What is the efficacy of the Pneumococcal (Streptococcus pneumoniae) vaccine?

From the Guidelines

Pneumococcal vaccines are highly effective at preventing serious pneumococcal infections, with efficacy rates ranging from 40-75% against invasive pneumococcal disease in adults, including the elderly, as demonstrated by recent meta-analyses and systematic reviews 1.

Key Points

• The 23-valent polysaccharide pneumococcal vaccine (PPV) is recommended for all adult persons at risk of pneumococcal disease, including those older than 65 years, and individuals with certain medical conditions such as chronic obstructive pulmonary disease, diabetes mellitus, and functional or anatomical asplenia 1.
• Revaccination with PPV is recommended once, and not earlier than 5 years after primary vaccination, in asplenic patients and can be considered in the elderly and other high-risk groups 1.
• While there is limited evidence on the use of conjugate pneumococcal vaccines in adults, recent studies suggest that they may provide a superior immune response in elderly patients or high-risk adults compared to PPV 1.

Efficacy and Effectiveness

• The efficacy of PPV in preventing invasive pneumococcal disease (IPD) has been consistently demonstrated in meta-analyses and systematic reviews, with protective efficacy ranging from 40-75% in healthy adults, including the elderly 1.
• The vaccine has also been shown to be effective in preventing all-cause pneumonia and pneumococcal pneumonia in certain populations, such as nursing home residents, with a recent study demonstrating a 45% reduction in all-cause pneumonia and a 64% reduction in pneumococcal pneumonia 1.

Recommendations

• The CDC recommends pneumococcal vaccination for all adults 65 years and older, as well as for adults 19-64 years with certain medical conditions, such as chronic lung disease, heart disease, and diabetes mellitus 1.
• Vaccination with PPV has been shown to be cost-effective in preventing hospital admission for IPD, particularly in European studies 1.

Herd Immunity

• Vaccination of children with pneumococcal conjugate vaccines has been shown to have a significant impact on reducing IPD in adults, particularly in the age groups of parents and grandparents, through herd immunity 1.

From the Research

Pneumococcal Vaccine Efficacy

• The 13-valent pneumococcal conjugate vaccine (PCV13) has been shown to be effective in preventing invasive pneumococcal disease (IPD) in adults, with a vaccine effectiveness of 61.5% against PCV13-serotype IPD 2.
• The introduction of PCV13 in children has also led to a decline in IPD incidence among adults, with a 57-74% reduction in PCV13-type IPD among adults with and without immunocompromising conditions 3.
• However, some studies have raised concerns about the limited effectiveness and immunogenicity of the 23-valent pneumococcal polysaccharide vaccine (PPV23) in high-risk populations, such as those with immunocompromising conditions and the elderly 4.

Newer Vaccines

• A 20-valent pneumococcal conjugate vaccine (PCV20) has been licensed for use in adults, which contains all components of PCV13 with the addition of polysaccharide conjugates of seven more serotypes 5.
• PCV20 has been shown to induce robust immune responses to all 20 S. pneumoniae serotypes covered by the vaccine and has a similar tolerability and safety profile to PCV13 5.

Impact of Vaccination

• The introduction of PCV13 into routine pediatric use has led to a significant reduction in IPD incidence among children, with an 84% decrease in PCV13-type IPD among children aged 6 weeks to <6 years 6.
• The impact of vaccination on IPD incidence has also been observed in adults, with a decline in IPD incidence after the introduction of PCV13 in children, suggesting both direct and indirect effects of vaccination 3, 6.