Effectiveness and Durability of the BNT162b2 Vaccine against Omicron Sublineages in South AfricaTo the Editor: Data are limited regarding the effectiveness of the BNT162b2 vaccine (Pfizer-BioNTech) against the BA.4 and BA.5 sublineages of the B.1.1.529(omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that drove the recent fifth wave of infection in South Africa. 1 We previously reported a vaccine effectiveness of 70% after two doses of the BNT162b2 vaccine against severe disease during the fourth wave of omicron infection driven by the BA.1 sublineage in South Africa. 1,2 In this analysis, we separately assessed the effectiveness and durability of the BNT162b2 vaccine against BA.1 or BA.2 and against BA.4 or BA.5 among members of Discovery Health, a medical care organization that provides health insurance to 3.7 million persons in South Africa.During the period from November 15, 2021, to June 24, 2022, a total of 32,883 patients who had been hospitalized for medical treatment underwent polymerase-chain-reaction testing for SARS-CoV-2, a period that spanned the BA.1-BA.2 and BA.4-BA.5 omicron waves.Of these patients, * In South Africa, the BA.1 and BA.2 sublineages of the omicron variant were dominant from November 15, 2021, to February 28, 2022; the BA.4 and BA.5 sublineages were dominant from April 15 to June 24, 2022.Estimates of vaccine effectiveness (VE) are provided only if the P value was less than 0.05 for the between-group difference in the calculation of the odds ratio from the test-negative case-control design, if the number of polymerase-chain-reaction assays on admission was available, and if more than 10 admissions were observed for the estimate.Estimates of vaccine effectiveness have not been adjusted for multiplicity.CI denotes confidence interval.