Population Immunity and Covid-19 Severity with Omicron Variant in South Africa.

BACKGROUND: The B.1.1.529 (omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified on November 25, 2021, in Gauteng province, South Africa. Data regarding the seroprevalence of SARS-CoV-2 IgG in Gauteng before the fourth wave of coronavirus disease 2019 (Covid-19), in which the omicron variant was dominant, are needed. METHODS: We conducted a seroepidemiologic survey from October 22 to December 9, 2021, in Gauteng to determine the seroprevalence of SARS-CoV-2 IgG. Households included in a previous seroepidemiologic survey (conducted from November 2020 to January 2021) were contacted; to account for changes in the survey population, there was a 10% increase in the households contacted, with the use of the same sampling framework. Dried-blood-spot samples were tested for IgG against SARS-CoV-2 spike protein and nucleocapsid protein with the use of quantitative assays. We also evaluated Covid-19 epidemiologic trends in Gauteng, including cases, hospitalizations, recorded deaths, and excess deaths from the start of the pandemic through January 12, 2022. RESULTS: Samples were obtained from 7010 participants, of whom 1319 (18.8%) had received a Covid-19 vaccine. The seroprevalence of SARS-CoV-2 IgG ranged from 56.2% (95% confidence interval [CI], 52.6 to 59.7) among children younger than 12 years of age to 79.7% (95% CI, 77.6 to 81.5) among adults older than 50 years of age. Vaccinated participants were more likely to be seropositive for SARS-CoV-2 than unvaccinated participants (93.1% vs. 68.4%). Epidemiologic data showed that the incidence of SARS-CoV-2 infection increased and subsequently declined more rapidly during the fourth wave than it had during the three previous waves. The incidence of infection was decoupled from the incidences of hospitalization, recorded death, and excess death during the fourth wave, as compared with the proportions seen during previous waves. CONCLUSIONS: Widespread underlying SARS-CoV-2 seropositivity was observed in Gauteng before the omicron-dominant wave of Covid-19. Epidemiologic data showed a decoupling of hospitalizations and deaths from infections while omicron was circulating. (Funded by the Bill and Melinda Gates Foundation.).

Out-of-Facility Multimonth Dispensing of Antiretroviral Treatment: A Pooled Analysis Using Individual Patient Data From Cluster-Randomized Trials in Southern Africa.

BACKGROUND: Out-of-facility multi-month dispensing (MMD) is a differentiated service delivery model which provides antiretroviral treatment (ART) at intervals of up to 6 monthly in the community. Limited randomized evidence investigating out-of-facility MMD is available. We evaluated participant outcomes and compared out-of-facility MMD models using data from cluster-randomized trials in Southern Africa. SETTING: Eight districts in Zimbabwe and Lesotho. METHODS: Individual-level participant data from 2 cluster-randomized trials that included stable adults receiving ART at 60 facilities were pooled. Both trials had 3 arms: ART collected 3-monthly at healthcare facilities (3MF, control); ART provided three-monthly in community ART groups (CAGs) (3MC); and ART provided 6-monthly in either CAGs or on an individual provider-patient basis (6MC). Participant retention, viral suppression and incidence of unscheduled facility visits were compared. RESULTS: Ten thousand one hundred thirty-six participants were included, 3817 (37.7%), 2893 (28.5%) and 3426 (33.8%) in arms 3MF, 3MC and 6MC, respectively. After 12 months, retention was non-inferior for 3MC (95.7%) vs. 3MF (95.0%) {adjusted risk difference (aRD) = 0.3 [95% confidence interval (CI): -0.8 to 1.4]}; and 6MC (95.1%) vs. 3MF [aRD = -0.2 (95% CI: -1.4 to 1.0)]. Retention was greater amongst intervention arm participants in CAGs versus 6MC participants not in CAGs, aRD = 1.5% (95% CI: 0.2% to 2.9%). Viral suppression was excellent (≥98%) and unscheduled facility visits were not increased in the intervention arms. CONCLUSIONS: Three and 6-monthly out-of-facility MMD was non-inferior versus facility-based care for stable ART patients. Out-of-facility 6-monthly MMD should incorporate small group peer support whenever possible. CLINICALTRIAL REGISTRATION: ClinicalTrials.gov NCT03238846 and NCT03438370.

Community-based differentiated service delivery models incorporating multi-month dispensing of antiretroviral treatment for newly stable people living with HIV receiving single annual clinical visits: a pooled analysis of two cluster-randomized trials in southern Africa.

INTRODUCTION: Differentiated service delivery (DSD) models for HIV treatment decrease health facility visit frequency and limit healthcare facility-based exposure to severe acute respiratory syndrome coronavirus 2. However, two important evidence gaps include understanding DSD effectiveness amongst clients commencing DSD within 12 months of antiretroviral treatment (ART) initiation and amongst clients receiving only single annual clinical consultations. To investigate these, we pooled data from two cluster-randomized trials investigating community-based DSD in Zimbabwe and Lesotho. METHODS: Individual-level participant data of newly stable adults enrolled between 6 and 12 months after ART initiation were pooled. Both trials (conducted between August 2017 and July 2019) had three arms: Standard-of-care three-monthly ART provision at healthcare facilities (SoC, control); ART provided three-monthly in community ART groups (CAGs) (3MC) and ART provided six-monthly in either CAGs or at community-distribution points (6MC). Clinical visits were three-monthly in SoC and annually in intervention arms. The primary outcome was retention in care and secondary outcomes were viral suppression (VS) and number of unscheduled facility visits 12 months after enrolment. Individual-level regression analyses were conducted by intention-to-treat specifying for clustering and adjusted for country. RESULTS AND DISCUSSION: A total of 599 participants were included; 212 (35.4%), 128 (21.4%) and 259 (43.2%) in SoC, 3MC and 6MC, respectively. Few participants aged <25 years were included (n = 32). After 12 months, 198 (93.4%), 123 (96.1%) and 248 (95.8%) were retained in SoC, 3MC and 6MC, respectively. Retention in 3MC was superior versus SoC, adjusted risk difference (aRD) = 4.6% (95% CI: 0.7%-8.5%). Retention in 6MC was non-inferior versus SoC, aRD = 1.7% (95% CI: -2.5%-5.9%) (prespecified non-inferiority aRD margin -3.25%). VS was similar between arms, 99.3, 98.6 and 98.1% in SoC, 3MC and 6MC, respectively. Adjusted risk ratio's for VS were 0.98 (95% CI: 0.92-1.03) for 3MC versus SoC, and 0.98 (CI: 0.95-1.00) for 6MC versus SoC. Unscheduled clinic visits were not increased in intervention arms: incidence rate ratio = 0.53 (CI: 0.16-1.80) for 3MC versus SoC; and 0.82 (CI: 0.25-2.79) for 6MC versus SoC. CONCLUSIONS: Community-based DSD incorporating three- and six-monthly ART refills and single annual clinical visits were at least non-inferior to standard facility-based care amongst newly stable ART clients aged ≥25 years. ClinicalTrials.gov: NCT03238846 & NCT03438370.