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Volume 32, Number 11—November 2026

Synopsis

Importation-Driven Measles Resurgence and the Fragility of Elimination, Japan, 2024–2026

Koichiro YujiComments to Author , Wakako Yuji, and Eisuke Adachi
Author affiliation: The Institute of Medical Science, The University of Tokyo, Tokyo, Japan (K. Yuji, E. Adachi); Kitasato Institute Hospital, Tokyo (K. Yuji, W. Yuji, E. Adachi)

Main Article

Figure 3

Measles cases by age group reported in epidemiologic weeks 1–20 of 2019 and 2026, Japan. Age-specific incidence in weeks 1–20 of 2019 (n = 533) and 2026 (n = 498) were calculated from national case counts and population estimates for the corresponding year. Shading indicates 2 cohorts defined by vaccination policy. Yellow shading indicates the age groups of the transitional cohorts, born ≈1995–2005, who received a second dose of measles vaccine, if they did so, through the time-limited 2008–2013 campaign or the opening years of the 2-dose schedule. Light blue shading indicates the single-dose cohort, born ≈1978–1990, who were offered 1 routine dose and were not eligible for the second dose through the campaign. Black arrow indicates peak age group in 2019; red arrow indicates peak age group in 2026. Source: Japan Institute for Health Security Infectious Disease Weekly Report (12,18,36).

Figure 3. Measles cases by age group reported in epidemiologic weeks 1–20 of 2019 and 2026, Japan. Age-specific incidence in weeks 1–20 of 2019 (n = 533) and 2026 (n = 498) were calculated from national case counts and population estimates for the corresponding year. Shading indicates 2 cohorts defined by vaccination policy. Yellow shading indicates the age groups of the transitional cohorts, born ≈1995–2005, who received a second dose of measles vaccine, if they did so, through the time-limited 2008–2013 campaign or the opening years of the 2-dose schedule. Light blue shading indicates the single-dose cohort, born ≈1978–1990, who were offered 1 routine dose and were not eligible for the second dose through the campaign. Black arrow indicates peak age group in 2019; red arrow indicates peak age group in 2026. Source: Japan Institute for Health Security Infectious Disease Weekly Report (12,18,36).

Main Article

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Page created: September 24, 2026
Page updated: September 29, 2026
Page reviewed: September 29, 2026
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