Rotavirus-associated gastroenteritis has been a global health problem until the successful development and marketing of rotavirus vaccines, with the World Health Organisation (WHO) first recommending the inclusion of rotavirus vaccines in all national immunisation programmes ten years ago in 2009. As of October 2019, 98 countries worldwide have added rotavirus vaccines into their national immunisation programmes. In Japan, the rotavirus vaccines have been marketed since 2012, and in 2019 the vaccines were been approved to be part of the routine immunisation programme for children where the funding will change. With this recent change in policy it is important to assess the cost-effectiveness and
monitor changes in the epidemiology in Japan. Previous analyses for Japan ignored transmission dynamics, herd
immunity effects, the impact on the quality of life of parents/carers from illness and from premature deaths of children
under 5 years, and rotavirus-associated mortality. Taken together, it is likely that the impact of a publicly funded universal rotavirus vaccination programme is underestimated.

This project will comprehensively revisit the health and economic impact of universal rotavirus vaccination in Japan, with inclusion of non-linear and herd-immunity effects. The work will apply up-to-date mathematical modelling and cost-effectiveness techniques, which will also allow drawing comparisons to the UK and other
(high-income) countries worldwide.

The project is part of wider collaboration between LSHTM, Nagasaki University and the National Institute of Infectious Diseases (NIID) of Japan, and it will be informing national vaccination policy making in Japan.