Study shows how MS patients treated with Rituximab react to COVID-19 vaccination

MS patients treated with Rituximab have better responses to the COVID-19 vaccine if they have higher B cell counts. This is the finding of a study from Uppsala University published in the journal JAMA Network Open. In patients with B cell counts of 40/µL (microlitres) or more, 9 of 10 patients developed protective levels of antibodies, while significantly fewer with lower counts had similar responses. In Sweden, Rituximab is the most common medicine for multiple sclerosis (MS), but it is also used for many other diseases. The medicine is given as a drip, normally once or twice a year, and has a documented good effect on slowing the progression of MS. The treatment knocks out the body's B cells, which are an important part of our immune system though they also contribute to the MS disease process. As a result, the treatment increases the risk of patients suffering from serious infections, such as COVID-19. Having low levels of B cells also makes it more difficult for the body to form protective antibodies against viruses and bacteria, which is the primary purpose of vaccinations. In this case, this concerns the S protein in the SARS-CoV-19 virus.