How to model the impact of vaccines for policymaking when the characteristics are uncertain: a case study in Thailand prior to the vaccine rollout during the COVID-19 pandemic by Luangasanatip, N, Painter, C, Pan-Ngum, W, Saralamba, S, Wichaita, T, White, L, Aguas, R, Clapham, H, Wang, Y, Isaranuwatchai, W, Teerawattananon, Y