Guest Post: Oliver Findling. Limited seroconversion after third COVID-19 vaccine dose in CD20-treated individuals


“We know that patients on CD20 depleting treatment have a higher risk of a more severe Covid 19 course and that the humoral (antibody) immune response in these patients is reduced after vaccination, so there is probably reduced protection. Now, our data from Switzerland show that CD20-depleted patients who did not respond to the first two vaccinations hardly develop any antibodies even after the third vaccination. It may be that the infusion interval needs to be spread to improve the antibody response.”

Oliver Findling

Lutz Achtnichts, Barbara Jakopp,Michael Oberle ,Krassen Nedeltchev ,Christoph Andreas Fux ,Johann Sellner and Oliver Findling Humoral Immune Response after the Third SARS-CoV-2 mRNA Vaccination in CD20 Depleted People with Multiple Sclerosis. Vaccines 20219(12), 1470;,

CD20 depletion is a risk factor for unfavorable outcomes of COVID-19 in people with MS (pwMS). Evidence suggests that protective IgG response to mRNA-based vaccines in B cell-depleted individuals is limited. We studied the seroconversion after the third mRNA SARS-CoV-2 vaccine in B cell-depleted pwMS with limited or no IgG response after the standard immunization. Sixteen pwMS treated with ocrelizumab or rituximab received a third homologous SARS-CoV-2 mRNA vaccine, either the Moderna mRNA-1273 or Pfizer-BioNTech’s BNT162b2 vaccine. We quantified the response of IgG antibodies against the spike receptor-binding domain of SARS-CoV-2 four weeks later. An antibody titer of 100 AU/mL or more was considered clinically relevant. The median time between the last infusion of the anti-CD20 treatment and the third vaccination was 22.9 weeks (range 15.1–31.3). After the third vaccination, one out of 16 patients showed an IgG titer deemed clinically relevant. Only the seroconverted patient had measurable B-cell counts at the time of the third vaccination. The development of a humoral immune response remains rare in pwMS on anti-CD20 therapy, even after third dose of the homologous SARS-CoV-2 mRNA vaccine. It remains to be determined whether T-cell responses can compensate for the lack of seroconversion and provide sufficient protection against CoV-2 infections

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Disclaimer: 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 or the University of Basel

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The MS Bloggger


  • I don’t see how these results are much different from previous data on B cell lymphoma patients receiving rituximab. These patients did not seroconvert when vaccinated against influenza or others. There are papers from many years showing that blunted ab response was ameliorated by cellular immunity /T cell response. MS patients on CD 20 depleting agents show a similar response to SARS Cov-2 vaccines.

    • They are not different…I have given you that information and and said what was coming your way. The writing was on the wall months ago. I agree the blunted vaccine responses where predictable…So what has been done about it?
      This is more data that shows this, because strangely in some academic’s eyes the data does exist until it is shown, as before this it is spectulation which as we know is garlic/holy water of scientics compared to Vampires.

      As such we waste the opportunity to do a study to do something about it. Because i can already guess the forth booster shot is not going to make much of a difference to those dont respond to the third. This study has been done in a non-MS condition. The manufacturers of all the different DMT should have been on the ball and looked at ways to try and determine if responses can be made. Most have dodged the bullet and have faired perhpas even better than feared.

      We know there is a real problem with anti-CD20, so what have the three companies done to mitigate this….nothing evident so far, and fingolimod and possibly siponimod, ozanimod and ponesimod, so what have the three companies done so far….nothing useful reported. In the arthritis field there was a problem with methorexate…I have see two studies where there was a transient halt verses standard therapy and a response was made. Is there are a unified approach to address this in MS?

      It is obvious to anyone who can read that based on the label, the standard dosing is going to stop many people responding. A delay is an option but how long and how safe and this is where the manufacturers should have provided an answer months ago becuase people will trust the data if the manufactureres do it, but the boosters have now probably been wasted as has a chance to do something. We will now see a flurry of papers replicating this study.

      It is easier to do nothing and Neuros may say (rightly?) the T cell response will be boosted. It may do but people on anti-CD20 depleters will be catching COVID and some people are being hospitalized. (Get well soon!)….but it seems stick to the lable as MS is worse than COVID-19 and for the demographic I would agree with this in most cases. Then they may have thought you can use our antibody as an anti-viral if you catch covid, so two sales…Ker-king…but sad to say that idea is out the window with omicron, as it looks like it doesn’t work on omicron. I know of a twenty something female who got their booster at the beginning of the month (anti-body levels should be up within a week) two weeks later they have COVID-19. (omicon). We are coming up to chrismtmas and its like a Cola advert but its not “Holidays are coming, Holidays are coming”…Its omicron is coming, omicron is coming and yest its the real thing.

      The amount of data surfacing on fingolimod that has been supported by the manufactureres does not seen great and it may be that the other sphingosine-1-phophates are less of a problem than fingolimod but where is the data and are their any solutions,…the data needs to be deposited in preprint sites as the new COVID wave will be finished before we know anything.

      OK Rant over

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