As the first dose of Gam-COVID-Vac, is currently used as a single dose vaccine in some countries, we investigated the immunogenicity of this at 4 weeks (327 naïve individuals). 88.7% seroconverted, with significantly lower seroconversion rates in those over 60 years (p = 0.004) and significantly lower than previously seen with AZD1222 (p = 0.018). 82.6% developed ACE2 receptor blocking antibodies, although levels were significantly lower than following natural infection (p = 0.0009) and a single dose of AZD1222 (p < 0.0001). Similar titres of antibodies were observed to the receptor binding domain of WT, B.1.1.7 and B.1.617.2 compared to AZD1222, while the levels for B.1.351 were significantly higher (p = 0.006) for Gam-COVID-Vac. 30% developed ex vivo IFNγ ELISpot responses (significantly lower than AZD1222), and high frequency of CD107a expressing T cells along with memory B cell responses. Although single dose of Gam-COVID-Vac was highly immunogenic, administration of a second dose is likely to be beneficial.
【저자키워드】 immunology, Adaptive immunity, Infectious diseases, Microbiology, Molecular medicine, Lymphocytes, Vaccines, Infection, Antimicrobial responses, 【초록키워드】 antibodies, Vaccine, immunogenicity, antibody, B.1.351, T cells, B.1.617.2, ACE2 receptor, Receptor binding domain, T cell, AZD1222, B.1.1.7, response, ELISPOT, natural infection, memory B cell, single dose, administration, Frequency, in some, Ex vivo, second dose, first dose, naïve individuals, IFNγ, titre, immunogenic, seroconversion rate, Gam-COVID-Vac, CD107a, ELISpot responses, significantly lower, responses, Cell, memory B, investigated, seroconverted, significantly higher, expressing, 【제목키워드】 response,