‘Glimpse of hope’ when anti-CD20 drugs limit vaccine antibodies

Reuters - 25/11/2021 - People taking a class of drugs known to limit the antibody response of the mRNA COVID-19 vaccines from Pfizer/BioNTech or Moderna may get some protection from another part of the immune system, according to a small study published in Clinical Infectious Diseases.

The class of anti-CD20 drugs used to treat rheumatoid arthritis, some cancers and other conditions, such as Roche's Rituxan (rituximab), suppress the immune system. But the new findings offer "a glimpse of hope" that these patients may get some protection from the mRNA vaccines after all, the study's leader said.

The researchers studied mRNA vaccine responses in 37 patients taking these drugs for rheumatic diseases or multiple sclerosis, comparing them to 22 individuals with healthy immune systems. Only about 70% of the patients developed antibodies in response to the mRNA vaccines, and their levels were significantly lower than levels in the healthy volunteers.

However, both groups had equal levels of T cells that could recognize and attack the coronavirus.

"Our study suggests that patients on anti-CD20 treatment are able to mount potent T-cell responses to mRNA COVID-19 vaccines," despite impaired antibody responses, the researchers wrote.

The size of the study "does not allow us to draw firm conclusions about protection from severe COVID-19 in these patients," said Dr. Christiane Eberhardt of the University of Geneva in Switzerland. They "should still be vigilant and protect themselves from getting infected."

SOURCE: https://bit.ly/3CUahEe Clinical Infectious Diseases, online November 17, 2021.

By Reuters Staff



Posted on 25 November 20217 December 2021