A study published in Biomedicines revealed that myelofibrosis people following 2 doses of mRNA SARS-CoV-2 vaccine, develop a humoral response with slower kinetics in comparison with healthy people. Furthermore, a decreased antibody inhibition binding activity was noted, particularly with ruxolitinib therapy.

The study investigators prospectively profiled the spike-specific antibody response and the effect of ruxolitinib therapy in myelofibrosis patients at seven and thirty days following the administration of 2nd dose of the mRNA vaccine. The study recruited 42 people with myelofibrosis, vaccinated with mRNA SARS-CoV-2 vaccine, and 40 healthy, vaccinated volunteers as the control group.

Participants having myelofibrosis were treated (16/42) or not (26/42) with ruxolitinib therapy. Collection of plasma samples was done at baseline (prior to vaccination), seven and thirty days from the 2nd dose of mRNA SARS-CoV-2 vaccine received three-four weeks following the 1st dose. Overall, 76% of myelofibrosis people developed spike-specific IgG following the 2nd dose of the mRNA SARS-CoV-2 vaccine.

However, the antibody response dynamic exhibited slower kinetics in comparison with the healthy subjects, indicating a decreased capability of their immune system to quickly react to vaccination. A decreased angiotensin-converting enzyme 2/receptor binding domain (ACE2/RBD) binding suppression activity of spike-specific antibodies was also noted, particularly in people administered ruxolitinib.

This knowledge is of vital importance for assessing the requirement for repeated booster doses of mRNA coronavirus vaccines and guide vaccination policies tailored for myelofibrosis people, concluded the study authors.