There is an increased risk of severe coronavirus disease-2019 (COVID-19) during pregnancy, as well as an increased risk of adverse birth outcomes. Therefore, the aim of this study is to assess the safety, reactogenicity and immunogenicity of Ad26.COV2.S in adult participants in the second and/or third trimester of pregnancy. Ad26.COV2.S (also known as Ad26COVS1) is a monovalent vaccine composed of a recombinant, replication incompetent adenovirus type 26 (Ad26) vector, constructed to encode the S protein derived from a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) clinical isolate, stabilized in its prefusion conformation. For each adult participant, the total study duration from screening until the last follow-up visit will be approximately 16 months. The study will consist of a screening phase (28 days), vaccination period (study period from vaccination to pregnancy completion/termination) and a follow-up period (up to 12 months post pregnancy completion/termination). For neonates/infants born to the participants in the study will be followed for approximately 12 months postpartum. Safety assessments will include immunogenicity assessments, physical examination, vital signs, clinical safety laboratory assessments, medical, obstetric and delivery history, pregnancy outcome, neonate safety assessment, adverse events (AEs), serious adverse events (SAEs), and adverse events of special interest (AESI).
The purpose of this study is to assess the safety and reactogenicity of Ad26.COV2.S administered intramuscularly (IM) as a 1-dose schedule at the standard dose level in adult participants during the second and/or third trimester of pregnancy and (potentially) post-partum; to assess the humoral immune response in peripheral blood of adult participants to Ad26.COV2.S administered IM as a 1-dose schedule during the second and/or third trimester of pregnancy, 28 days after vaccination.