Conjugate pneumonia vaccines cost-effective for adults, model finds

Vaccinating adults with the 13-valent pneumococcal conjugate vaccine (PCV13) may be more cost-effective than vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPSV23), a new study found.

The findings were based on a Markov model of hypothetical cohorts of U.S. 50-year-olds, using current data (from the Centers for Disease Control and Prevention, the National Hospital Discharge Survey and the National Health Interview Survey, among other sources) and expert estimates. Researchers calculated the number of pneumococcal disease cases that would be prevented by various vaccination strategies and calculated the resulting gains in quality-adjusted life-years (QALYs). The results were published in the Feb. 22/29 Journal of the American Medical Association.

If PCV13 were simply substituted for PPSV23 in current recommendations (vaccination at age 65 or younger if comorbidities are present), the cost per QALY would be $28,900 with PCV13 compared to $34,000 with PPSV23. If vaccination recommendations were increased to routine vaccination at age 50 and 60, PCV13 would cost $45,100 per QALY, the researchers calculated. They found overall that PCV13 vaccination compared favorably with PPSV23 and thus concluded that a change in vaccine recommendations might lead to a cost-effective reduction in pneumococcal disease burden.

However, the study was limited by the lack of data about the vaccines' effects, the authors noted. For example, if PCV13 were found to have low effectiveness against nonbacteremic pneumococcal pneumonia (NPP), it would not compare as well against PPSV23. Or, if recent recommendations to vaccinate children with PCV13 create a large amount of herd protection for adults, that would affect the value of vaccinating adults with PCV13. The researchers expressed optimism than current trials will provide more data on these questions.

However, an accompanying editorial noted that the difficulty of accurately diagnosing NPP makes a clear answer to that question unlikely. Policymakers will have to decide on a vaccination strategy without definitive data, the editorialist said, adding that analyses such as this one may provide a reasonable framework for the decision. Whatever is decided, ongoing advances in vaccines appear likely to reduce the burden of pneumococcal infections, he concluded.