Antibody test after vaccine

[davidinharrow]

My wife has CLL and has been on watch and wait for the past 4 years. She is “lucky” that the regular tests always come back with no additional treatment.

After having her first Astra Zenica vaccine in Feb she took an antibody test 6 weeks after and it returned negative (both lorraine and myself are enrolled in a UCL covid study) . Naturally she was disapointed, month went by and 2nd blood test came she completed it and to her delight it came back posative. That was also before the booster dose of AZ. Took anther test this week and are waiting for results. So hopefully it has given some protection even though it took a long time to kick in. This may give some vallidation on the theory that a wider wait between first and second vaccination gives a better imune response.

Sorry about my spelling mistakes

[Ptcad]

Alas I had no antibody response either after one dose - you might want to read a post on CLL and vaccines I’ve just posted. We’re going to be relying on our T cell response not antibodies by the looks of things!

[Everest8848]

Hi davidinharrow,

I'm new to this community, but reading your post about the increasing antibody response over time is very exciting and positive news!!

The only paper I have found so far specifically related to vaccine response in CLL patients is the paper by Mounzer Agha et al. ( medrxiv.org/content/10.1101... ) which has been referred to elsewhere in this thread. This study had only 13 patients in the CLL cohort, and the antibody tests were done a median time of 23 days after the 2nd Pfizer jab. As the study was done in the USA, I assume 3-4 weeks between doses, so around 6-7 weeks since the first jab. Only 3 out of the 13 patients got a "positive" response during this time frame; the rest were "negative". This study did not look at changes in antibody response over time, which based on your experience could be very significant. Furthermore the antibody measurements were only semi-quantitative, whereas fully quantitative measurements are now available and could give more granularity to the results.

I will be very interested to see the eventual results of the UCL study you are enrolled in. Would you be able to you provide any further details of the study or a link to it? I would be quite happy to enroll in the study if they are still recruiting.

I got my first Pfizer jab 6 weeks ago, and being very concerned about my level of protection, I privately got a quantitative spike RBD (receptor binding domain) IgG antibody test done 30 days after the jab. The result was 19 AU/ml and was classified as "negative", with a cut-off of 50 AU/ml for a positive result. Based on published data in one study (J. Ebinger et al. in Nature Medicine, nature.com/articles/s41591-... ), a normal response to a first Pfizer jab would be in the range of 100's - 1,000's AU (Median 1,100), and my outcome was in the bottom 1%. However, although weak, my antibody response was significantly higher than the baseline of unvaccinated people in the study. So I would consider this to be the first seeds of positive response. Although classified as a "negative" result, in the context of CLL I would consider it to be a "positive" result, and this illustrates the importance of getting a fully quantitative rather than a semi-quantitative test. My result is actually similar to the expected response of a healthy person when given a very weak dose of Pfizer (1microgam, instead of the now standard 30 micrograms), (see U. Sahin et al. medrxiv.org/content/10.1101... ) and this may reflect the fact that >90% of the injected vaccine is interacting with, and being wasted on inactive cancerous B-cells, and only a small proportion of the 30 microgram dose I received reaches an active working B-lymphocyte. [Disclaimer - this thought is pure speculation and is not based on any medical evidence whatsoever]. I get my second Pfizer jab tomorrow (yipee!!) and will follow-up with a further quantitative antibody test after about 3 weeks. Based on your results I now plan to additional tests to see if there is further improvement over time, and I will share the results on this site.

Please keep us updated on your results, and especially how the antibody response progresses after your second AZ jab. Good luck and stay safe!!