In a guest post on “The MS Blog,” Dr Oliver Findling summarised a recent study on which he was the principal investigator: Humoral Immune Response after the Third SARS-CoV-2 mRNA Vaccination in CD20 Depleted People with Multiple Sclerosis. People with multiple sclerosis (pwMS) can face great risk during the COVID-19 pandemic, as CD20 depletion is a risk factor for unfavourable outcomes of COVID-19. Additionally, depleted B cell levels can mean limited IgG response to mRNA based COVID-19 vaccines. As such, Findling’s group investigated seroconversion after the third mRNA COVID-19 vaccine in B cell depleted pwMS with limited or no IgG response after the first and second vaccines. The study participants—16 pwMS treated with ocrelizumab or rituximab—received a third dose of either the Moderna or Pfizer-BioNTech mRNA vaccine. Only one of 16 patients had a clinically relevant IgG titre after the third vaccination. Additionally, at the time of the third vaccination, only the seroconverted patient had measurable B cell counts. The authors concluded that the development of immune response from mRNA-based COVID-19 vaccines remains rare, even after three doses of the vaccine.

References

1. Achtnichts L et al. Vaccines. 2021;9:1470