23-valent pneumococcal polysaccharide vaccine

23-valent pneumococcal polysaccharide vaccine has been studied in 6 papers since 2023: 6 observational studies in people; 2 in the past year. The newest story, Oct 26, 2026: “Pneumococcal vaccination linked to fewer deaths in older adults”.

Intervention

6 papers study it6 findingsUpdated Oct 2, 2026

1 new paper in 30 daysSee all 6

“PPSV23 vaccination reduced all-cause mortality (VE = 43.1%, 95% CI: 41.2-45.0%)”

Effectiveness of the 23-Valent Pneumococcal Polysaccharide Vaccine in Reducing Mortality Among Older Adults: A Real-World Retrospective Cohort Study in Guangzhou, ChinaVaccines2026doi:10.3390/vaccines14100877

None of its findings points the other way.

3 independent labs in 2 countries
2 trials, none about aging

Funders: Project for Key Medicine Discipline Construction of Guangzhou Municipality and 7 more

Humans6

What is 23-valent pneumococcal polysaccharide vaccine linked with?

Studies link 23-valent pneumococcal polysaccharide vaccine with 6 measures, most often COPD-related mortality (1 study), pneumonia-related mortality (1) and mortality (1).

COPD-related mortality

downin humans1

1 study

23-valent pneumococcal polysaccharide vaccine is associated with COPD-related mortality in humans (VE 33.5% (95% CI 20.9–44.2%); all p < 0.001).
“PPSV23 vaccination was associated with significantly lower all-cause, pneumonia-related, and COPD-related mortality among elderly individuals aged ≥60 years.”
Humansmean follow-up 5.61 yearsn = 453,500
Pneumococcal vaccination linked to fewer deaths in older adults
VaccinesOct 2, 2026

Pneumonia-related mortality

downin humans1

1 study

23-valent pneumococcal polysaccharide vaccine is associated with pneumonia-related mortality in humans (VE 46.2% (95% CI 39.6–52.1%); all p < 0.001).
“PPSV23 vaccination was associated with significantly lower all-cause, pneumonia-related, and COPD-related mortality among elderly individuals aged ≥60 years.”
Humansmean follow-up 5.61 yearsn = 453,500
Pneumococcal vaccination linked to fewer deaths in older adults
VaccinesOct 2, 2026

Mortality

downin humans1

1 study

23-valent pneumococcal polysaccharide vaccine is associated with mortality in humans (VE 43.1% (95% CI 41.2–45.0%); all p < 0.001).
“PPSV23 vaccination reduced all-cause mortality (VE = 43.1%, 95% CI: 41.2-45.0%)”
Humansmean follow-up 5.61 yearsn = 453,500
Pneumococcal vaccination linked to fewer deaths in older adults
VaccinesOct 2, 2026

Hospitalization with pneumonia

downin humans1

1 study

23-valent pneumococcal polysaccharide vaccine is linked with a lower risk of hospitalization with pneumonia in humans (sHR 0.84, 95% CI 0.77-0.91).
“Overall, PPV23 administration was associated with a decreased incidence of hospitalization with pneumonia (17.2 vs. 20.4 per 1000 person-years, sub-distribution hazard ratio: 0.84, 95% CI: 0.77 to 0.91).”
Humans
Effect of the 23-valent pneumococcal polysaccharide vaccine on the incidence of hospitalization with pneumonia in adults aged ≥65 years: retrospective cohort study using a population-based database in Japan
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious DiseasesApr 10, 2023

Stroke

downin humans1

1 study

23-valent pneumococcal polysaccharide vaccine is linked with a lower risk of stroke in humans (compared with unvaccinated individuals) (aOR 0.81 (95% CI 0.77-0.86)).
“and aOR, 0.81 [95% CI, 0.77-0.86], respectively).”
Humanscompared with unvaccinated individuals
Association of pneumococcal vaccination with cardiovascular diseases in older adults: The vaccine effectiveness, networking, and universal safety (VENUS) study
VaccineMar 2, 2023

Who is developing 23-valent pneumococcal polysaccharide vaccine?

1 company: Merck Sharp & Dohme.

Companies: Merck Sharp & DohmePhase 3pneumococcal infection

Trial sponsors

Merck & Co.
Company1 trialPhase 3850 people
The First Affiliated Hospital of Guangzhou Medical University
1 trialPhase 41,278 people

Latest

2 papers in 12 months

VaccinesOct 26

Pneumococcal vaccination linked to fewer deaths in older adults

Vaccination was associated with 43.1% lower overall mortality relative to no vaccination among 453,500 adults aged 60 and older.Vaccination was associated with 43.1% lower overall mortality relative to no vaccination among 453,500 adults aged 60 and older.

Cohort · 453,500 peopleInterventions