Vaccine
The vaccine consists of DCs and lymphocytes obtained from the blood of the peripheral autologous. First, 40 cc of blood was taken and then incubated with GM-CSF and IL-4 for 5 days to differentiate monocytes into DCs. Then, DCs and lymphocytes were incubated with recombinant SARS-CoV-2 S protein for 2 days. S protein is manufactured by LakePharma Biological (San Carlos, USA). The antigen is SARS-CoV-2 spike (S) protein pre-fusion stabilized ectodomain, C-terminus His tag, with the furin cleavage site removed and trimerization stabilized. The sequence is based on SARS-CoV-2 wild type. The amount of S protein given differs according to the dose group, namely, 0.1, 0.33, and 1.0 mcg. The vaccine composition consists of 10% DCs and 90% lymphocytes. In phase I clinical trials, a DC vaccine was given an additional GM-CSF of 250 or 500 mcg, while in phase II clinical trials, it was not given additionally. The formed DC vaccine is dissolved in the subject’s plasma before injection. Vaccines are produced following the requirements of a Good Manufacturing Product.