Italy's ReiThera vaccine against COVID-19 showed an antibody response against the Spike protein in over 93% of volunteers three weeks after the first dose, reaching 99% after the second shot, the biotech company based in Castel Romano, near Rome, said on Monday.

Five weeks after the first vaccination the level of antibodies that connect the Spike protein and neutralize the virus was comparable to that measured in a group of patients recovering from the Covid infection who were used as a control group, the company explained.