RA Drug Reduces Seasonal Flu Vaccine Effectiveness
Posted Jan 07 2010 6:00am
People with Rheumatoid Arthritis (RA) have depressed immune systems and are therefore encouraged to get the annual flu vaccination. However, a recent study has found that RA patients who have taken rituximab may not get the same protection against the seasonal flu.
Rituximab depletes B cells, which are responsible for producing antibodies against infections.
Dutch researchers conducted a study of 72 people from the 2007-2008 flu season. Twenty-three were RA patients who were treated with rituximab, 20 were RA patients who were treated with methotrexate, and 29 were healthy controls. In addition, the rituximab group was subdivided into those who received rituximab six to ten months prior to the flu vaccination, and those who received the vaccine four to eight weeks after treatment with rituximab.
Eleven of the patients received rituximab four to eight weeks before vaccination (early group), and twelve had received it six to ten months before vaccination (late group).
Sander van Assen, MD, of University Medical Center Groningen, and colleagues found that patients that received rituximab four to eight weeks prior to the vaccination did not develop antibodies against the seasonal flu strains targeted by the vaccine.
Those who received rituximab six to ten months prior to the vaccination showed lower levels of antibodies than the controls, but higher than the early group.
The researchers also found that there was no significant difference in the level of antibodies for those on methotrexate compared to the controls.
In the study report, published in the January issue of Arthritis & Rheumatism, the researchers recommended giving the seasonal flu vaccine well before treatment with rituximab.