Giuseppe
Emeritus
[Source: PLoS ONE, full text: (LINK). Abstract, edited.]
Influenza-Related Mortality Trends in Japanese and American Seniors: Evidence for the Indirect Mortality Benefits of Vaccinating Schoolchildren
by Vivek Charu, C?cile Viboud, Lone Simonsen, Katharine Sturm-Ramirez, Masayoshi Shinjoh, Gerardo Chowell, Mark Miller, Norio Sugaya
Background
The historical Japanese influenza vaccination program targeted at schoolchildren provides a unique opportunity to evaluate the indirect benefits of vaccinating high-transmitter groups to mitigate disease burden among seniors. Here we characterize the indirect mortality benefits of vaccinating schoolchildren based on data from Japan and the US.
Methods
We compared age-specific influenza-related excess mortality rates in Japanese seniors aged ≥65 years during the schoolchildren vaccination program (1978?1994) and after the program was discontinued (1995?2006). Indirect vaccine benefits were adjusted for demographic changes, socioeconomics and dominant influenza subtype; US mortality data were used as a control.
Results
We estimate that the schoolchildren vaccination program conferred a 36% adjusted mortality reduction among Japanese seniors (95%CI: 17?51%), corresponding to ∼1,000 senior deaths averted by vaccination annually (95%CI: 400?1,800). In contrast, influenza-related mortality did not change among US seniors, despite increasing vaccine coverage in this population.
Conclusions
The Japanese schoolchildren vaccination program was associated with substantial indirect mortality benefits in seniors.
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Background
The historical Japanese influenza vaccination program targeted at schoolchildren provides a unique opportunity to evaluate the indirect benefits of vaccinating high-transmitter groups to mitigate disease burden among seniors. Here we characterize the indirect mortality benefits of vaccinating schoolchildren based on data from Japan and the US.
Methods
We compared age-specific influenza-related excess mortality rates in Japanese seniors aged ≥65 years during the schoolchildren vaccination program (1978?1994) and after the program was discontinued (1995?2006). Indirect vaccine benefits were adjusted for demographic changes, socioeconomics and dominant influenza subtype; US mortality data were used as a control.
Results
We estimate that the schoolchildren vaccination program conferred a 36% adjusted mortality reduction among Japanese seniors (95%CI: 17?51%), corresponding to ∼1,000 senior deaths averted by vaccination annually (95%CI: 400?1,800). In contrast, influenza-related mortality did not change among US seniors, despite increasing vaccine coverage in this population.
Conclusions
The Japanese schoolchildren vaccination program was associated with substantial indirect mortality benefits in seniors.