Pneumococcal vaccine protecting elderly people from pneumonia.

Pneumococcal Vaccine: Are You Fully Protected?

Nico Varela in Health & Wellness December 2025 • 4 min read.

"A new study reveals a surprising gap in pneumococcal vaccination rates among older adults, highlighting the need for better awareness and adherence to recommended guidelines."

Pneumonia, often caused by the bacterium Streptococcus pneumoniae, poses a significant threat to older adults. This infection can lead to serious conditions, including invasive pneumococcal diseases (IPD), resulting in high morbidity, mortality, and healthcare costs. Vaccination is a key preventive measure, yet recent research suggests that many older adults may not be fully protected.

Two pneumococcal vaccines are currently licensed in the United States: pneumococcal conjugate vaccine (PCV13) and pneumococcal polysaccharide vaccine (PPV23). These vaccines protect against different serotypes of the bacteria, and since 2014, the Advisory Committee on Immunization Practices (ACIP) has recommended a sequential approach – PCV13 followed by PPV23 – for adults 65 and older.

A new study published in Vaccine examines pneumococcal vaccination patterns among adults aged 65 years or older in the United States. Using a large claims database, the researchers investigated vaccination rates, completion of the recommended series, time between doses, and factors associated with series completion. The findings reveal a concerning gap in adherence to vaccination guidelines, underscoring the need for improved strategies to protect this vulnerable population.

The Vaccination Gap: Key Findings on Pneumococcal Protection

Pneumococcal vaccine protecting elderly people from pneumonia.

The study, which analyzed data from over 224,000 adults, revealed that nearly half (49%) had not received any pneumococcal vaccination. Only 16.8% had completed the recommended PCV13-PPV23 series. This leaves a large proportion of older adults potentially vulnerable to pneumococcal disease.

Further analysis showed that among those who received only one vaccine, 22.7% received PCV13 and 11.6% received PPV23. The timing between vaccinations in those who completed the series also varied, with an average of 14 months between PCV13 and PPV23, and 20 months between PPV23 and PCV13.

Low Completion Rates: Only a small percentage of older adults are completing the recommended pneumococcal vaccination series.
Missed Opportunities: A significant number of adults are receiving only one of the two recommended vaccines, leaving them partially unprotected.
Timing Matters: The interval between doses can vary, with some individuals not receiving the second vaccine within the recommended timeframe.

The study also identified several factors associated with increased likelihood of series completion. These included frequent healthcare encounters (doctor's office visits, outpatient visits, pharmacy visits), receiving an influenza vaccine, residing in the North Central region of the US, and enrollment in a Health Maintenance Organization (HMO) plan.

Protecting Our Seniors: Steps to Improve Pneumococcal Vaccination Rates

These findings underscore the urgent need to improve pneumococcal vaccination rates among older adults. Increasing awareness of the ACIP recommendations, particularly the importance of completing the PCV13-PPV23 series, is crucial.

Healthcare providers play a vital role in educating patients about pneumococcal disease and the benefits of vaccination. Strategies to improve vaccination rates include standing orders, reminder systems, and co-administration of pneumococcal vaccines with other recommended adult vaccines (e.g., influenza vaccine).

Further research is needed to understand the barriers to pneumococcal vaccination in specific populations and to develop targeted interventions to address these challenges. By working together, healthcare providers, public health organizations, and individuals can help protect older adults from the serious consequences of pneumococcal disease.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.vaccine.2018.10.015, Alternate LINK

Title: Pneumococcal Vaccination Patterns Among Persons Aged 65 Years Or Older In The United States: A Retrospective Database Analysis

Subject: Infectious Diseases

Journal: Vaccine

Publisher: Elsevier BV

Authors: Xiaoqin Yang, Dongmu Zhang, Wanmei Ou

Published: 2018-11-01

Everything You Need To Know

What's the current recommended pneumococcal vaccine schedule for seniors?

The current recommendation from the Advisory Committee on Immunization Practices (ACIP) for adults 65 and older is a sequential approach using two pneumococcal vaccines: pneumococcal conjugate vaccine (PCV13) followed by pneumococcal polysaccharide vaccine (PPV23). This combined approach provides broader protection against different serotypes of the *Streptococcus pneumoniae* bacteria than either vaccine alone. Completing this series is crucial for optimal protection against pneumococcal disease.

What did the study reveal about how many seniors are actually fully vaccinated against pneumococcal disease?

The study highlights that many older adults are not fully protected against pneumococcal disease. Specifically, it found that nearly half (49%) of adults aged 65 years or older had not received any pneumococcal vaccination. Furthermore, only 16.8% had completed the full recommended series of PCV13 followed by PPV23. This leaves a significant portion of the older adult population vulnerable to pneumococcal infections and related complications, emphasizing the need for improved vaccination rates.

What factors make older adults more likely to complete the pneumococcal vaccine series?

Several factors seem to influence whether older adults complete the recommended pneumococcal vaccination series. The study identified that frequent healthcare encounters (such as doctor's office visits and pharmacy visits), receiving an influenza vaccine, residing in the North Central region of the United States, and enrollment in a Health Maintenance Organization (HMO) plan were all associated with a higher likelihood of completing the PCV13-PPV23 series. Understanding these factors can help healthcare providers target interventions to improve vaccination rates among those less likely to be fully vaccinated.

What is the difference between the pneumococcal conjugate vaccine (PCV13) and the pneumococcal polysaccharide vaccine (PPV23)?

Pneumococcal conjugate vaccine (PCV13) and pneumococcal polysaccharide vaccine (PPV23) differ in how they stimulate the immune system. PCV13 is a conjugate vaccine, meaning it links pneumococcal serotypes to a protein, which elicits a stronger immune response, particularly in older adults. This is because it can activate T-cells, leading to a longer-lasting immunity. PPV23, on the other hand, is a polysaccharide vaccine composed of purified capsular polysaccharides of 23 serotypes of *Streptococcus pneumoniae*. It stimulates B-cells directly, but the immune response may not be as robust or long-lasting, especially in older adults whose immune systems may be weaker. Hence the recommendation for PCV13 first.

Why is it recommended to get PCV13 first and then PPV23 when getting vaccinated against pneumococcal disease?

The sequential approach of administering PCV13 first, followed by PPV23, aims to provide comprehensive and long-lasting protection against pneumococcal disease. PCV13 primes the immune system and elicits a T-cell dependent response, leading to better immunological memory. Administering PPV23 after PCV13 broadens the coverage against additional pneumococcal serotypes not included in PCV13. The timing is important as well, as the immune response from PPV23 is enhanced when preceded by PCV13. The study indicates that many individuals do not follow this sequence, leading to reduced protection.