VIENNA — Pneumococcal vaccination administered 1 month prior to starting methotrexate (MTX) in patients with rheumatoid arthritis (RA) allows a significantly higher immunological response at 1 month and does not affect disease control at 1 year, compared with starting MTX simultaneously with the vaccination, according to data from a randomized trial presented at the annual European Congress of Rheumatology.
“Our patients are more susceptible to infection due to immunosuppressive therapy, and it’s recommended they receive vaccination against pneumococcal infection,” the lead author Jacques Morel, MD, PhD, said in his presentation of results from the VACIMRA study.
Timing the vaccination against pneumococcal disease when initiating MTX in clinical practice has been a point of uncertainty, noted Dr. Morel, a rheumatologist from Centre Hospitalier Universitaire, Montpellier, France.
“How can we deal with this in clinical practice where one recommendation is to vaccine before initiation of methotrexate, but it is also recommended to start methotrexate as soon as the diagnosis of RA is made?” he asked.
Comparing Humoral Response of MTX Started Immediately or 1 Month Post-Vaccination
The prospective, randomized, multicenter trial aimed to compare the rate of humoral immunological response against pneumococcal 13-valent conjugate vaccine (PCV13) in patients with RA who had a Disease Activity Score in 28 joints (DAS28) > 3.2, never taken MTX, and never been vaccinated against pneumococcus. Patients were vaccinated either 1 month before MTX initiation (n = 126) or simultaneously with MTX (n = 123). Oral glucocorticoids were allowed but only at < 10 mg/d. Following PCV13 vaccination, all patients also received the 23-valent pneumococcal polysaccharide vaccine (PPV23) 2 months later.
Concentrations of immunoglobulin (Ig) G antibodies against the 13 serotypes contained within PCV13 were measured using enzyme-linked immunosorbent assay (ELISA) and opsonophagocytic killing assay (OPA) at baseline and during follow-up at 1, 3, 6, and 12 months.
Positive antibody response was defined as a twofold or more increase in the IgG concentration using ELISA. The main outcome was the responder rates at 1 month after PCV13, defined by at least three positive antibody responses out of five of the target PVC13 serotypes (1, 3, 5, 7F, and 19A) using ELISA or OPA. Secondary outcomes included comparisons of the percentage of patients responding to each of the 13 vaccine serotypes at 1 month and after the boost with PPV23 and at 3, 6, and 12 months after vaccination with PCV13. The researchers also measured disease activity, infections, and side effects throughout the study.
Dr. Morel highlighted that all the patients had very early RA of less than 6 months, and that their characteristics at baseline were similar in both groups with 70% women, mean age 55.6 years, RA duration 2 months, 69% positive for anticitrullinated protein antibodies, 21% with erosive disease, and a DAS28 based on C-reactive protein of 4.6.
Response rates in those receiving MTX 1 month after vaccination were significantly higher at 88% with ELISA than those at 75% for immediate vaccination (P < .01) and 96% vs 88% with OPA (P = .02). These responder proportions persisted at the 12-month follow-up measurements, remaining higher in the delayed MTX group for both assays and across the 13 serotypes.
Showing a graph of the antibody responses, Dr. Morel explained that “at 12 months, the curves start to converge, but the difference in antibody titers were still significant for eight of the 13 serotypes.”