PCV20 Demonstrates Real-World Effectiveness Against Pneumonia in Older Adults

A new analysis presented at IDWeek 2025, which took place from October 19 to October 22, 2025, in Atlanta, GA, demonstrates real-world vaccine effectiveness of the 20-valent pneumococcal conjugate vaccine (PCV20) against invasive pneumococcal disease (IPD) and all-cause pneumonia (ACP) in adults aged 65 to 74, 75 to 84, and 85 years and older.¹

Background on PCV20

Pneumococcal vaccines have continued their evolution over the past decade, with newer vaccines protecting against more serotypes of Streptococcus pneumoniae. In the United States, 15-valent PCV (PCV15), PCV20, and 21-valent PCV (PCV21) are all approved for use and recommended for children younger than 5 years and adults 50 years or older. Children and adults at increased risk for pneumococcal disease are also encouraged to be vaccinated.²

Since the FDA licensed PCV20 in 2021, there have been little clinical efficacy or vaccine effectiveness (VE) data reported. The current investigators sought to fill this research gap by evaluating age-group PCV20 VE against all IPD and ACP among older adults in the US. The retrospective time-segment design study enrolled individuals from the Medicare database from July 2022 to June 2024.¹

Was PCV20 Effective in Real-World Settings?

Individuals vaccinated with PCV20 were compared to unvaccinated adults who had Medicare insurance for at least 1 year or longer prior to the first episode of IPD and ACP. Individuals who received the 23-valent pneumococcal polysaccharide vaccine (PPSV23) within the last 2 years, 13-valent PCV (PCV13) within the last 5 years, PCV 20, or PCV15 prior to the start of study follow-up were excluded from the analysis.¹

A total of 16.5 million adults were included and stratified by age group, of whom 12.2% received PCV20 during the follow-up period. Following weighting and compared with individuals with PCV20-unvaccinated segments, there was a higher proportion of individuals contributing vaccinated time with 5 or more outpatient visits in the past year. These individuals also had previously received PPSV23, PCV13, or a COVID-19 vaccine within the year.¹

VE induced by PCV20 against all IPD was 25.6% among adults aged 65 and older overall and 35.4%, 24.0%, and 16.6% among adults aged 65 to 74, 75 to 85, and 85 and older, respectively. For ACP, PCV20 VE was 15.2% among adults aged 65 and older overall and 20.2%, 15.9%, and 12.5% among adults aged 65 to 74, 75 to 84, and 85 and older, respectively, according to the investigators.¹

What Should Pharmacists Know?

PCV20 vaccination prevented 12.5 cases of IPD and 262.0 cases of ACP per 100,000 person-years. This signifies PCV20’s broad effectiveness at preventing disease in a population of older adults over time while accounting for varying follow-up periods among the study participants.¹

These results affirm the protective benefits of PCV20 beyond clinical trial settings. VE differs from vaccine efficacy in that it determines how well vaccines work in the real-world. Despite clinical trials including a host of individuals from various backgrounds, they still cannot perfectly represent the whole population. Therefore, in this population of older adults, PCV20 prevented 25.6% of IPD cases and 15.2% of ACP cases that would have occurred if not for the vaccine.^1,3

Pharmacists play an integral role in continuing to advocate for pneumococcal vaccination. Patients at risk for IPD or ACP or who fall into the CDC’s age-based recommendations should be encouraged by their pharmacist to consider vaccination. Meanwhile, pharmacists should stay up to date on updates regarding VE for pneumococcal vaccines.¹

REFERENCES

1. Miles AC, Grant L, Vojicic J, Vietri JT, et al. P-1428: Real-world effectiveness of 20-valent pneumococcal conjugate vaccine among adults 65-74, 75-84, and ≥ 85 years of age in the United States. Presented: IDWeek 2025; October 21, 2025; Atlanta, Georgia. Accessed October 30, 2025 via IDWeek’s online conference platform.

2. Pneumococcal disease—pneumococcal vaccine recommendations. CDC. Last Updated October 26, 2024. Accessed October 30, 2025. https://www.cdc.gov/pneumococcal/hcp/vaccine-recommendations/index.html

3. Vaccine efficacy, effectiveness and protection. World Health Organization. Published March 10, 2025. Accessed October 30, 2025. https://www.who.int/news-room/feature-stories/detail/vaccine-efficacy-effectiveness-and-protection