A vaccine against pneumococcal pneumonia does not prevent rheumatoid arthritis patients from contracting the disease, according to the results of a large clinical trial.
Although the analysis included 900 patients, researchers caution that more studies are needed to better understand the impact of vaccination on pneumonia in rheumatoid arthritis.
The study, “The 23-valent pneumococcal polysaccharide vaccine in patients with rheumatoid arthritis: a double-blinded, randomized, placebo-controlled trial,” appeared in the journal Arthritis Research & Therapy.
Treating rheumatoid arthritis with immunosuppressant drugs or newer disease-modifying treatments puts patients at increased risk of developing serious infections. Pneumonia is one of the major causes of death among arthritis patients. Research shows that the most common cause of community-acquired pneumonia is the Streptococcus pneumonia bacteria.
Pneumovax, which effectively wards off pneumonia in older people at risk, also offers protection against several different bacterial strains. To test if this protection extends to patients with rheumatoid arthritis, researchers at the Fukushima Medical University and colleagues at the Japanese National Hospital Organization (NHO) designed a clinical trial.
The trial, (UMIN000009566), registered at UMIN, the Japanese University hospital Medical Information Network , recruited 900 patients across clinics in Japan who were randomized to receive vaccination or placebo in a double-blind manner.
Patients were divided into several risk groups. These consisted of people with rheumatoid lung disease, those treated with biological drugs, those receiving immunosuppressants, patients getting more than 5 mg per day corticosteroids, and finally, patients classified as Steinbrocker stage 3 or 4 (the highest disability levels in rheumatoid arthritis).
Results showed that during the one-year follow-up period, 17 (or 3.7 percent) of the 464 vaccinated patients came down with pneumonia. Similarly, 15 (or 3.4 percent) of the 436 patients who had received placebo contracted the disease — meaning there was no difference in pneumonia rates between the two study groups.
Analyses could confirm the cause of pneumonia in only 12 of the 32 patients who fell ill. Of those, two cases of pneumococcal pneumonia were seen in the vaccinated group and one in the placebo group.
The time until patients developed pneumonia did also not differ between the groups, as pneumonia-free survival calculations were similar. The various risk factors had no effect on one’s risk of getting pneumonia. But the researchers found that older patients and those with interstitial pneumonia were more likely to fall ill.
Japanese authorities suspended the study in November 2014, ruling that everyone age 65 or older should receive the vaccination tested in the trial. Those receiving placebo who were older than 65 were then unblinded and given an active vaccination, and the researchers cautioned that, for this reason, the study’s results may be skewed.
Nonetheless, the team concluded that PPSV23 vaccination [Pneumovax] was not effective in preventing pneumonia.
“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 researchers reported. “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.”