Immunisation against pneumococcus has been shown to reduce pneumonia in rheumatoid arthritis (RA). There is concern that methotrexate may reduce its efficacy. There are very few objective data on the effect of methotrexate on the efficacy of pneumococcal vaccination with pneumovax, and no objective evidence on whether revaccination is necessary in RA patients on methotrexate.
The authors collected information from 180 RA patients on methotrexate relating to their vaccination status and assayed their pneumococcal antibody levels. Data on pulmonary infection were retrieved in the same patients over the preceding decade.
Full data were available for 152 patients, of whom 28 had never been vaccinated against pneumococcus. Median levels were significantly higher in those who had been vaccinated. Unvaccinated patients and those taking oral prednisone were more likely to have had pneumonia in the previous 10 years. The RR for developing pneumonia among non-vaccinated patients was 9.7 (p=0.005) and among steroid-treated patients was 6.5 (p=0.001), after adjusting for age, gender, disease duration and comorbidity. No significant correlation was found between pneumococcal antibody levels and time since vaccination.
This study suggests that a single administration of pneumovax early in RA offers up to 10 years protection against the development of pneumococcal pneumonia in RA patients on methotrexate.