Pneumonia prevention strategies need to be redesigned for the elderly

Pneumonia, the third leading cause of death…disease burden in older adults continues to rise

Adult NIP remains underserved…calls grow for institutional reform, including finer age segmentation

As pneumonia emerges as a major disease that simultaneously causes death and functional decline in older adults, the need to redesign prevention strategies is growing.

In particular, since the prognosis following pneumonia is more severe in older adults, there is a call to shift from a treatment-centered approach after diagnosis to a focus on prevention.

Chang-oh Kim, Professor of Geriatric Medicine at Severance Hospital

In a recent interview with DailyPharm, Professor Chang-oh Kim of the Division of Geriatrics at Severance Hospital discussed the clinical risks of pneumonia in older adults, changes in vaccine strategy, and the need to improve the National Immunization Program (NIP).

According to Statistics Korea, pneumonia was the third leading cause of death in Korea in 2024, following cancer and heart disease.

Given the rapidly aging demographic structure of the country, the disease burden of pneumonia is likely to increase further in the future.

In particular, pneumococcal infections carry a high risk of progressing to severe illness in older adults. It is known that the mortality rate from pneumococcal bacteremia among those aged 65 and older is approximately 60%, while meningitis reaches 80%. Even among survivors, there are numerous cases where neurological sequelae or functional impairment persist.

Despite this burden, the adult immunization system remains limited. In the Korea Disease Control and Prevention Agency’s prioritization assessment for vaccines to be included in the national program, the pneumococcal vaccine ranked highly for those aged 65 and older, but that priority has not yet been sufficiently reflected in the actual system.

Currently, Korea has approved 23-valent polysaccharide vaccine (PPSV23) and 13-, 15-, 20-, and 21-valent protein conjugate vaccines (PCV). In its 2025 recommendations, the Korean Society of Infectious Diseases recommends either a single PCV20 dose or sequential PCV15 and PPSV23 vaccination in adults aged 65 and older and in high-risk groups. This is interpreted as a trend toward reorganizing prevention strategies to focus on serotypes with a high disease burden.

Need to expand adult NIP rises… ‘Finer age segmentation also proposed as an option’

Professor Kim explains that despite changes in pneumococcal prevention strategies, the institutional framework has not fully reflected these changes.

According to Professor Kim, while protein-conjugated vaccines are systematically administered to children through the National Immunization Program (NIP), the system for adults still relies on out-of-pocket payments. This has created a blind spot where adult vaccination is pushed down the priority list.

Professor Kim pointed out, “Adult vaccination lies in a blind spot both institutionally and in terms of awareness. Policy support is needed so that prevention can be naturally incorporated into a treatment-centered healthcare structure.”

He particularly stressed the need for a more finely segmented age-based approach. Professor Kim explained that while older adults are currently defined as those aged 65 and older, in actual clinical practice, functional decline often becomes distinctly apparent after the mid-70s.

Professor Kim said, “While the number of vaccines intended for inclusion in the NIP is continuously increasing, financial limitations also exist. In that respect, a more realistic approach would be to segment age criteria more finely.”

He added, “Considering the disease burden, hospitalization rate, severity, and functional decline in older adults, the social and economic benefits that can be gained through vaccination are substantial. We need to more actively consider expanding adult NIP. 

“Pneumonia in older adults: the problem lies after onset, not in diagnosis”

Professor Kim defined pneumonia in older adults not as a simple infectious disease but as “a disease that can lead to risk of death and long-term functional decline.”

In older adults, age-related decline in immune function acts as a basic vulnerability factor. As immune defenses weaken, pathogens such as pneumococcus can invade more easily, and even after infection, the inflammatory response cannot be effectively controlled, making severe progression more likely. The risk is further exacerbated by the presence of various underlying conditions, such as diabetes, cardiovascular disease, and chronic lung disease.

The nonspecific nature of clinical symptoms is also cited as a problem.

Professor Kim explained, “In elderly patients, typical pneumonia symptoms like fever or cough often do not appear; instead, they frequently seek medical care due to impaired consciousness or generalized weakness. As a result, delays in diagnosis and treatment are common.”

Aspiration risk due to impaired swallowing function is also a major factor. Food or secretions can enter the airway and lead to aspiration pneumonia, which further increases disease severity.

Above all, functional decline after recovery remains a major issue. Even if the infection itself improves, many patients experience reduced muscle strength and physical function, leading to a significant decline in their ability to perform activities of daily living, and many do not recover to their prior state.

Kim emphasized, “In older adults, the prognosis following the onset of pneumonia is more critical than the pneumonia itself. This is why we must shift from a treatment-centered to a prevention-centered approach.”

He added, “The key in pneumococcal prevention is not only preventing what happens after invasive infection occurs, but also reducing pneumonia itself by suppressing bacterial colonization and transmission at the mucosal stage.”

He also mentioned changes in vaccine strategy. Recently, prevention strategies have evolved with the emergence of vaccines such as the 20-valent pneumococcal conjugate vaccine (Prevnar 20) that offers expanded serotype coverage. Compared with PCV13, PCV20 includes seven additional serotypes—8, 10A, 11A, 12F, 15B, 22F, and 33F—selected with consideration of invasive disease potential, disease severity, and antibiotic resistance.

Professor Kim explained, “In the past, polysaccharide vaccines garnered attention due to the large number of serotypes they covered, but today, reducing infections through mucosal immunity has become more important. Protein-conjugated vaccines have now advanced to a stage where they can sufficiently fulfill this role.”

He continued, “Considering these factors, the Korea Society of Infectious Diseases also recommends the 20-valent vaccine, and I believe discussions on improving the National Immunization Program (NIP) should be made based on these recommendations.”

Korean studies have also shown that about 51% of adult invasive pneumococcal disease is caused by serotypes included in PCV20, supporting the importance of prevention strategies that reflect the actual disease burden.

Professor Kim emphasized, “There are more than 100 pneumococcal serotypes, but what matters is not the number but how many of the serotypes with a high disease burden are covered. If dominant serotypes are covered, even a limited number of serotypes can prevent a significant portion of all infections.”