1 Tokyo Foundation for Policy Research, Tokyo 106-6234, Japan. Electronic address: kashimizu-ngy@umin.ac.jp.
2 Department of Health Policy, London School of Economics and Political Science, London WC2A 2AE, UK; Institute of Global Health Innovation, Imperial College London, London SW7 2NA, UK.
3 Tokyo Foundation for Policy Research, Tokyo 106-6234, Japan; Soma COVID-19 Vaccination Medical Centre, Fukushima 976-8601, Japan.