Twenty-Year Public Health Impact of 7- and 13-Valent Pneumococcal Conjugate Vaccines in US Children

Matt Wasserman; Ruth Chapman; Rotem Lapidot; Kelly Sutton; Desmond Dillon-Murphy; Shreeya Patel; Erica Chilson; Vincenza Snow; Raymond Farkouh; Stephen Pelton

Disclosures

Emerging Infectious Diseases. 2021;27(6):1627-1636. 

In This Article

Abstract and Introduction

Abstract

Pneumococcal conjugate vaccines (PCVs) have been used in the United States since 2000. To assess the cumulative 20-year effect of PCVs on invasive pneumococcal disease (IPD) incidence among children <5 years of age, we analyzed Active Bacterial Core Surveillance data, conducted a literature review, and modeled expected and observed disease. We found that PCVs have averted >282,000 cases of IPD, including ≈16,000 meningitis, ≈172,000 bacteremia, and ≈55,000 bacteremic pneumonia cases. In addition, vaccination has prevented 97 million healthcare visits for otitis media, 438,914–706,345 hospitalizations for pneumonia, and 2,780 total deaths. IPD cases declined 91%, from 15,707 in 1997 to 1,382 in 2019. Average annual visits for otitis media declined 41%, from 78 visits/100 children before PCV introduction to 46 visits/100 children after PCV13 introduction. Annual pneumonia hospitalizations declined 66%–79%, from 110,000–175,000 in 1997 to 37,000 in 2019. These findings confirm the substantial benefits of PCVs for preventing IPD in children.

Introduction

Before 2000, children <2 years of age had the highest incidence of invasive pneumococcal diseases (IPDs) such as bacteremia, meningitis, or other infection of a normally sterile site.[1] Researchers estimated that, in the United States, annual IPD incidence was 165 cases/100,000 children <12 months of age and 203 cases/100,000 children 12–23 months of age.[1] Until the United States began a universal 7-valent pneumococcal conjugate vaccine (PCV7) immunization program for children in 2000, Streptococcus pneumoniae was the leading cause of bacterial meningitis.[1]S. pneumoniae was also the most common bacterial cause of community-acquired pneumonia and otitis media (OM) in young children. Furthermore, in the 1990s, concerns emerged regarding the growing number of pneumococcal isolates with reduced susceptibility to first- and second-line antimicrobial drugs.[1]

PCV7 was the first pneumococcal conjugate vaccine (PCV) approved for use in children <2 years of age in the United States. Pneumococcal polysaccharide vaccines, which preceded PCVs, are not immunogenic in children <2 years of age.[1,2] PCV7 overcame the challenge of poor immunogenicity among infants and young children through conjugation technology; it was introduced into the US infant immunization schedule in 2000, providing direct protection against several serotypes of invasive and noninvasive pneumococcal disease.[3,4] PCV7 protects against the S. pneumoniae serotypes responsible for >80% of IPD cases among children in North America (i.e., serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F).[1,4] In 2010, PCV13, a vaccine providing protection against 6 additional serotypes (i.e., serotypes 1, 3, 5, 6A, 19A, and 7F), was approved in the United States, partially because of increasing incidence of serotypes not covered by PCV7.[1,4]

Clinical trial data suggested that PCV7 would be effective against IPD, OM, and according to a post-hoc analysis, pneumonia.[5] The efficacy of PCV7 (and later PCV13) against all forms of pneumococcal disease was greater than expected, partly because of indirect protection gained through herd immunity.[6–8] The United States was the first country to introduce a PCV program for infants and, during the transition to PCV13, recommended the largest catch-up program for children <5 years of age who had been vaccinated with PCV7.[9] After an initially slow uptake limited by constrained supply, the United States has achieved consistently high (>80%) 3-dose coverage since 2005.[10] It is one of a few countries continuing to use the licensed 4-dose schedule.[10] A 2020 review demonstrated that PCVs were the only vaccines approved by the US Food and Drug Administration that had no postmarketing safety-related label modifications.[11]

We quantified the decrease of IPD incidence associated with 20 years of PCV use in the United States. First, we conducted a literature review to inform a decision analytic model. The model estimated the 20-year cumulative effects associated with the PCV program on cases of IPD, OM, and hospitalizations for pneumonia among children <5 years of age in the United States.

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