[Harryg]

Just completed the Antibody test survey from Oxford Uni regarding antibody tests, a kit is sent out and instructions on how to complete. It involves a blood test and then you are given a result within 10 mins.
So I have had both vaccinations for covid one recently which was the Pfizer.
After the test was completed it showed positive for antibodies good news.
Next The better half
Test completed and shows no antibodies.Now she had the Astra Zenica jab in March still waiting for second .
Anyone else doing these surveys. They say they are not 100% but we offered anyway and sent the results off.

[CajunBMW]

Originally Posted by Harryg

Just completed the Antibody test survey from Oxford Uni regarding antibody tests, a kit is sent out and instructions on how to complete. It involves a blood test and then you are given a result within 10 mins.
So I have had both vaccinations for covid one recently which was the Pfizer.
After the test was completed it showed positive for antibodies good news.
Next The better half
Test completed and shows no antibodies.Now she had the Astra Zenica jab in March still waiting for second .
Anyone else doing these surveys. They say they are not 100% but we offered anyway and sent the results off.

These mail off tests are wildly inaccurate or perhaps better stated as having low sensitivity. My guess is the positive that you showed is real, but your better have likely had a false negative. To play devils advocate, there are a few people that could show a low response with the first dose (in this case low Antibody response) but still be protected and if given the booster or second shot, would show a much higher or better response even with these type of tests that are not very sensitive.

[Harryg]

Originally Posted by CajunBMW

These mail off tests are wildly inaccurate or perhaps better stated as having low sensitivity. My guess is the positive that you showed is real, but your better have likely had a false negative. To play devils advocate, there are a few people that could show a low response with the first dose (in this case low Antibody response) but still be protected and if given the booster or second shot, would show a much higher or better response even with these type of tests that are not very sensitive.

Thanks I thought that would be the case, its funny though during the 10 minute interval after putting the solution into the tester I could see the line changing yet I saw nothing when I did the better halfs could this not send false positives for the research anyway you have to photograph the results and fill them in online.

[isleaiw1]

Originally Posted by B58_f32

Just like the lateral flow test we are all doing are inaccurate. All chines made goods that are known to be crap

Can you provide evidence to support that (both the inaccuracy levels and that they are Chinese).

We are doing them for all staff who are in work at two tests per week and so far we have had no false positives and perhaps more importantly we have had no one go down with the virus that has tested negative.

So the lateral flow tests WE are doing have not been crap.

[isleaiw1]

Originally Posted by B58_f32

https://www.express.co.uk/news/uk/14...-China-Twitter

lots of articles online, dont trust the originators of the virus

Well its in the Express and doesnt say the tests are inaccurate... apart from that its great...

I'll stick with my own evidence that we are happy with the results we are obtaining - even if the cost of them is a ballache and the NHS system for suppliers employers was a nightmare and now you cant get them if you were registered before a certain date (which we were but somehow they lost!)

[Nibbles]

Originally Posted by B58_f32

There is lies on both sides to do with this Imported virus, The government lie about a few things, media and some newspapers.

People just have to get on with it really. Im waiting for matt wanc ock to invent the Eastenders strain on june 20th to push us all back into lockdown.

I know a few people who tested negative on lateral flow and positive on PCR after.

I didn't realise there were sides in a global pandemic other than humans vs virus?

[PeakyJ]

Originally Posted by isleaiw1

Can you provide evidence to support that (both the inaccuracy levels and that they are Chinese).

We are doing them for all staff who are in work at two tests per week and so far we have had no false positives and perhaps more importantly we have had no one go down with the virus that has tested negative.

So the lateral flow tests WE are doing have not been crap.

I read somewhere that the lateral flow tests are fairly accurate if you have a high viral load so theoretically good for catching potential super spreaders at least.

Personally I think they are worth doing.

[isleaiw1]

Originally Posted by PeakyJ

I read somewhere that the lateral flow tests are fairly accurate if you have a high viral load so theoretically good for catching potential super spreaders at least.

Personally I think they are worth doing.

