Pneumonia vaccine protection

Pneumonia Protection: Are You Getting the Right Shots?

Rhea Morgan monogram
Rhea Morgan in Health & Wellness November 2026 • 4 min read.

"Understanding PCV13 and PPV23 Vaccines for Adults at Risk"


Pneumonia is a serious infection of the lungs that can lead to hospitalization and even death, especially for older adults and those with underlying health conditions. Fortunately, vaccines are available to help protect against pneumococcal pneumonia, the most common type of bacterial pneumonia.

Two main vaccines are used to prevent pneumococcal pneumonia: the 13-valent pneumococcal conjugate vaccine (PCV13) and the 23-valent pneumococcal polysaccharide vaccine (PPV23). While both vaccines protect against different strains of the bacteria, understanding their specific benefits and who should receive them is crucial.

This article aims to provide a clear and concise overview of PCV13 and PPV23, focusing on the latest research and recommendations for adults at increased risk of pneumococcal disease. We'll break down the key findings from recent studies presented at scientific conferences, offering practical insights to help you make informed decisions about your health.

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Pneumonia’s U.S. Burden

In 2022, 23.9% of U.S. adults aged 18 and older reported ever receiving a pneumococcal vaccination. In 2021, pneumonia due to an infectious organism was the primary diagnosis for 1.4 million emergency department visits, and the CDC reports 41,309 deaths. CDC surveillance also reports that invasive pneumococcal disease rates declined dramatically among children and adults after pneumococcal conjugate vaccines began being used in the United States in 2000; infections are more common in winter and early spring.

Adult Vaccine Options and Guidance

The CDC’s 2023 report compiles ACIP recommendations for pneumococcal vaccines in U.S. adults aged 19 years and older. Before 2021, ACIP recommended PPSV23 alone, up to two doses, or PCV13 combined with one to three doses of PPSV23 in some adult vaccination strategies. Pneumococcal disease is caused by some of the more than 90 serotypes of Streptococcus pneumoniae, while vaccines target many, rather than all, disease-causing serotypes. A 2015 study reported that the efficacy of pneumococcal conjugate vaccines against pneumococcal community-acquired pneumonia in adults aged 65 years or older was uncertain.

More Than a Century of Vaccine Development

A 2022 review describes the development of pneumococcal vaccines and the effects of different vaccines and vaccination strategies over the past 111 years. A separate account reports that early vaccination reduced pneumonia caused by vaccine-specific strains, but recipients were followed for only two to three months, so long-term effectiveness was not determined. Together, these sources trace a long history while noting that early evidence had a limited follow-up period.

PCV13 vs. PPV23: Which Pneumonia Vaccine is Right for You?

Pneumonia vaccine protection

Both PCV13 (Prevnar 13) and PPV23 (Pneumovax 23) are designed to protect against pneumococcal disease, but they work differently and target different populations. PCV13 protects against 13 types of pneumococcal bacteria, while PPV23 protects against 23 types. The Advisory Committee on Immunization Practices (ACIP) recommends specific use cases for each vaccine based on age and health conditions.

A study highlighted at a recent infectious disease conference examined the uptake of PCV13 among high-risk adults aged 19-64 years following the ACIP's 2012 recommendation. The study, using data from both administrative health claims and electronic health records, revealed surprisingly low vaccination rates: less than 15% of recommended high-risk patients received PCV13 in the four years after the recommendation.

  • High-Risk Groups: Adults with conditions like diabetes, heart disease, lung disease, and a weakened immune system are at higher risk for pneumococcal disease.
  • Low Uptake: The study indicated that many at-risk adults are not receiving the recommended PCV13 vaccine, potentially leaving them vulnerable to infection.
  • Spillover Effect: Interestingly, the study noted that vaccination rates among this high-risk group increased slightly after the 2014 recommendation for all adults aged 65 and older, suggesting a "spillover effect" where increased awareness benefited younger at-risk individuals.
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Evidence on PCV13 and Newer Vaccines

A systematic literature review describes observational studies evaluating PCV13 effectiveness across epidemiologic and geographic settings after a decade of pediatric use. A 2025 study reports that PCV13 has demonstrated substantial efficacy against overall and non-bacteremic vaccine-type community-acquired pneumonia in older adults. A 2025 review notes that PCV21 became available that year, alongside PCV15 and PCV20, prompting reconsideration of adult pneumococcal pneumonia prevention strategies.

