Hydroxychloroquine pre-exposure prophylaxis to prevent SARS-CoV-2 among health care workers at risk for SARS-CoV-2 exposure: A nonrandomized controlled trial (preprint)

Background: Aerosol-generating procedures increase the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among health care workers (HCWs). An effective pre-exposure prophylaxis would mitigate this risk. Objective: To determine the efficacy of pre-exposure prophylactic hydroxychloroquine for the prevention of SARS-CoV-2 infection and symptomatic coronavirus 19 disease (COVID-19) among HCWs at high occupational risk of SARS-CoV-2 exposure. Methods: 130 HCWs in the New York University Langone Health System (NYULHS) who performed aerosol-generating procedures on patients with COVID-19 or provided bedside care for inpatients with COVID-19 or persons with suspected COVID-19 in an emergency department, for at least three shifts in a 7-day period, during the first 2020 COVID-19 wave in New York City were enrolled. Participants elected to take oral hydroxychloroquine, 600 mg on day 1 followed by 200 mg daily, or not take hydroxychloroquine for up to 90 days. Participants self-collected dried blood spots and completed digital questionnaires regarding COVID-19 symptoms, adverse events, and other COVID-19 medication use. Results: Six participants (7.5%) seroconverted during the trial: four who took hydroxychloroquine (6.8%) and two who declined hydroxychloroquine (9.5%). All participants not taking hydroxychloroquine reported COVID-19 symptoms at seroconversion compared to one of four participants (25%) who took hydroxychloroquine. Adverse events occurred in eight participants (9.6%) on hydroxychloroquine and were mostly mild. Conclusions: This study (ClinicalTrials.gov NCT04354870) did not demonstrate a statistically significant difference in SARS-CoV-2 seroconversion associated with hydroxychloroquine pre-exposure prophylaxis among HCWs at high risk of occupational SARS-CoV-2 exposure, although was underpowered and a high rate of hydroxychloroquine discontinuation was observed.

Safety and immunogenicity of a SARS-CoV-2 recombinant protein vaccine with AS03 adjuvant in healthy adults: interim findings from a phase 2, randomised, dose-finding, multi-centre study (preprint)

Background This study evaluated the safety and immunogenicity of an AS03-adjuvanted SARS-CoV-2 recombinant protein candidate vaccine, CoV2 preS dTM. Methods This Phase 2, modified double-blind, parallel-group study (NCT04762680) was conducted in adults, including those at increased risk of severe COVID-19. Participants were randomised 1:1:1, stratified by age (18-59/[≥]60 years), rapid serodiagnostic test (positive/negative) and high-risk medical conditions (yes/no), to receive two injections (day [D]1 and D22) of 5{micro}g, 10{micro}g or 15{micro}g of CoV2 preS dTM antigen with fixed AS03 content. Interim safety and reactogenicity results (to D43) and neutralising antibodies (Nabs) against the D614G variant are presented (primary objectives). Findings Of 722 participants enrolled and randomised between 24 February and 8 March 2021, 721 received [≥]1 injections (5{micro}g, n=240; 10{micro}g, n=239; 15{micro}g, n=242). Four participants reported unsolicited immediate adverse events (AEs), two were vaccine-related (investigator assessment). Five participants reported seven vaccine-related medically-attended AEs. No vaccine-related serious AEs and no AEs of special interest were reported. Solicited reactions (local and systemic) were reported at similar frequencies between study groups; these were mostly mild to moderate and transient, with higher frequency and intensity post-injection 2 than post-injection 1. In SARS-CoV-2 na ive participants at D36, 96'9%, 97.0% and 97'6% of participants had [≥]4-fold-rise in NAb titres from baseline in the 5{micro}g-, 10{micro}g- and 15{micro}g-dose groups, respectively. NAb titres increased with antigen dose in younger (GMTs: 2954, 3951 and 5142 for 5{micro}g-, 10{micro}g- and 15{micro}g-dose groups) but not older adults (GMTs: 1628, 1393 and 1736, respectively). NAb titres in non-na ive adults after one injection were higher than titres after two injections in na ive adults. Interpretation Two injections of CoV2 preS dTM-AS03 demonstrated acceptable safety and reactogenicity, and robust immunogenicity in SARS-CoV-2 na ive and non-na ive adults. These results informed antigen dose selection for progression to Phase 3 evaluation of primary and booster vaccination.