21. Systematic Review and Meta-Analysis of Pneumococcal Vaccine Effectiveness against Invasive Pneumococcal Disease among Adults

Abstract

Abstract Background Two new pneumococcal conjugate vaccines (PCVs), PCV15 and PCV20, are anticipated to be licensed for use in U.S. adults in 2021. To help inform the U.S. Advisory Committee on Immunization Practices’ discussions on pneumococcal vaccine use among adults, we conducted a systematic review and meta-analysis. We specifically looked at efficacy or effectiveness of PCV13 and pneumococcal polysaccharide vaccine (PPSV23) against invasive pneumococcal disease (IPD) in adults. Methods We conducted a search of English literature published from 1998 – February 2021 on PCV13 and PPSV23 efficacy or effectiveness studies using eight major databases. Studies targeting adults with immunocompromising conditions were excluded. Title and abstract screening of identified studies and data abstraction were performed by two reviewers. Results were stratified by vaccine product, outcome evaluated (vaccine type (VT) or all IPD), study design, and effect measure. Random effects models were used to pool estimates by stratum. Results Of 3,422 citations reviewed, we identified 26 IPD studies; 4 on PCV13, 22 on PPSV23, 18 with all IPD, and 17 with VT-IPD (Table) as an outcome. Only one randomized-controlled trial (RCT) was identified for PCV13 with an efficacy of 52% (95% CI: 22%, 77%) against all IPD and 75% (95% CI: 41%, 91%) against VT-IPD. A pooled vaccine effectiveness (VE) estimate from three observational studies evaluating PCV13 was 56% (95% CI: 32%, 71%; I2 =12.8) against VT-IPD. Two RCTs evaluating PPSV23 reported efficacies against all IPD ranging between 79-86%; an additional RCT reported no IPD cases during RCT. Vaccine effectiveness estimates from 14 observational studies evaluating PPSV23 ranged between 29-76% against all IPD. Pooled VE estimates from 12 observational studies showed PPSV23 effectiveness against VT-IPD was 38% (95% CI: 28% to 46%; I2 =40.8). Table. Efficacy and effectiveness studies against vaccine-type invasive pneumococcal disease Conclusion Evidence suggests both pneumococcal vaccines are effective against VT-IPD in adults. Given that PCV15 and PCV20 are expected to be licensed based on immunogenicity data and no clinical efficacy data are available for these new vaccines, the findings from this review will help inform policy discussions on use of the new PCVs among adults. Disclosures All Authors: No reported disclosures