#MSCOVID-19 Chances of making an antibody response after a COVID-19 booster Part 2. Cladribine and alemtuzumab


Yesterday I reported on the influence of ocrelizumab on B cell depletion and repoulation, today we look at other B cell depleting agents, but in contrast to ocrelizumab which hangs around for a long time, cladribine and alemtuzumab both are gone from the body within a month. So when we ask the question what happens in terms of repopulation of the B cells during therapy. What did we find?

As you know we got the oral cladribine tablet data from the European Medicines Agency many years ago. So we can again ask how long does it take to get to 1% B cells. The data is below. I could look after the second cycle but the cladribine used in the trial is not how cladribine is used in clinical practise. However, I am sure the makers of oral cladribine are on the case.

This information is based on research using data supplied by the European Medicines Agency. Data analysis, interpretation and conclusions made are independent from Merck.

We also ask long does it take B cells to repopulate with alemtuzumab. Again the manufacturers have allowed us access to the CARE-MS phase III and the extension trials and again we ask how long does it take for the B cells to get back to 1% B cells, but remember this is going to be biased as lymphocytes are being lost so really you have to look at the absolute numbers of B cells but if you look the depletion only is present for the first month

This information is based on research using data from Sanofi that has been made available through clinicalstudydatarequest.com. They have not contributed to or approved, and are not in any way responsible for, the contents of this publication. Data analysis, interpretation and conclusions made are independent from Sanofi.

So what are we seeing with regard to the vaccine response.

As you can see most people gave a response following cladribine and alemtuzumab and I suspect would be higher if Pfizer was available to all rather than use of Astrazeneca. The good response follwing vaccination in people treated with cladribine was seen in the Israeli data too.

Hope this helps you to decide when to get vaccine/booster. The full paper will arrive soon

Someone asked about the boosters and preferred choices

With the boosters in the UK only Pfizer or moderna will be used.

Comparative analysis of human immune responses following SARS-CoV-2 vaccination with BNT162b2, mRNA-1273, or Ad26.COV2.SBarbeau, D., Martin, J., Carney, E., Dougherty, E., Doyle, J., Dermody, T., Hoberman, A., Williams, J., Michaels, M., Alcorn, J., Duprex, P., McElroy, A. K.10.1101/2021.09.21.21262927 — Posted: 2021-09-23

Summary of key points We compared antigen specific humoral and T cell responses following vaccination with BNT162b2, mRNA-1273, or Ad26.COV2.S. Both mRNA based vaccines elicited higher magnitude humoral responses than Ad26.COV2.S and mRNA1273 elicited the highest magnitude of T cell response.

Ad26CoV-2 is johnson and Johnson (USA company) also known as Janssen (Belgian Subsiduary) which is like Astrazeneca.

There are other studies indicating that the induced antibody levels are abit higher with the Moderna vaccine

Disclaimer: Please note that the opinions expressed here are those of the author and do not reflect the positions of the Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust or Queen Mary Univeristy of London.

COI Multiple

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  • I got Pfizer vaccine in January and February
    Y2 cladribine April and May 2021

    July blood say lymphocytes 0.25 (Low)
    But covid antibodies c 2200 which is q high against I understand 2500 which is top protection?

    Booked covid booster for next week via super NHS link

    Am I best off to wait for October bloods to see how lymphocytes are doing (maybe also look at covid antibody level) Ie wait if lymphocytes up a bit?
    OR just get booster on Thursday anyway

    In other words i am 7 months post second covid vaccine so am I best off getting the booster ASAP regardless

  • I cannot give advice, sorry. Once antibodies are formed they have a long half life meaning the levels drop slowly and this is not therefore dependent on the lmphocyte count. In year two the T cells are depleted more than year 1 and the B cells get similarly depleted, but you are quite lymphopenic (grade 3) at 0.25. You are 3-4 months post cladribine round 2, you can read Barts Health vaccine advice.

  • Had a look at the 3.5mg/kg dosing at week 72 (second dose week 48 and 52) and all people were >10 CD19+ cells/ per microlitre but likewise none of that cohort 0.25 lymphopenia one was 0.3

  • Thank you for keeping us up to date MD1! You can post about whatever topic you like, haters be damed. I am just happy to have access to you and your teams daily thoughts. There is a global pandemic raging and many of us are still trying to understand the best path forward, so I greatly appreciate your continued COVID related posts and updates. Big Thank You!

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