The 13-valent pneumococcal vaccine had an unadjusted vaccine effectiveness of around 73% against vaccine-type community-acquired pneumonia in the first real-world test of the vaccine among seniors in the United States, researchers reported in Clinical Infectious Diseases.
In 2014, the CDC’s Advisory Committee on Immunization Practices (ACIP) recommended that unvaccinated U.S. adults aged 65 years and older receive PCV13, followed by a dose of the 23-valent pneumococcal vaccine, and a recent study supported its ongoing use this population.
The ACIP recommendation followed results from a double-blind, placebo-controlled randomized clinical trial in the Netherlands that showed the vaccine was effective. But according to the authors of the new study, there were questions about whether that efficacy “would be reflective of the real-life experience of an adult population as clinically and demographically diverse as the United States,” where more than 30% of seniors have received PCV13 since the ACIP vote.
They used a test-negative design to evaluate the real-world effectiveness of the vaccine on 2,034 hospitalized patients in Louisville, Kentucky, from April 2015 through April 2016. They enrolled patients with confirmed CAP caused by a serotype covered by the vaccine. The remaining CAP patients served as test-negative controls.
Overall, 68 patients had infections caused by PCV13 serotypes (cases) and 1,966 did not (control). According to the researchers, cases were less likely to have received PCV13 than controls — 4.4% vs. 14.5%, with an unadjusted vaccine effectiveness of 72.8% (95% CI, 12.8%-91.5%).
“To date, PCV13 uptake in older U.S. adults has been modest,” the researchers concluded. “Given the effectiveness of PCV13 and the remaining [vaccine-type CAP] disease burden in adults aged 65 years and older observed in our study, the potential public health benefit of continued PCV13 vaccination in this U.S. population, and in other adult populations globally, remains substantial.” – by Gerard Gallagher
Disclosures: Please see the study for all authors’ relevant financial disclosures.