Community vaccination program reduces pneumonia deaths among the elderly in Japan

Community vaccination program reduces pneumonia deaths among the elderly in Japan

A research team evaluated the real-world impact of a community-based pneumococcal vaccine support program for older adults in Hiroshima Prefecture, Japan.

Your work will be published in theJournal of Epidemiologyon May 5, 2025.

Pneumonia is a leading cause of death in Japan. About 74,000 people die from pneumonia each year, with 98 percent of those deaths occurring in people age 65 and older. The bacteriaStreptococcus pneumoniaeis the main cause of pneumonia.

In October 2014, Japan launched a nationwide routine vaccination program for the elderly under the National Immunization Program with the 23-valent pneumococcal polysaccharide vaccine (PPSV23).

Sera Town, a mountainous community in Eastern Hiroshima Prefecture, jointly planned and implemented a pneumococcal vaccine support program with a research team at Hiroshima University in October 2010, prior to the nationwide rollout. The program, which ran until March 2015, aimed to promote community health and provided PPSV23 vaccination to all residents aged 65 and over. The vaccine used in the project was approved for the elderly in Japan at the time. As part of this collaborative initiative, a five-year follow-up survey was conducted to assess the preventive effect of the pneumonia vaccine.

In particular, we sought to understand the impact of the PPSV23 vaccine on pneumonia incidence and mortality on the elderly population in a rural setting with a high aging rate. “

Aya Sugiyama, a lecturer in the Department of Epidemiology Disease Control and Prevention at the Graduate School of Biomedical and Health Sciences, Hiroshima University

The city's residents who participated in the project ranged in age from 70 to 114 years old, with an average age of 84 years old.

To assess mortality changes after the introduction of the vaccination program, researchers used aggregated demographic data from Japanese vital statistics covering the years 2000 to 2016. They used interrupted time series analysis to quantify the level and trend changes in mortality rates over time, particularly the mortality rate before and after the In Vaccination project introduced in the city. The study aimed to generate real-world evidence of the effectiveness of vaccine support programs in super-aged societies.

Their analysis of the data showed that the pneumococcal vaccination support program for elderly residents in the city of Sera was associated with a 25 percent reduction in pneumonia mortality. “In particular, it has reversed the previously increasing trend of pneumonia mortality in the community,” Sugiyama said.

The study also provided valuable data on the true incidence of pneumonia in vaccinated older adults, with an incidence rate of 20.3 cases per 1,000 person-years. Scientists use the person-year method in studies in which they follow individuals over a period of time. A person-year is a person who is tracked for one year.

“These results highlight both the public health importance of local vaccination efforts and the burden of pneumonia in aging populations,” Sugiyama said.

The research team sees the findings as particularly relevant to Japan, which has the most aging population in the world. "With the completion of this assessment, the next step is to share these results to inform future discussions about community-based vaccination strategies. While further research is needed, we hope our results serve as a reference for regions investigating effective approaches to preventing pneumonia in older adults," Sugiyama said.

The research team includes Aya Sugiyama, Kanon Abe, Hirohito Imada, Bunlorn Sun, Golda Ataa Akuffo, Tomoyuki Akita, Shingo Fukuma, Junko Tanaka and Noboru Hattori from Hiroshima University; Masaaki Kataoka from Sera Central Public Hospital; and Kentaro Tokumo from Sera Central Public Hospital, Hiroshima University and Hiroshima University Hospital.

The research is funded by the municipality of Sera Town.

Sources: