Prospective clinical surveillance for severe acute respiratory illness and COVID-19 vaccine effectiveness in Kenyan hospitals during the COVID-19 pandemic by Lucinde, RK, Gathuri, H, Isaaka, L, Ogero, M, Mumelo, L, Kimego, D, Mbevi, G, Wanyama, C, Otieno, EO, Mwakio, S, Saisi, M, Isinde, E, Oginga, IN, Wachira, A, Manuthu, E, Kariuki, H, Nyikuli, J, Wekesa, C, Otedo, A, Bosire, H, Okoth, SB, Ongalo, W, Mukabi, D, Lusamba, W, Berkley, JA, English, M, Agweyu, A