Factors affecting motivation for receiving a booster dose of the COVID-19 vaccine among Japanese university students and staff: a cross-sectional questionnaire survey oleh Sho Uchida, Shunsuke Uno, Masahiro Kondo, Yoshifumi Uwamino, Ho Namkoong, Tomoyasu Nishimura, Kana Misawa, Shoko Kashimura, Kei Yamato, Tamami Ishizaka, Kengo Nagashima, Yuko Kitagawa, Naoki Hasegawa