Breakthrough Infections and Evidence Gaps

A 2026 study says vaccine failures and breakthrough infections have not been systematically studied in Belgium. It aims to establish a baseline by characterizing these cases in children aged 0–5 during the recent PCV13 era, ahead of PCV20 introduction. A separate review reports that pediatric PCV7 use dramatically reduced pneumococcal disease in vaccinated children and unvaccinated people of all ages, illustrating both vaccine impact and the importance of assessing population-level effects.

How Pneumococcal Vaccine Options Evolved

The first U.S. pneumococcal vaccine, approved in 1977, contained purified capsular polysaccharide antigens from 14 serotypes. Six years later, the 23-valent polysaccharide vaccine PPSV23 (Pneumovax 23) was approved, replacing the 14-valent vaccine. A comparison document lists PPSV23, PCV13 (Prevnar 13), and the conjugate vaccines PCV20 (Prevnar 20) and PCV15 (Vaxneuvance), which were approved in 2021, among adult options.

Another study presented at the conference explored the cost-effectiveness of PCV13 compared to PPV23 in the Netherlands. The research used a sophisticated model to assess the value of vaccinating specific age and risk groups. Results showed that vaccinating all adults at increased risk with PCV13 was cost-effective, but the most value for money came from targeting individuals with underlying diseases aged less than 85 years. In particular, vaccinating high-risk individuals under 65 with PCV13 was actually cost-saving compared to PPV23.

Take Control of Your Pneumonia Risk

Pneumonia can be a serious threat, but vaccination offers a powerful defense. Talk to your doctor about whether PCV13 or PPV23 is right for you, especially if you are over 65 or have underlying health conditions. By staying informed and taking proactive steps, you can protect yourself and your loved ones from the risks of pneumococcal disease.

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Evidence on Protection in Adults

A 2023 systematic review and meta-analysis examined randomized trials and observational studies of PCV13 and PPSV23 against vaccine-type invasive pneumococcal disease and pneumococcal pneumonia in adults. Its reported findings suggest that both vaccines protect against vaccine-type invasive disease and vaccine-type pneumococcal pneumonia, while noting heterogeneity across studies. An expert review reports that PCV13 had a favorable safety profile and that CAPiTA demonstrated efficacy for at least five years against vaccine-type invasive pneumococcal disease.

Recommendations and Next-Generation Vaccines

The Advisory Committee on Immunization Practices updated adult pneumococcal vaccine recommendations in October 2022, the fifth update since 2012. The stated goals were to increase population-level protection and reduce disparities in disease burden among people at increased risk. A 2026 Medscape report describes updated recommendations for adults aged 50 and older and next-generation vaccines as emerging areas in pneumococcal disease prevention.

Real-World Effectiveness in Adults

A 2025 study examined the clinical effectiveness of PCV13 and PPSV23, noting that evidence for preventing pneumococcal and all-cause pneumonia in adults is limited and inconsistent despite recognized benefits against vaccine-type infections. A 2018 study reported real-world effectiveness of PCV13 against vaccine-type community-acquired pneumonia in adults aged 65 years and older after its introduction into a national immunization program. These findings address different outcomes and study settings, so they do not resolve the uncertainty about protection against all-cause pneumonia.

PCV13 results depend on which pneumonia outcome is counted

  • 45.6% efficacyIn the CAPiTA trial, PCV13 efficacy against vaccine-type pneumococcal pneumonia was 45.6% compared with placebo, but efficacy against all-cause pneumonia was not significant.[1]Caveat: No significant efficacy against all-cause pneumonia, death from pneumonia, or all-cause death
  • 47%–59%; 38%–70%; 6%–11% effectivenessPostlicensure estimates for PCV13 effectiveness were 47%–59% against vaccine-type invasive disease and 38%–70% against noninvasive vaccine-type pneumonia; estimates against all-cause pneumonia were 6%–11%.[2]

Protection looks different by outcome and population

The results distinguish protection against pneumonia caused by vaccine-covered types from protection against pneumonia of any cause. A positive estimate for the narrower outcome does not establish a significant benefit for all-cause pneumonia or deaths.[1] [2]

The broad confidence interval around the PPSV23 estimate spans both possible benefit and possible lack of benefit, so that estimate alone does not settle how well it prevents vaccine-type pneumonia in older adults.[3]

Trial setting and outcome definitions shape the comparisons

The CAPiTA trial took place in a country with low pneumococcal pneumonia incidence and high uptake of childhood PCV7, followed by PCV10; those conditions may have affected the observed vaccine-effectiveness magnitude.[4]

CAPiTA had too few participants who developed immunosuppression after vaccination, and too few in older cohorts, to draw efficacy conclusions for those groups. Its overall results therefore do not resolve effectiveness in those subpopulations.[4]

