Fairall, L., Yende-Zuma, N., Reddy, T. ., Garrett, N., Goga, A., Bennet, S., Folb, N., Seocharan, I., Mametja, S., Semenya, M., Simelane, S. R. N., L-G, & Gray, G. E. (2025). Real-world effectiveness of Ad26.COV2.S or BNT162b2 booster vaccines against severe COVID-19 in adults who received a primary dose of Ad26.COV2.S in South Africa during the Delta period: A retrospective cohort study using medical scheme data. South African Medical Journal, 115(7), e2532 . https://doi.org/10.7196/SAMJ.2025.v115i7.2532