Alotaibi, A., Almudarra, S.S., Algarni, H.S. , Bakhsh, Y., Dafaalla, Z.M.E., Alhowail, N.A. and Assiri, A.M. 2021. Adherence to Vaccine Requirements among Hajj Pilgrims in Saudi Arabia, 2017-2019. Tropical Health and Medical Research. 3, 2 (Aug. 2021), 86–97. DOI:https://doi.org/10.35916/thmr.v3i2.54.