Estimation of preventable pneumococcal disease burden by PCV20 or PCV21 under the national immunization program for adults aged 65 years in Japan
- 1Toyama Institute of Health
Abstract
AimsTo estimate the preventable pneumococcal disease burden by 21-valent pneumococcal conjugate vaccine (PCV21) compared to PCV20 for the national immunization program for adults aged 65 years or older in Japan.
MethodsSerotype distribution among isolates and the annual incidence of invasive pneumococcal disease (IPD) in adults were monitored. The numbers of IPD or pneumococcal community-acquired pneumonia (pCAP) cases preventable by immunization with PCV20 or PCV21 were estimated according to reported vaccine efficacy and duration of protection in older adults. Data from our nationwide study of adult IPD surveillance and a multicenter study of pCAP were used.
ResultsThe mean annual incidence of adult patients with IPD caused by all serotypes among adults aged [≥]65 years, which declined during the COVID-19 pandemic period, recovered to 89% of the pre-pandemic level in 2025. During 2023-2025, the proportion of PCV20-non-PCV21 serotypes was 8.5% for adults aged [≥]65 years. At the current vaccination coverage rate of 40%, the numbers of preventable IPD cases (per person per year) by PCV20 and PCV21 were 36 and 53, respectively. The preventable numbers of pCAP cases by PCV20 and PCV21 were 2,821 and 4,765, respectively. The estimated number of preventable pCAP cases was approximately 80-90 times higher than that of preventable IPD cases.
ConclusionOur data indicate that PCV21 could prevent 1.5-1.7 times as many pneumococcal disease cases as PCV20 among adults aged [≥]65 years in Japan. However, PCV20 should be considered if the incidence of adult IPD cases caused by PCV20-non-PCV21 serotypes increases.
Related
- National trends of unique-PCV20 / PCV21 serotypes, common PCV20-PCV21 and non-vaccine serotypes causing invasive pneumococcal disease in adults in Spain during the period 2009-2026
- Evaluating a multi-vaccine respiratory immunization strategy involving SARS-CoV-2, pneumococcal, and influenza vaccines in adults: A randomized, open-label, multicenter, controlled, non-inferiority Phase IV trial in China.
- Timeliness of childhood vaccination in Iran: Survival analysis of a national immunization survey, 2019.
- National Immunization Technical Advisory Groups maturity and RSV vaccination policies in Europe
- Severe Invasive Pneumococcal Disease in Two Siblings: Austrian Syndrome and Infected Aortic Aneurysm
BibTeX
@misc{tamura2026estimation,
title = {{Estimation of preventable pneumococcal disease burden by PCV20 or PCV21 under the national immunization program for adults aged 65 years in Japan}},
author = {K. Tamura and B. Chang and R. Shimbashi and K. Gotoh and Y. Tanabe and K. Kuronuma and K. Ohshima and T. Maruyama and M. Nakamatsu and S. Abe and K. Kasahara and T. Ooka and Y. Arakawa and Y. Kinjo and Y. Akeda and K. Oishi},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.15.26363097},
url = {https://www.medrxiv.org/content/10.64898/2026.09.15.26363097v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Estimation of preventable pneumococcal disease burden by PCV20 or PCV21 under the national immunization program for adults aged 65 years in Japan
AU - K. Tamura
AU - B. Chang
AU - R. Shimbashi
AU - K. Gotoh
AU - Y. Tanabe
AU - K. Kuronuma
AU - K. Ohshima
AU - T. Maruyama
AU - M. Nakamatsu
AU - S. Abe
AU - K. Kasahara
AU - T. Ooka
AU - Y. Arakawa
AU - Y. Kinjo
AU - Y. Akeda
AU - K. Oishi
PY - 2026
DA - 2026/09/15
PB - medRxiv
DO - 10.64898/2026.09.15.26363097
UR - https://www.medrxiv.org/content/10.64898/2026.09.15.26363097v1
AB - AimsTo estimate the preventable pneumococcal disease burden by 21-valent pneumococcal conjugate vaccine (PCV21) compared to PCV20 for the national immunization program for adults aged 65 years or older in Japan. MethodsSerotype distribution among isolates and the annual incidence of invasive pneumococcal disease (IPD) in adults were monitored. The numbers of IPD or pneumococcal community-acquired pneumonia (pCAP) cases preventable by immunization with PCV20 or PCV21 were estimated according to reported vaccine efficacy and duration of protection in older adults. Data from our nationwide study of adult IPD surveillance and a multicenter study of pCAP were used. ResultsThe mean annual incidence of adult patients with IPD caused by all serotypes among adults aged [≥]65 years, which declined during the COVID-19 pandemic period, recovered to 89% of the pre-pandemic level in 2025. During 2023-2025, the proportion of PCV20-non-PCV21 serotypes was 8.5% for adults aged [≥]65 years. At the current vaccination coverage rate of 40%, the numbers of preventable IPD cases (per person per year) by PCV20 and PCV21 were 36 and 53, respectively. The preventable numbers of pCAP cases by PCV20 and PCV21 were 2,821 and 4,765, respectively. The estimated number of preventable pCAP cases was approximately 80-90 times higher than that of preventable IPD cases. ConclusionOur data indicate that PCV21 could prevent 1.5-1.7 times as many pneumococcal disease cases as PCV20 among adults aged [≥]65 years in Japan. However, PCV20 should be considered if the incidence of adult IPD cases caused by PCV20-non-PCV21 serotypes increases.
ER -