Effectiveness of the 23-Valent Pneumococcal Polysaccharide Vaccine (PPV23) against Pneumococcal Disease in the Elderly: Systematic Review and Meta-Analysis

Abstract

BackgroundRoutine vaccination of elderly people against pneumococcal diseases is recommended in many countries. National guidelines differ, recommending either the 23-valent polysaccharide vaccine (PPV23), the 13-valent conjugate vaccine (PCV13) or both. Considering the ongoing debate on the effectiveness of PPV23, we performed a systematic literature review and meta-analysis of the vaccine efficacy/effectiveness (VE) of PPV23 against invasive pneumococcal disease (IPD) and pneumococcal pneumonia in adults aged ≥60 years living in industrialized countries.MethodsWe searched for pertinent clinical trials and observational studies in databases MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. We assessed the risk of bias of individual studies using the Cochrane Risk of Bias tool for randomized controlled trials and the Newcastle-Ottawa Scale for observational studies. We rated the overall quality of the evidence by GRADE criteria. We performed meta-analyses of studies grouped by outcome and study design using random-effects models. We applied a sensitivity analysis excluding studies with high risk of bias.ResultsWe identified 17 eligible studies. Pooled VE against IPD (by any serotype) was 73% (95%CI: 10–92%) in four clinical trials, 45% (95%CI: 15–65%) in three cohort studies, and 59% (95%CI: 35–74%) in three case-control studies. After excluding studies with high risk of bias, pooled VE against pneumococcal pneumonia (by any serotype) was 64% (95%CI: 35–80%) in two clinical trials and 48% (95%CI: 25–63%) in two cohort studies. Higher VE estimates in trials (follow-up ~2.5 years) than in observational studies (follow-up ~5 years) may indicate waning protection. Unlike previous meta-analyses, we excluded two trials with high risk of bias regarding the outcome pneumococcal pneumonia, because diagnosis was based on serologic methods with insufficient specificity.ConclusionsOur meta-analysis revealed significant VE of PPV23 against both IPD and pneumococcal pneumonia by any serotype in the elderly, comparable to the efficacy of PCV13 against vaccine-serotype disease in a recent clinical trial in elderly people. Due to its broader serotype coverage and the decrease of PCV13 serotypes among adults resulting from routine infant immunization with PCV13, PPV23 continues to play an important role for protecting adults against IPD and pneumococcal pneumonia.

State-of-the-art in the pneumococcal field: Proceedings of the 11th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD-11)

“…The dominant presentation of pneumococcal CAP is nonbacteraemic/non-invasive disease while invasive infections involving normally sterile sites occur in a quarter of cases [20]. Vaccines which contain purified capsular polysaccharides (PPVs) are effective against invasive disease in adults but their efficacy against non-invasive pneumonia remains controversial [21,22]. It is also unclear how PPV protection against disease and carriage wanes over time in adults [22].…”

“…Vaccines which contain purified capsular polysaccharides (PPVs) are effective against invasive disease in adults but their efficacy against non-invasive pneumonia remains controversial [21,22]. It is also unclear how PPV protection against disease and carriage wanes over time in adults [22]. At ISPPD-11, there was a focus on protection of adults and innovations for timely diagnosis of CAP.…”

Immunogenicity Prediction by VaxiJen: A Ten Year Overview

“…Currently, two vaccines for prevention from pneumonia caused by S. pneumoniae are licensed for adults: 23-vallent polysaccharide vaccine (PPV23) and 13-valent conjugate vaccine (PCV13) [22]. Both vaccines contain capsular polysaccharides eliciting weak immunogenicity in children, and are unable to induce effective immune memory [2].…”

A pharmacy resident‐driven pneumococcal vaccination protocol increases vaccination rates in hospitalized patients over 65 years

“…The annual rate of IPD is 15 cases/100 000 and 6 cases/100 000 due to serotypes that are included in the PPSV23 and PCV13 vaccines, respectively . In patients age 60 years and older, PPSV23 was estimated to have 64% efficacy against pneumococcal pneumonia and 73% efficacy against IPD . Similarly, the use of PCV13 in patients age 65 years and older with no previous pneumococcal vaccination (PCV13 or PPSV23) demonstrated 45% efficacy against noninvasive vaccine‐type community‐acquired pneumonia and 75% efficacy against vaccine‐type IPD …”