SARS-CoV-2 Immune Responses After COVID-19 Therapy and Subsequent Vaccine

A5404 is a phase IV, open-label study. The objective of A5404 is to evaluate how prior investigational therapy for COVID-19 versus comparator (placebo or active comparator) affects vaccine response. The safety of mRNA COVID-19 vaccines is also explored. Eligible A5404 participants include: Participants of ACTIV-2/A5401 at selected sites who received an investigational therapy or its comparator; and persons without known history of prior SARS-CoV-2 infection defined as no known history of any SARS-CoV-2 positive test (non-A5401 participants). In line with our protocol, for outcome measures related to neutralizing antibodies and adverse events, we further break down the ACTIV-2/A5401 participants into two exposure groups: those who received an active therapy (AZD7442 IM or IV, BRII-196 + BRII 198 IV, SAB 185 (3,840 or 10,240 units/kg) IV, BMS 096414+BMS 986413 subcutaneous) and those who received Camostat Oral or Placebo. Participants of ACTIV-2/A5401 received study-provided standard dosing of the Moderna mRNA-1273 vaccine, or a community-provided mRNA-based COVID-19 vaccine (e.g., Moderna or Pfizer). Participants in ACTIV-2/A5401 received their mRNA-based COVID-19 vaccine 60-240 days after receiving their last dose of a select ACTIV-2/A5401 investigational therapy, or its comparator. Participants without prior COVID-19 received study-provided standard dosing of the Moderna mRNA-1273 vaccine. The study closed early to accrual on February 25, 2022 due to slow enrollment. Clarification Memo #1 (dated January 11, 2023) reflects decisions to discontinue follow up at study Day 365 instead of following participants to Day 730 after the first dose of vaccine and to reallocate some secondary outcome measures to exploratory outcome measures.