Thank you Alex. I am curious if you have an opinion about Memory T-cell tests such as the "T-Detect" as a more accurate/reliable surrogate to indicate the possibility of actual immunity? https://www.t-detect.com/ Thank you.
Hi, John. Certainly a cell-mediated test would be better than the facile stupidity of simply measuring antibodies, which is only done because it is easy, cheap, measurable and leveragable for convicing people that they need another injection/"booster." I don't know about that particular test that you mentioned, and they have blocked access from abroad so I cannot see their data.
Thank you. If you are interested, here are the 4 reference links that the test vendor touts on their website. Here in USA (most states) folks can order and do this test for about $129 bucks. It is also under an FDA EUA, just like the vaccines. I went and did it in the early spring for kicks and giggles. (I was negative, sadly lol).
-Zuo J, et al. Robust SARS-CoV-2-specific T-cell immunity is maintained at six months following primary infection. bioRxiv. 2020.
-Adaptive data on file
-Ng, O, et al. Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection. Vaccine. 2016.
-Dalai, S, et al. Clinical Validation of a Novel T-Cell Receptor Sequencing Assay for Identification of Recent or Prior SARS-CoV-2 Infection. medRxiv. 2020.
Very much appreciate your way of looking at and analyzing data, Alex. Please refer me to any info that contradicts the following opinion as I'm eager to learn: In this specific case, from everything I can find, the FDA's primary reason for authorizing the vaccines was because of a very large drop in infections in people randomized to vaccines vs. those randomized to placebo. This was true with adults and later in a clinical trial with children down to age 12. To authorize (let alone approve) a vaccine based primarily on the presence of antibodies the FDA would first need to see extremely strong evidence that antibodies and protection from infection were very highly and consistently associated. The FDA clearly doesn't have that kind of evidence yet - hence their advisory. It would be great, as commenter Collins wonders, if there WAS a valid marker (like T cells, etc) because it would accelerate vaccine development and approval. Hope scientists are working on that but we definitely need to know more about how well the vaccines work, with what kinds of clinical scenarios, etc. That takes big secure data and deep cooperation among patients, clinicians, policy people, scientists, etc. Thank you for keeping us thinking!
Iver, just to be clear. The studies that were done/are being done (at least when referring to Pfizer and Moderna vaccines used in USA) did NOT/do NOT show a "very large drop in infections" in vaccine group (vs placebo group). How do we know this? Because the researchers did NOT test the subjects in either group (for presence of infection) UNLESS/UNTIL they expressed symptoms of covid-19. Only after reporting symptoms, was a participant tested. So all study participants with no symptoms were never tested (which was the vast majority of test subjects). The study was NOT / is NOT designed to determine if the vaccines decrease infection (nor transmission) with SarsCov-2, but rather to determine if the vaccines decrease SYMPTOMATIC infection/symptomatic illness caused by the virus, aka Covid-19 disease.
Thank you John - I will definitely look at these references! It seems you're saying that the clinical trials found a large drop in SYMPTOMATIC infections but were not set up to find out whether there was a difference in infections (=symptomatic + asymptomatic). Odd they would set up a trial that way since people can transmit the disease when asymptomatic. Though possibly it would have been difficult to test people frequently to see if their PCR turned positive. Perhaps the NEJM papers or editorial commentary will help illuminate that question....
Thank you Alex. I am curious if you have an opinion about Memory T-cell tests such as the "T-Detect" as a more accurate/reliable surrogate to indicate the possibility of actual immunity? https://www.t-detect.com/ Thank you.
Hi, John. Certainly a cell-mediated test would be better than the facile stupidity of simply measuring antibodies, which is only done because it is easy, cheap, measurable and leveragable for convicing people that they need another injection/"booster." I don't know about that particular test that you mentioned, and they have blocked access from abroad so I cannot see their data.
Thank you. If you are interested, here are the 4 reference links that the test vendor touts on their website. Here in USA (most states) folks can order and do this test for about $129 bucks. It is also under an FDA EUA, just like the vaccines. I went and did it in the early spring for kicks and giggles. (I was negative, sadly lol).
-Zuo J, et al. Robust SARS-CoV-2-specific T-cell immunity is maintained at six months following primary infection. bioRxiv. 2020.
-Adaptive data on file
-Ng, O, et al. Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection. Vaccine. 2016.
-Dalai, S, et al. Clinical Validation of a Novel T-Cell Receptor Sequencing Assay for Identification of Recent or Prior SARS-CoV-2 Infection. medRxiv. 2020.
Very important information. Thank you.
Very much appreciate your way of looking at and analyzing data, Alex. Please refer me to any info that contradicts the following opinion as I'm eager to learn: In this specific case, from everything I can find, the FDA's primary reason for authorizing the vaccines was because of a very large drop in infections in people randomized to vaccines vs. those randomized to placebo. This was true with adults and later in a clinical trial with children down to age 12. To authorize (let alone approve) a vaccine based primarily on the presence of antibodies the FDA would first need to see extremely strong evidence that antibodies and protection from infection were very highly and consistently associated. The FDA clearly doesn't have that kind of evidence yet - hence their advisory. It would be great, as commenter Collins wonders, if there WAS a valid marker (like T cells, etc) because it would accelerate vaccine development and approval. Hope scientists are working on that but we definitely need to know more about how well the vaccines work, with what kinds of clinical scenarios, etc. That takes big secure data and deep cooperation among patients, clinicians, policy people, scientists, etc. Thank you for keeping us thinking!
Iver, just to be clear. The studies that were done/are being done (at least when referring to Pfizer and Moderna vaccines used in USA) did NOT/do NOT show a "very large drop in infections" in vaccine group (vs placebo group). How do we know this? Because the researchers did NOT test the subjects in either group (for presence of infection) UNLESS/UNTIL they expressed symptoms of covid-19. Only after reporting symptoms, was a participant tested. So all study participants with no symptoms were never tested (which was the vast majority of test subjects). The study was NOT / is NOT designed to determine if the vaccines decrease infection (nor transmission) with SarsCov-2, but rather to determine if the vaccines decrease SYMPTOMATIC infection/symptomatic illness caused by the virus, aka Covid-19 disease.
pfizer: https://www.nejm.org/doi/full/10.1056/NEJMoa2034577?query=WB
moderna: https://www.nejm.org/doi/full/10.1056/NEJMoa2035389?query=TOC
Thank you John - I will definitely look at these references! It seems you're saying that the clinical trials found a large drop in SYMPTOMATIC infections but were not set up to find out whether there was a difference in infections (=symptomatic + asymptomatic). Odd they would set up a trial that way since people can transmit the disease when asymptomatic. Though possibly it would have been difficult to test people frequently to see if their PCR turned positive. Perhaps the NEJM papers or editorial commentary will help illuminate that question....