Jan. 11 (HealthDay News) -- New research offers a caution to rheumatoid arthritis patients who take the drug rituximab (Rituxan): The flu vaccine is safe, but it's ineffective during the first six months following treatment with Rituxan.
The researchers also found that previous flu vaccination does help provide some protection against the flu, and the vaccine won't make the arthritis symptoms worse.
The study findings are published in the January issue of Arthritis & Rheumatism.
Rheumatoid arthritis, which is caused when the immune system attacks the body, affects about 4.6 million people around the world. Doctors recommend that these patients get vaccinated against influenza each year -- including the H1N1 swine flu this year -- because they have weakened immune systems.
The new study, by Dr. Sander van Assen and colleagues at the University Medical Center Groningen in the Netherlands, included rheumatoid arthritis patients who took rituximab or methotrexate, as well as a group of healthy people.
Those who took rituximab took longer to develop immunity to flu after being vaccinated, the researchers found.
"Individuals who have compromised immune systems, such as with rheumatoid arthritis, are at risk for complications from contracting the flu virus," van Assen said in a news release from the American College of Rheumatology. "We recommend yearly influenza vaccination for all rheumatoid arthritis patients and pre-emptive vaccination for flu should be considered by those patients who start rituximab treatment."
SOURCE: American College of Rheumatology, news release, Jan. 6, 2010