Pneumonia has early symptoms such as cough and fever that are similar to those of a common cold, making early recognition and response difficult and making it hard for patients to perceive warning signs. In particular, among older adults, pneumonia can rapidly progress to a severe stage in a short period, and in many cases, patients are unable to communicate the subsequent risk to those around them. The dead tell no tales.

In fact, as of 2024, pneumonia is a fatal disease that ranks as the third leading cause of death in Korea, along with cancer and heart disease. It is far more lethal than influenza, which is rarely recorded as a sole cause of death. Mortality rates increase sharply from people in their 50s and older. The pneumonia mortality rate per 100,000 population rises steeply from 5.9 in those in their 50s to 953.5 in those in their 80s. Among people in their 80s, more than 1 in 10 die from pneumonia.

The main causative pathogen of pneumonia is pneumococcus, which accounts for up to 69% of cases. Pneumococcal infection can cause not only pneumonia but also invasive diseases such as meningitis, leaving serious neurological sequelae even in survivors. In diseases with distinct pain symptoms, such as herpes zoster, the pain itself serves as a warning signal, and the patient’s experience naturally leads to heightened awareness. Acute pain is known to strongly draw attention, prompt recognition of threat, and induce protective behavior.

In contrast, pneumonia does not have prominent pain at the initial stage, and the disease quickly progresses to a severe condition, making it difficult for patient experiences to be socially shared. As a result, despite being a life‑threatening disease, public perception of its risk tends to be lower than the actual risk. In infectious diseases, risk perception is heavily influenced by personal or vicarious experience, so this “lack of tangible experience” becomes a factor that creates a perception gap.

The World Health Organization (WHO) defines risk communication as “the real‑time exchange of information, advice and opinions between experts, officials and people who face a threat to their health, economic or social well‑being.” Its goal is to help the public choose behaviors that reduce risk. However, because the social sharing of patient experiences is structurally limited in the case of pneumonia, the process of “risk perception formation,” which is most crucial in public health, does not easily occur naturally.

Research in infectious diseases has also shown that lower risk perception is associated with lower vaccination rates. Therefore, for diseases like pneumonia, where it is difficult for individuals to personally feel the risk, the state must first recognize the danger and design preventive policies. The National Immunization Program (NIP) is the most effective public policy tool to bridge this perception gap and provide the population with real opportunities for prevention.

Among older adults, pneumococcal infection is a major health threat directly linked to life, going beyond a simple disease burden. Reflecting these disease characteristics, the guideline of the Korean Society of Infectious Diseases recommends the use of pneumococcal conjugate vaccines (PCVs), which have a broad serotype coverage and superior immunogenicity (the ability to elicit an immune response). In priority studies on the introduction of vaccines into the NIP conducted by the Korea Disease Control and Prevention Agency, PCV‑based vaccination has also been presented as a high priority.

However, in the current adult NIP, only the polysaccharide vaccine (PPSV23), introduced in 1983, is provided, and it has limitations such as inconsistent preventive effectiveness and a short duration of protection. PPSV23 has structural constraints that result in poor immune persistence. Simply put, even if a person is vaccinated, the body easily “forgets” pneumococcus over time, causing protection to decline rapidly and making infection more likely upon re‑exposure. This characteristic can be particularly problematic among older adults with weaker immune responses.

By contrast, PCV is a next‑generation vaccine that conjugates pneumococcal antigens to proteins. Studies to date have demonstrated that it induces a stronger and longer‑lasting immune response and, with its broader serotype coverage, offers superior preventive effectiveness. The protein conjugation acts as a kind of “memory‑stimulating device,” prolonging immunity and producing a stronger response upon revaccination. Nevertheless, PCV has not yet been included in the adult NIP, resulting in limited accessibility and differences in vaccination rates according to income level, thereby undermining equity in preventive benefits.

Under the current NIP framework, which provides only an older‑generation vaccine, it is difficult to sufficiently prevent pneumonia in older adults. Despite the existence of more effective vaccines, institutional constraints create gaps in which those in need do not receive timely protection. To protect the public from pneumonia, an “invisible disease,” it is necessary to expand PCV‑centered public preventive policies grounded in scientific evidence of effectiveness, so that older adults can be vaccinated without financial or access burdens.

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