Vaccine characteristics
STERILE
PTX-COVID19-B vaccine is an off-white, sterile, preservative-free, frozen suspension for IM injection. It was produced as a multidose vial containing 2 mL of 0.2 mg/mL and supplied as a frozen suspension. Preparation of the vaccine for 16-µg, and 40-µg, dose was done by diluting the vaccine with saline to obtain 0.5 mL injection volume. No dilution was required for the 100-µg dose. Stability of PTX-COVID19-B was performed on vials stored at − 80 °C, − 20 °C for one year and the results indicate that at both temperatures the release specification stays constant. Stability for the vaccine stored at refrigerated conditions of 2–8 °C showed no changes in any of the release parameters for up to 3 months. Further stability studies are being conducted for more advanced stages of clinical development.