whole point of the argument is that rapid tests can give good enough accuracy for detection of people who are infectious. That allows for mass, regular repeated screening that is not possible with the limited testing capacity of centralised labs. There is no other way to do weekly screening, say, of every pupil in every school, or every college student, or everyone in a workplace.

What would define 'good enough' though.

Is there even a need for mass testing of every single child, student and workplace when the virus is kept contained, tracked and traced.

Conducting hundreds of thousands of rapid tests would still cost a fotune. Applicable to airports, maybe. To do it repeatedly on the entire population sounds like overkill.

gmisk

ACitizenErased wrote: »

PFIZER AND BIONTECH GRANTED FDA FAST TRACK DESIGNATION FOR TWO INVESTIGATIONAL MRNA-BASED VACCINE CANDIDATES AGAINST SARS-COV-2

https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-granted-fda-fast-track-designation-two

Could be ready in as little as 4 months. Mad that Pfizers may beat out Moderna.

I talked to a friend a few days ago....Pfizer look like best bet....they are buying a lot of kit for storage etc

Gael23

irishgeo wrote: »

Never mind the US keeping the vaccine made in their own country you have stop them buying/stealing anyone else's.

Any ethical company won’t cut a deal with them. Stealing is another matter
Is there any possible mechanism to ensure equitable distribution and that a small country like ours gets any?

Holly004

Could anyone tell me if test results are given out over the weekend?

Thank you.

JeffKenna

I got mine on a Saturday anyway.

Holly004

JeffKenna wrote: »

I got mine on a Saturday anyway.

Thanks for that. By any chance were you tested in the Aviva stadium? If so what entrance did you use? My friend had an appointment there today but missed it because she got lost.

Thanks so much.

wheresthebeef

Holly004 wrote: »

Could anyone tell me if test results are given out over the weekend?

Thank you.

They are indeed. Negative by text message, positives by means of a phone call.

Beasty

Threads merged

hmmm

Wow, Oxford and others are going for challenge trials.

"Coronavirus vaccine: Oxford team aim to start lab-controlled human trials"

https://www.theguardian.com/science/2020/jul/16/coronavirus-vaccine-oxford-team-volunteers-lab-controlled-human-challenge-trial

darjeeling

Martina1991 wrote: »

What would define 'good enough' though.

Is there even a need for mass testing of every single child, student and workplace when the virus is kept contained, tracked and traced.

Conducting hundreds of thousands of rapid tests would still cost a fotune. Applicable to airports, maybe. To do it repeatedly on the entire population sounds like overkill.

We're getting good evidence from around the world of just how quickly new outbreaks can become established when there is no screening.

Singapore looked to be doing very well until they discovered that the virus was spreading in migrant worker hostels on the outskirts of the city, and they've since been battling with tens of thousands of cases.
Israel successfully contained the first wave of the virus, then reopened the economy and is now experiencing an even bigger second wave.
The last few weeks and days have seen new outbreaks and local lockdowns in Germany and Spain.
Cheap, rapid mass screening of asymptomatic people could help us avoid this.


Note that we're talking here about mass screening of asymptomatic people, not clinical testing for people who have presented with symptoms. The test used needs to be appropriate to the situation, and obviously that includes being practically possible.


The modelling in the main paper discussed considers effects of testing frequency and delay to results reporting for high and low sensitivity tests in either a large semi-enclosed population like a college campus, or an entire city the size of New York.

Results show that twice-weekly screening of everyone in either population can reduce the number of infections to close to zero, regardless of whether the test used is a super-sensitive rtPCR test or a rapid test with a 100x lower viral RNA sensitivity threshold.

Testing only weekly with the lower sensitivity test sees infections cut by over 60% in both populations.

With the high sensitivity test, assuming results are returned the same day, infections are cut by over 80% in the college model, over 95% in the city-wide model.
But if you have to wait even one day for results, then the high sensitivity test is actually less effective than a low sensitivity same-day test.

It's become obvious that we don't have the centralised lab testing capacity for regular screening of very large numbers of asymptomatic people using rtPCR tests.
So you then have a choice between not doing mass screening of asymptomatic people so that infections run unchecked until the first symptomatic cases appear and are tested, by which time a new outbreak can be well established, or you find ways to administer a cheap, rapid on-site test.

Hmmzis

hmmm wrote: »

Wow, Oxford and others are going for challenge trials.

"Coronavirus vaccine: Oxford team aim to start lab-controlled human trials"

https://www.theguardian.com/science/2020/jul/16/coronavirus-vaccine-oxford-team-volunteers-lab-controlled-human-challenge-trial

To me it reads more like a backup option, in case they don't get a robust enough signal by end of Summer.