Antibody test, optimal timing

[BART4]

hi from Poland I have been on Zanubrutinib (small molecule inhibitor of Bruton's tyrosine kinase) for three years. I had a moderna booster two weeks ago. I wonder after how long to do the antibody test. I called 5 different labs and they suggested doing a blood test over a period of two weeks to six weeks. each lab has a different date. what are your experiences. thank you for your answers

[bennevisplace]

Hi Bart4.

If you can, find a lab that uses a reputable test. Many of our members in the USA and in the UK have taken the Elecsys Anti-SARS-CoV-2 S semi-quantitative test diagnostics.roche.com/gb/en... and you will find a number of posts reporting their test results in numbers. You will find very few on active treatment with a BTK inhibitor who reported a positive result (>0.8 units on this test), but good luck.

In the above web-link you will find a table, giving a claimed test sensitivity of practically 100 % after 28 days, but this would have been measured on immunocompetent subjects. I would suggest waiting 6 weeks minimum before doing the test. The waning of antibody levels (if any) will be much more gradual than the build-up, so if anything err on the long side.

IMO, and I have no medical training.

[LeoPa]

Hi greetings from Slovakia 😄. My wife had the third vaccine and two weeks later the lab where she works did the antibody test. She and her colleagues saw a tremendous rise in the antibodies in their bloods. THEY ARE CHOCK FULL OF ANTIBODIES YOU COULD SAY 😁 None of them has CLL though.

[LeoPa]

I forgot to add that they did a t-cell immunity test too. There were no specific figures provided but the results say that they all have vaccine induced t cell immunity against covid as well.