In a specially-called teleconference meeting, the ACIP issued recommendations for the use of 13-valent pneumococcal conjugate vaccine (PCV13), as well as pneumococcal polysaccharide vaccine (PPSV23) in adults aged 65 years and older. Although PCV13 had been licensed by the FDA for use in adults 50 years and older in late December 2011, the ACIP decided to defer making a recommendation pending the results of two studies: 1) the indirect impact in the adult population of the routine use of PCV13 in children, and 2) the results of a clinical trial evaluating the effectiveness of PCV13 in preventing community-acquired pneumonia in adults, which was ongoing in the Netherlands (the CAPITA trial).
Surveillance of invasive pneumococcal disease (defined by the isolation of pneumococci from a normally sterile site such as the bloodstream or cerebrospinal fluid) is conducted by the CDC-sponsored Emerging Infections Program in collaboration with select state health departments and academic centers. The results from this comprehensive population-based system now clearly indicate that the universal use of PCV13 in children has the salubrious indirect effect of also reducing invasive disease in adults that is caused by the pneumococcal serotypes included in the vaccine. This indirect protective effect is similar to that seen after the introduction of PCV7. It results from the vaccine’s prevention of nasopharyngeal pneumococcal carriage which, in turn, interrupts the transmission of pneumococci from young children to adults.
On its face, this result could have provided a reason to question the need to immunize the adults themselves. However, the indirect effect was becoming evident only gradually. A substantial burden of potentially vaccine-preventable disease in adults remained. Among adults aged 65 and older, it was estimated that 2,600 cases of invasive pneumococcal disease still occurred in 2013 due to serotypes in PCV13.
Beyond that, some 50,000 cases of community-acquired pneumonia caused by PCV13 serotypes also occurred that year. Thus, a substantial potentially-preventable disease burden remained. It was in this context that results of the CAPITA trial played a decisive role in the deliberations.
CAPITA demonstrated that vaccination of adults aged 65 and older resulted in a 75% reduction of vaccine-type invasive disease. as well as a 45% reduction in non-bacteremic community-acquired pneumonia. These were noteworthy benefits. Add to that a reasonable cost-benefit analysis and the ACIP was persuaded to recommend this clinical and public health benefit for older adults, hoping that the upcoming fall-winter influenza immunization season would be accompanied by a concurrent surge in pneumococcal vaccination.
The recommendation adds PCV13 to the already existing PPSV23 recommendations; both vaccines are to be used. The immune response seems to be improved when PCV13 is given first. Thus, those who attain age 65 and who have not received pneumococcal vaccine previously should be given PCV13 followed by PPSV23 6 to 12 months later. Patients 65 years old or older who previously have received PPSV23 should be given PCV13 if an interval of at least 1 year has elapsed. That’s a bit complex and we must recognize that the promulgation of a recommendation is but the first step in an elaborate implementation process. Here are a few challenges:
- Getting the word out to all our primary care colleagues so they can integrate PCV13 into their routines and, hopefully, keep the two different pneumococcal vaccines distinct;
- Improving state vaccine registries so that they can accept records of adult immunizations. All too often adults are clueless about their vaccination histories. The new dual pneumococcal vaccine recommendations make this an imperative;
- Augmenting Medicare coverage to include two doses of pneumococcal vaccine. At present, Medicare covers only one dose. CMS has a process to change its policies, but it is lengthy. The agency has been encouraged to expedite this in the interest of public health. In the meantime, we can get many new 65 year-olds started on their pneumococcal vaccine series.
William Schaffner, MD
Infectious Disease News Editorial Board member
Disclosures: Schaffner reports no relevant financial disclosures.