A third dose of an mRNA COVID-19 vaccine was safe and associated with modestly increased levels of antibodies in patients with reduced protective humoral immunity before reimmunization.
A third dose of one of either the Pfiizer of Moderna COVID-19 vaccines was safe and associated with modestly increased levels of antibodies against the disese, according to a new study.1
Around 80% of all MS patients treated with anti-CD20 therapy or fingolimod (Novartis’s Gilenyea) have weak humoral immune responses after two doses of messenger RNA (mRNA) COVID-19 vaccines, wrote Marton Konig, M.D., Ph.D., an Oslo University Hospital neurologist, in a short report about their results in the Jan. 24, 2022, issue of JAMA Neurology.
Konig and colleagues enrolled patients from three university hospitals starting March 2021. After two doses of mRNA vaccines, the patients were offered a third dose of the either the Pfizer or Moderna COVID-19 vaccines
Antibodies to the SARS-CoV-2 virus that causes COVID-19 were measured in all patients 3 to 12 weeks after full vaccination and three to 5 weeks after revaccination.
Konig and team found that a third dose of the mRNA COVID-19 vaccines was safe and associated with modestly increased levels of antibodies in patients with reduced protective humoral immunity before reimmunization.
A higher proportion of patients who were treated with anti-CD20 therapy experienced a strong antibody response than patients treated with fingolimod. Twenty-five of the 101 patients treated with anti-CD20 therapy had antibody levels that were high enough to protect against the SARS-CoV-2 virus compared with just two of the 29 patients treated with fingolimod.
The anti-CD20 drugs include Rituxan (rituximab) and Ocrevus (ocrelizumab).
“A 25% increase in the number of patients who experienced seroconversion after revaccination and who were treated with anti-CD20 therapy may be of clinical relevance, as these patients have an approximately three-fold risk of developing serious COVID-19,” Konig wrote.
The results suggest that revaccination of these patients should be considered, Konig added.