FAIRALL, L et al. 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, South Africa, v. 115, n. 7, p. e2532 , 2025. DOI: 10.7196/SAMJ.2025.v115i7.2532. Disponível em: https://samajournals.co.za/index.php/samj/article/view/2532. Acesso em: 7 oct. 2025.