Trial design and participants
allergy, SARS-CoV-2 infection
DISEASE, ALLERGY, SARS-COV-2 INFECTION
An investigator-initiated, participant and observer-blinded, randomized controlled trial was performed to compare the serological response following the homologous prime-boost vaccination using RBD-TT conjugated (PastoCovac, Pasteur Institute, Tehran, Iran) compared with the heterologous prime-boost using an inactivated platform (Vero Cell, Beijing Institute of Biological Products, China) in auto-HSCT recipients more than 18 years old who had received two primary doses of RBD-TT conjugated vaccine, independent of the pre-booster immunogenicity. Prior treatment with rituximab within six months, relapse of the underlying disease, previous allergy to the vaccine’s components, and history of SARS-CoV-2 infection following HSCT were the major exclusion criteria. The patients were recruited to study from Jul 22, 2022, to Jan 2, 2023, at the Hematology-Oncology-Stem Cell Transplantation Research Center (HORCSCT) of Tehran University, Tehran, Iran.