ABSTRACT The recent emergence of COVID-19 variants has necessitated the development of new vaccines that stimulate the formation of high levels of neutralizing antibodies against S antigen variants. A new strategy involves the intradermal administration of heterologous vaccines composed of one or two doses of inactivated vaccine and a booster dose with the mutated S1 protein (K-S). Such vaccines improve the immune efficacy by increasing the neutralizing antibody titers and promoting specific T cell responses against five variants of the RBD protein. A viral challenge test with the B.1.617.2 (Delta) variant confirmed that both administration schedules (i.e. “1 + 1” and “2 + 1”) ensured protection against this strain. These results suggest that the aforementioned strategy is effective for protecting against new variants and enhances the anamnestic immune response in the immunized population.
【저자키워드】 SARS-CoV-2, Vaccine, variants, intradermal administration, 【초록키워드】 COVID-19, neutralizing antibody, Efficacy, immune response, Neutralizing antibodies, variant, Delta, B.1.617.2, immune, T cell, Viral, Inactivated vaccine, booster dose, T cell response, S antigen, Antibody titers, RBD protein, Neutralizing antibody titer, administration, dose, heterologous vaccine, Challenge test, viral challenge, neutralizing antibody titers, S1 protein, FIVE, effective, immunized, ENhance, IMPROVE, composed, mutated, stimulate, the RBD protein, 【제목키워드】 SARS-CoV-2 variant, heterologous vaccine, immunological, Preclinical,