Pneumococcal Vaccination Strategies. An Update and Perspective

Abstract

Streptococcus pneumoniae is an important global pathogen that causes a wide range of clinical disease in children and adults. Pneumococcal pneumonia is by far the common presentation of noninvasive and invasive pneumococcal disease and affects the young, the elderly, and the immunocompromised disproportionately. Patients with chronic pulmonary diseases are also at higher risk for pneumococcal infections. Substantial progress over the century has been made in the understanding of pneumococcal immunobiology and the prevention of invasive pneumococcal disease through vaccination. Currently, two pneumococcal vaccines are available for individuals at risk of pneumococcal disease: the 23-valent pneumococcal polysaccharide vaccine (PPV23) and the 13-valent pneumococcal protein-conjugate vaccine (PCV13). The goal of pneumococcal vaccination is to stimulate effective antipneumococcal antibody and mucosal immunity response and immunological memory. Vaccination of infants and young children with pneumococcal conjugate vaccine has led to significant decrease in nasal carriage rates and pneumococcal disease in all age groups. Recent pneumococcal vaccine indication and schedule recommendations on the basis of age and risk factors are outlined in this Focused Review. As new pneumococcal vaccine recommendations are being followed, continued efforts are needed to address the vaccine efficacy in the waning immunity of the ever-aging population, the implementation of vaccines using two different vaccines under very specific schedules and their real world clinical and cost effectiveness, and the development of next generation pneumococcal vaccines.

Keywords: PCV-13 vaccine; Streptococcus pneumoniae; pneumococcal vaccines; pneumonia.

Figure 1.

(A) Pneumococcus bacteria and virulence factors including capsular polysaccharide. (B) Immune response to polysaccharide and protein-polysaccharide conjugate vaccines. MHC = major histocompatibility complex; TCR = T cell receptor. Adapted by permission from Reference .

Figure 2.

Pneumococcal serotypes in vaccines.

Figure 3.

Advisory Committee on Immunization Practices recommendations for pediatric pneumococcal vaccination. *See Table 2 for relevant high-risk comorbidities and immunocompromised conditions. ^†Functional or anatomic asplenia and immunocompromised conditions. Adapted from CDC guidelines for appropriate overlap schedules for individuals who received partial series of PCV7 and/or PPSV23 (70).

Figure 4.

Advisory Committee on Immunization Practices recommendations for adult pneumococcal vaccination: vaccine-naive individuals. *Includes patients with functional/anatomic asplenia, immunocompromising conditions, cerebrospinal fluid (CSF) leak, or cochlear implants (see Table 2). ^†Includes patients with normal immunity but certain comorbid conditions.

Figure 5.

Advisory Committee on Immunization Practices recommendations for adult pneumococcal vaccination: individuals with prior PPSV23 vaccination. *Includes patients with functional/anatomic asplenia, immunocompromising conditions, cerebrospinal fluid (CSF) leak, or cochlear implants (see Table 2).