H1N1 Vaccine Safe in RA Patients on Treatment

Alice Goodman

June 1, 2011 — The H1N1 vaccine is safe in patients with rheumatoid arthritis (RA) on active antirheumatic therapy, regardless of age, level of disease activity, and medications they were taking, according to a study presented here at the European League Against Rheumatism (EULAR) Congress 2011.

However, RA patients had a 20% to 30% lower response rate than control subjects, suggesting that some RA patients will require a different protocol when a new vaccine is introduced.

"The lower response rate in RA patients shows that we cannot be at ease with new vaccines [in RA patients on active treatment]. Even though RA patients do as well as healthy people with seasonal flu and pneumococcal vaccines, we cannot extrapolate that the immune response will be the same with a new vaccine for another pandemic. . . . We need to monitor response rates to see if protection is adequate. If not, new protocols and perhaps higher doses might be necessary," stated senior author of this study, Ieda Laurindo, MD, from the University of Sao Paulo, Brazil.

The hospital-based study compared 340 RA patients receiving active therapy and 234 healthy control subjects; all participants received H1N1 vaccination. After immunization, the seroprotection rate was 60.1% in the RA group and 82.9% in the control group (P < .001). Seroconversion rates were 53.4% and 76.9%, respectively (P < .001).

Vaccination did not affect disease activity in RA patients, according to the disease activity score in 28 joints (DAS28). Only 9 patients (2.6%) had worsening RA symptoms. Methotrexate therapy was associated with a lower response rate, but this is difficult to say with certainty, she said, because all patients were receiving combination therapy. Treatment with classic disease-modifying antirheumatic drugs (DMARDs) or anti-tumor necrosis factor (TNF) agents had no influence on response.

Vaccination was well tolerated in both groups. More adverse events were reported in the RA group than in the control group (42.0% vs 30.8%). There were no serious adverse events; the RA group had more systemic reactions, and the control group had more local reactions.

"The major take-away message from this study is that we have to vaccinate our RA patients to protect them against pandemics. Many patients are not being vaccinated, and the majority of RA patients are older and vulnerable," Dr. Laurindo said.

"An important question in RA is whether vaccination can induce disease activity. This study and other studies say 'no'. The next question is whether the vaccine is effective in RA. These data suggest that at least 20% of patients [receiving active therapy] have less response. Important questions to explore are whether we should increase the dose of a new vaccine, and how to identify the 20% to 30% of patients with suboptimal response," said Maxime Dougados, MD, who moderated a formal press conference at EULAR. Dr. Dougados is professor of rheumatology at René Descartes University in Paris, France.

Dr. Laurindo has disclosed no relevant financial relationships. Dr. Dougados reports many relationships with industry, but none related to this study of vaccines.

European League Against Rheumatism (EULAR) Congress 2011: Abstract OP0147. Presented May 26, 2011.