Effect of Pneumococcal Conjugate Vaccines on Viral Respiratory Infections: A Systematic Literature Review

Pneumococcal conjugate vaccines (PCV) have been licensed for the prevention of pneumococcal disease and were effective in reducing their incidence. Emerging evidence reported that PCVs might also reduce viral respiratory tract infections (RTI) by affecting pneumococcal-viral interaction. Our member, P95 and Pfizer performed a systematic literature review to summarize the evidence on the effects of PCVs against virus-related RTI in children and adults. Based on 16 eligible studies, results indicate that PCVs were associated with protection against some viral RTI, with the strongest evidence in children and in particular for influenza. For adults, limited evidence was generally consistent with pediatric data.

ABSTRACT

Background

In addition to preventing pneumococcal disease, emerging evidence indicates that pneumococcal conjugate vaccines (PCVs) might indirectly reduce viral respiratory tract infections (RTIs) by affecting pneumococcal-viral interactions.

Methods

We performed a systematic review of interventional and observational studies published during 2000–2022 on vaccine efficacy/adjusted effectiveness (VE) and overall effect of PCV7, PCV9, PCV10, or PCV13 against viral RTIs.

Results

Sixteen of 1671 records identified were included. Thirteen publications described effects of PCVs against viral RTIs in children. VE against influenza ranged between 41% and 86% (n = 4), except for the 2010–2011 influenza season. In a randomized controlled trial, PCV9 displayed efficacy against any viral RTI, human seasonal coronavirus, parainfluenza, and human metapneumovirus. Data in adults were limited (n = 3). PCV13 VE was 4%–25% against viral lower RTI, 32%–35% against coronavirus disease 2019 outcomes, 24%–51% against human seasonal coronavirus, and 13%–36% against influenza A lower RTI, with some 95% confidence intervals spanning zero. No protection was found against adenovirus or rhinovirus in children or adults.

Conclusions

PCVs were associated with protection against some viral RTI, with the strongest evidence for influenza in children. Limited evidence for adults was generally consistent with pediatric data. Restricting public health evaluations to confirmed pneumococcal outcomes may underestimate the full impact of PCVs.

To review the complete results of the research, please follow the link to The Journal of Infectious Diseases: https://academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiae125/7625230?login=false