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.
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
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.