Vaccination against pneumococcal pneumonia may not protect patients with rheumatoid arthritis (RA) at risk of infection from pneumonia, according to the results of a clinical trial in Japan. The study also showed that older patients or those with interstitial lung disease are at higher risk of pneumonia.
These findings were published in an article titled “The 23-Valent Pneumococcal Polysaccharide Vaccine In Patients With Rheumatoid Arthritis: A Double-Blinded, Randomized, Placebo-Controlled Trial” in the journal Arthritis Research & Therapy.
RA patients on immunosuppressive treatments are at higher risk of infections, as their immune system is under control of the medication. Pneumonia is one of the main causes of mortality among these patients, and both influenza and pneumococcal infections have been associated with high morbidity in RA patients.
“Recent randomized controlled trials … demonstrated that the 23-valent pneumococcal polysaccharide vaccine (PPSV23) is effective in the prevention of invasive pneumococcal disease among high-risk older populations,” researchers wrote. “However, the vaccine’s protective efficacy against pneumococcal pneumonia in immunosuppressed people, including patients with autoimmune diseases, remains unknown.”
To try to answer this question, the trial (UMIN000009566) enrolled 900 RA patients from different hospitals across Japan who had been previously treated with antirheumatic drugs — TNF inhibitors, Actemra (tocilizumab) and Orencia (abatacept). Patients were then assigned to receive the PPSV23 vaccine (464 patients) or a placebo (436 patients).
Researchers evaluated the incidences of all-cause pneumonia and pneumococcal pneumonia, the most common form of the disease. They also assessed mortality associated with these forms of pneumonia.
Results showed that 17 patients in the vaccine group and 15 patients in the placebo group developed pneumonia, showing that the treatment did not prevent this disease. Also, for RA patients, the overall rate of pneumonia was 21.8 per 1,000 person-years.
Importantly, older age and the presence of interstitial pneumonia were found to be associated with increased risk of pneumonia.
“Our data showed that PPSV23 vaccination was not effective in preventing pneumonia,” researchers wrote. “While PPSV23 vaccination is recommended for adults [age] 65 [and older], our results suggested uncertainty regarding its effectiveness for pneumonia in RA patients at high risk for infections. 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.”