Introduction
CORONAVIRUS, MAY, SEVERE ACUTE RESPIRATORY SYNDROME
The coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) worldwide pandemic that started in 2019 continues to affect multiple countries around the world where access to vaccines is limitedTo provide an alternative prophylactic vaccine against SARS-CoV-2, Providence Therapeutics Holdings, Inc. (PT) developed an mRNA vaccine, PTX-COVID19-B, composed of a lipid nanoparticle containing modified mRNA that encodes for full-length Spike (S) protein with glycine in position 614 (G614). By March of 2020, the D614G variant of SARS-CoV-2 was the predominant strain worldwide and this substitution has prevailed in current, more transmissible variants of concern (VOCs)Reported here are findings of the Phase 1 study to evaluate the safety, tolerability, and immunogenicity of PTX-COVID19-B vaccine in healthy seronegative adults aged 18–64. Our previous mouse studies indicated that immunizations with 10–20 μg of PTX-COVID19-B did not show any safety signal and could induce strong immune responses, therefore 16 μg was selected as the starting low dose for the Phase 1 trial. Mid and high doses were selected by increasing two and a half times the previous dose resulting in 40 μg and 100 μg respectively. The study began in January 2021 and enrollment was completed in April 2021. The safety database was locked, and analysis was performed on data up to day 42 after the first dose in May 2021. Immunological data is reported up to week 26 (day 180).