And normally if anything they would give a false positive not a false negative - so I am a fan.

[isleaiw1]

Originally Posted by B58_f32

There is lies on both sides to do with this Imported virus, The government lie about a few things, media and some newspapers.

People just have to get on with it really. Im waiting for matt wanc ock to invent the Eastenders strain on june 20th to push us all back into lockdown.

I know a few people who tested negative on lateral flow and positive on PCR after.

Lots of lies from uninformed people spreading malicious gossip on social media and internet forums too....

[Harryg]

Originally Posted by B58_f32

Just like the lateral flow test we are all doing are inaccurate. All chines made goods that are known to be crap

Sorry cant believe that these kits come complete with tester etc, I imagine you could get false readings by people doing them wrong but to be in a trial and the amount that is taking part they must have worked these percentages out and get some good feedback on the state of the population. As the kits come complete and are delivered to your home there must be a cost so I really cannot see Oxford doing all of this if the results were all inaccurate fair enough I have antibodies my wife hasn't it doesn't mean these tests are not worth doing we will be receiving them again shortly once the wife has had her second jab and will see what the outcome is. Oxford are harvesting all of this information so there is a good reason behind it. They have done a great job in getting a vaccine so if by participating in one of their surveys helps them its a small price to pay.

[CajunBMW]

Originally Posted by Harryg

Thanks I thought that would be the case, its funny though during the 10 minute interval after putting the solution into the tester I could see the line changing yet I saw nothing when I did the better halfs could this not send false positives for the research anyway you have to photograph the results and fill them in online.

In the end, one worries about the false positive and false negative rates of any diagnostic assay. Obviously a lot goes into designing good diagnostics assays with high sensitivity and low rates of errors. PCR is a good example of a diagnostic assay that checks all the boxes. In general, with great sensitivity you bias towards false positives. A good example is the high quality PCR assays used for detecting CoV genomic material (and other things as well of course). They are so sensitive that near the lower limit of detection it is easy to see very very weak positives (that could be a false positive). Now the good folks that work in these places have a cut off and procedures in place to deal with this issue. You get very few false negatives in this manner.

The best lab procedures for testing antibody levels are also very sensitive and the point above holds true with those too type of lab diagnostic antibody assays.

Now with these other types of diagnostic kits such as the one you described above, they are by nature less sensitive. It doesn't necessarily make them bad, it just means they have lower sensitivity and because they are designed to be quick and easy to use that is their liability. Now there were lots of cheap and poor diagnostic kits that came on the market early in the pandemic that just didn't really work. I am hoping most of those are not in use and what you get now are kits designed to tell you if have something and it does so by detecting a high level of what ever it is you are looking for.

I hope this makes sense.

Cheers,

[CajunBMW]

Originally Posted by isleaiw1

Can you provide evidence to support that (both the inaccuracy levels and that they are Chinese).

We are doing them for all staff who are in work at two tests per week and so far we have had no false positives and perhaps more importantly we have had no one go down with the virus that has tested negative.

So the lateral flow tests WE are doing have not been crap.

Lateral flow kits work fine. You are correct most in use work well and are to be trusted. As I pointed out in another response, the only real limitation of a point of care test is a bit lower sensitivity vs that seen with a longer and more complex laboratory directed assay. We use point of care tests a lot and trust them for what they are designed to do. They give you an answer quickly and work. Yes those with lower levels of virus or antibody might be missed but that per se is not due to a bad kit, but the limit of getting a quick answer.

Cheers,

[CajunBMW]

Originally Posted by Nibbles

I didn't realise there were sides in a global pandemic other than humans vs virus?

In theory humans and animals vs virus. These darn coronaviruses infect and can harm most mammals and many birds too.

[CajunBMW]

Originally Posted by PeakyJ

I read somewhere that the lateral flow tests are fairly accurate if you have a high viral load so theoretically good for catching potential super spreaders at least.

Personally I think they are worth doing.

Exactly. That is completely true. That is my point above in another response. We have for the CoV tested many of these side by side with PCR and thus could compare viral load detected from the same person.