Pneumococcal Disease EU

CME

Pneumococcal Disease: Current Concepts for At-Risk Adults

Physicians: Maximum of 0.75 AMA PRA Category 1 Credit

Released: August 22, 2024

Expiration: August 21, 2025

Elisabeth Botelho-Nevers
Elisabeth Botelho-Nevers, MD, PhD, HDR

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Serotypes Targeted by Pneumococcal Vaccines

Improving the approval and scheduling of pneumococcal vaccines is crucial to harnessing the benefits observed with conjugate vaccines, which have significantly impacted herd immunity over the years.20,21

However, we have also witnessed an increase in both invasive and noninvasive pneumococcal diseases caused by serotypes not covered by current vaccines, highlighting the necessity for further vaccine development.19

The table shows the variety of serotypes targeted by pneumococcal vaccines. The PCV13 vaccine covers 13 serotypes, the PCV15 vaccine covers the same serotypes as PCV13 plus 2 additional serotypes relevant for the pediatric population, and the PCV20 vaccine covers an additional 7 serotypes beyond PCV13. In addition, there is a 23-valent polysaccharide vaccine, PPSV23, which covers different serotypes.

The selection of additional serotypes in newer vaccines is based on their contribution to IPD, as some serotypes have been associated with higher mortality rates and reduced antibiotic sensitivity.10,19

Until recently, guidelines in most European countries recommended PCV13 and PPSV23 for adults.22 However, recommendations are evolving due to the superior immunogenicity conferred by conjugate vaccines and the approval of PCV20 .22,23

Serotype Coverage With PCV7, PCV13, and PCV20

Due to the need for increased vaccine coverage and the success of conjugate vaccines, PCV20 has been developed, building on the success of PCV7 and PCV13. PCV20 has the same formulation as PCV13 and has received recommendations and market authorization from both the US FDA and the European Medicines Agency. These approvals are based on immunobridging studies, and based on clinical efficacy demonstrated in anterior conjugate vaccines .1,24

PCV20 Immunogenicity

In a randomized, double-blind phase II study examining the immunogenicity of PCV20, PCV20 was compared to PCV13 followed by PPSV23 1 month later. The opsonophagocytic activity (OPA) levels of antibodies were similar in both groups, indicating comparable immunogenic responses to all serotypes. Safety of PCV20 was also demonstrated. These findings supported the phase III development and subsequent market authorization of PCV20 by governing bodies and medical agencies, expanding protection against pneumococcal disease, particularly in older adults.25

PCV20: Immunogenicity in Adults With Chronic Conditions or Who Smoke

Similarly, in people with chronic medical conditions or those who smoke, strong immune response and increased antibody levels have been observed after administration of PCV20. The immunogenicity is strong among individuals with chronic conditions, showing an increase in OPA geometric mean titers and a robust immune response to all 20 serotypes in the vaccine.26

Cost-Effectiveness of Pneumococcal Vaccination in Older Adults in England

It is essential to assess the impact and reduction of IPD and determine if vaccination is cost-effective.

An economic modeling study conducted in the UK compared the cost-effectiveness of PPSV23 to the newer conjugate vaccines, PCV15 or PCV20, in adults aged 65 or 75 years.

We can observe that vaccinating individuals aged 65 years or older is more cost-effective than vaccinating younger individuals. In most countries, vaccinations are recommended at age 65, emphasizing the cost-effectiveness associated with widespread vaccination.

The analysis found that at the listed prices of PCV20 and PPSV23 as of May 2023, both were cost-effective when vaccinating 65- or 75-year-olds with an Institute for Clinical and Economic Review threshold of £20,000 per QALY. The study also concluded that PCV20 is projected to prevent more cases of pneumococcal disease among elderly adults in England compared to the current PPSV23 vaccine, based on assumptions of higher vaccine effectiveness and slower waning of protection for PCV20.27