Sept. 9 (HealthDay News) -- A recently developed pneumonia vaccine may be more effective in preventing infections in patients with chronic obstructive pulmonary disease (COPD) than the vaccine that is typically used, new research suggests.

Risk of pneumonia can be an ongoing problem for people with COPD, a chronic, progressive disease that causes difficulty breathing and chest tightness. The U.S. Centers for Disease Control and Prevention recommends that all adults with COPD be vaccinated against pneumonia with a vaccine referred to as PPSV23 (23-valent pneumococcal polysaccharide vaccination).

But the effectiveness of the vaccine in people with COPD hasn't been sufficiently proven, according to the study that will appear in the Sept. 15 issue of the American Journal of Respiratory and Critical Care Medicine.

"Reasonable effectiveness for this vaccine has been demonstrated in cohort studies in adults with lung disease," said study author Dr. Mark Dransfield of the University of Alabama at Birmingham, in a news release from the American Thoracic Society. "[However,] debate remains about its immunogenicity and effectiveness in COPD."

In the current study, researchers inoculated 120 adults with moderate to severe COPD with either PPSV23 or a newer vaccine, PCV7.

Several indicators showed the PCV7 vaccine produced a heightened immune response as compared to the older vaccine.

The blood of patients who had received PCV7 vaccine was also more effective at killing pneumonia-causing bacteria in six of seven serotypes, or groups of microorganisms, one month after vaccination, the researchers found.

"We have shown that PCV7 induces a superior immune response to PPSV23 in COPD at one month post-vaccination," Dransfield stated in the news release.

However, older age and prior vaccination with PPSV23 blunted the efficacy of the PCV7 vaccine, the researchers noted, and further study is needed.

SOURCE: American Thoracic Society, news release, Sept. 8, 2009