Community stakeholder engagement during a vaccine demonstration project in Nigeria: lessons on implementation of the good participatory practice guidelines oleh Morenike Oluwatoyin Folayan, Florita Durueke, Wika Gofwen, Godwin Godo-Odemijie, Chuks Okonkwo, Bali Nanmak, Sophia Osawe, Evaezi Okporoko, Alash’le Abimiku