Kiyoski Migita, from the Japanese Hospital Organization and Department of Rheumatology at Fukushima Medical University, and colleagues conducted a double-blinded, randomized, placebo-controlled trial across rheumatology departments in Japanese National Hospital Organization hospitals. The study included 900 RA patients who had been treated with biological or immunosuppressive agents.

The study participants were randomly assigned to receive PPSV23 (n=464) or placebo (n=436). The researchers examined incidences of all-cause pneumonia and pneumococcal pneumonia as the primary end point and death from pneumococcal pneumonia, all-cause pneumonia, or other causes as the secondary end point.The researchers found that 17 of the patients (3.7%) who received the vaccine and 15 of the patients (3.4%) in the placebo group developed pneumonia. The overall rate of pneumonia was 21.8 per 1,000 person-years among patients with RA. In addition, the presence of interstitial pneumonia (hazard ratio, 3.601) was associated with an increased risk of pneumonia among RA patients.

The investigators note that the patient population in the current study had a high risk of infection, and the results may not be applicable to other RA populations.

“While PPSV23 vaccination is recommended for adults ≥65 years of age, our results suggested uncertainty regarding its effectiveness for pneumonia in RA patients at high risk for infections,” the study authors wrote. “Clinicians should keep in mind the patient’s age and the presence of interstitial pneumonia because such patients are at an increased risk of developing pneumonia.”