A Spanish analysis could not identify pneumococcal serotypes in its administrative data, preventing it from assessing effectiveness against vaccine-type pneumonia. That outcome gap makes its findings less specific to vaccine-targeted disease than serotype-based measures.[5]

What future comparisons would need to clarify

  • How well do vaccine-effectiveness estimates transfer from low-incidence settings with extensive childhood vaccination to populations with different disease patterns?[4] [6]
  • What protection can be established for people who become immunosuppressed after vaccination and for older cohorts that were too small to assess?[4]
  • How would serotype-level data change estimates that currently cannot separate vaccine-type pneumonia from pneumonia caused by other types?[5]

Sources

  1. Evaluating clinical effectiveness of 13-valent pneumococcal conjugate vaccination against pneumonia among middle-aged and older adults in Catalonia: results from the EPIVAC cohort study (pmc.ncbi.nlm.nih.gov)
  2. Use of 13-Valent Pneumococcal Conjugate Vaccine and 23-Valent Pneumococcal Polysaccharide Vaccine Among Adults Aged ≥65 Years: Updated Recommendations of the Advisory Committee on Immunization Practic (pmc.ncbi.nlm.nih.gov)
  3. Systematic Review and Meta-Analysis of the Efficacy and Effectiveness of Pneumococcal Vaccines in Adults (pmc.ncbi.nlm.nih.gov)
  4. Prevention of adult pneumococcal pneumonia with the 13-valent pneumococcal conjugate vaccine: CAPiTA, the community-acquired pneumonia immunization trial in adults (pmc.ncbi.nlm.nih.gov)
  5. Evaluating clinical effectiveness and impact of anti-pneumococcal vaccination in adults after universal childhood PCV13 implementation in Catalonia, 2017–2018 (pmc.ncbi.nlm.nih.gov)
  6. PCV13 Vaccination of Adults against Pneumococcal Disease: What We Have Learned from the Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA) (pmc.ncbi.nlm.nih.gov)

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

Everything You Need To Know

1

What is pneumococcal pneumonia and why is it a concern?

Pneumococcal pneumonia is a serious infection of the lungs, particularly dangerous for older adults and those with existing health problems. The severity of this condition can lead to hospitalization or even death, making it essential to consider preventive measures like vaccination. Understanding the risks associated with pneumococcal pneumonia underscores the importance of proactive health decisions, such as consulting with your doctor about appropriate vaccinations.

2

What are the differences between PCV13 and PPV23?

PCV13, or the 13-valent pneumococcal conjugate vaccine, protects against 13 strains of the pneumococcal bacteria. PPV23, the 23-valent pneumococcal polysaccharide vaccine, offers protection against 23 strains. Both vaccines are designed to prevent pneumococcal disease, but they achieve this protection through different mechanisms and target distinct populations. The ACIP (Advisory Committee on Immunization Practices) provides specific guidelines on which vaccine is most appropriate, based on age and health conditions.

3

Who is considered at higher risk for pneumococcal disease?

Adults with conditions like diabetes, heart disease, lung disease, or weakened immune systems are at higher risk for pneumococcal disease. The studies showed that many individuals in these high-risk groups are not receiving the recommended PCV13 vaccine. This is a concern because these individuals are more vulnerable to severe complications from pneumococcal pneumonia. Being aware of these risks and discussing them with your healthcare provider is vital for those with underlying health conditions.

4

What is the 'spillover effect' in the context of these vaccines?

The spillover effect refers to how increased awareness and uptake of PCV13 among adults aged 65 and older positively influenced vaccination rates in younger, at-risk adults. When the recommendation for PCV13 vaccination expanded to include all adults aged 65 and older in 2014, it led to a slight increase in vaccination rates among high-risk individuals aged 19-64. This suggests that broader public health initiatives can benefit a wider range of individuals, underscoring the interconnectedness of public health strategies.

5

What did the cost-effectiveness study reveal about PCV13 and PPV23?

The cost-effectiveness study in the Netherlands indicated that vaccinating high-risk adults with PCV13 was a cost-effective strategy. The most cost-effective approach was vaccinating individuals with underlying diseases who are under 85 years old. Furthermore, vaccinating high-risk individuals under 65 with PCV13 was actually cost-saving compared to PPV23. This analysis provides a valuable perspective on the financial implications of different vaccination strategies, highlighting the potential for PCV13 to be a cost-effective means of preventing pneumococcal disease, especially in vulnerable populations.

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