Adult Pneumococcal Hospitalizations Rise Despite New Vaccines

A preliminary IDWeek 2026 study found adults' serious pneumococcal infections rose 16% to 23% above baseline while children's stayed flat.

Updated on Nov. 3, 2026 in Diseases — General

Adult Pneumococcal Hospitalizations Rise Despite New Vaccines

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Have you kept up with your recommended pneumococcal vaccine shots as an adult?

A study presented at IDWeek 2026 found that hospitalizations for invasive pneumococcal disease (IPD) among U.S. adults rose during 2022 to 2024, even as higher-valency pneumococcal vaccines became available, while pediatric hospitalization rates stayed flat. The findings were drawn from commercially insured patients and are preliminary until peer-reviewed.

Why it matters

The results raise questions about how well newer pneumococcal vaccines are reducing serious infections in adults, a group that has become a larger share of hospitalizations. The findings were presented at a scientific meeting and have not yet been published in a peer-reviewed journal.

This retrospective study analyzed 204,479 IPD-associated hospitalizations in commercially insured patients from 2006 to 2024, comparing a 2006-2019 baseline with a 2022-2024 period when higher-valency vaccines were available. Adult hospitalization rates were 16% to 23% higher than baseline (IRR 1.16-1.23), while pediatric rates were essentially unchanged (IRR 0.96-1.05).

The players

IDWeek 2026

An annual infectious diseases scientific conference where the study results were presented in Washington, DC.

Merative MarketScan Commercial database

A commercial insurance claims database used to identify the commercially insured patients analyzed in the study.

The details

Researchers used generalized linear quasi-Poisson regression to compare hospitalization rates across age groups of 0-2, 3-17, 18-49, and 50-64 years. Patients aged 50 to 64 accounted for 54.4% of the hospitalizations, making that group the largest contributor to the overall count. The study compared periods when older pneumococcal vaccines (PCV7 and PCV13) were available with periods when newer, higher-valency vaccines (PCV15, PCV20, and PCV21) were in use, and excluded 2020 and 2021 because of the COVID-19 pandemic.

2006 to 2019: Baseline period, when PCV7 and PCV13 were available.
2022 to 2024: Higher-valency period, when PCV15, PCV20, and PCV21 were available.
October 21 to 24, 2026: Study results presented at IDWeek 2026 in Washington, DC.

Health Landscape

Pneumococcal vaccines have been expanded in valency over the past two decades to cover more bacterial serotypes, with PCV15, PCV20, and PCV21 now available alongside older formulations. This study provides a population-level check on whether that expansion has translated into fewer serious pneumococcal hospitalizations among adults.

Adults who are due for pneumococcal vaccination may want to ask their doctor which vaccine options fit their age and risk profile, since the study points to continued adult disease burden. Because these are preliminary findings from commercially insured patients, they should be weighed alongside current official vaccine guidance rather than used to change any personal vaccine plan on their own.

The takeaway

Adult pneumococcal disease hospitalizations rose in this analysis even as newer vaccines became available, a signal worth watching as peer-reviewed results emerge. Adults with questions about their pneumococcal vaccine status are encouraged to discuss their options with a physician.