Lancet: Ad5 vector COVID-19 vaccine Phase II clinical success.

!---- researchers recently published the results of the Iegenic and Safe Phase II clinical study of the non-replicated type 5 adenovirus (Ad5) vector COVID-19 vaccineThis random, double-blind, placebo-controlled Ad5 vector COVID-19 vaccine Phase II trial was conducted in Wuhan, China, with healthy adults over 18 years of age participating in HIV-negative participants who were previously free of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, randomly received a vaccine or placebo for 1 x 1011 virus particles per milliliter, 5 x 1010 viral particlesThe main endpoint of immunogenicity is the geometric mean titer (GMT) and 28-day neutralizing antibody response of the receptor binding domain (RBD)-specific ELISA antibody responseThe main endpoint of safety evaluation was the incidence of adverse reactions within 14 days508 participants, 50% of men, with an average age of 39.7 years, were randomly vaccinated (1 x 1011 virus particle group n x 253; 5 x 1010 virus particle group n x 129) or placebo (n-126)In the 1 x 1011 and 5 x 1010 viral particle dose groups, RBD-specific ELISA antibodies peaked at 656.5 and 571.0 on the 28th day, respectively, with serum conversion rates of 96% and 97%, respectivelyBoth doses of the vaccine produced significant neutralizing antibody responses, with participants vaccinated at 1 x 1011 and 5 x 1010 virus particles at GMT of 19.5 and 18.3, respectivelyOf the 253 participants in the 1 x 1011 viral particle group, 227 were in the 5 x 1010 virus particle dose group, and 113 were observed with specific interferon-pyrasse-linked immune responses after vaccinationOf the 253 participants in the 1 x 1011 viral particle dose group, 183 (72%) and 96 (74%) of the 129 participants in the 5 x 1010 particulate dose group reported adverse reactionsSevere adverse reactions were reported by 24 (9%) participants and 1 (1%) participants in the 1 x 1011 viral particle dose group and the 5 x 1010 particle dose group, respectivelyThe study concluded that the Ad5 vector COVID-19 vaccine was safe, and that most subjects had a significant immune response after a single immunization