Several COVID-19 vaccines have received emergency approval. Here we assess the immunogenicity of a single dose of the AZD1222 vaccine, at one month, in a cohort of health care workers (HCWs) (629 naïve and 26 previously infected). 93.4% of naïve HCWs seroconverted, irrespective of age and gender. Haemagglutination test for antibodies to the receptor binding domain (RBD), surrogate neutralization assay (sVNT) and ex vivo IFNγ ELISpot assays were carried out in a sub-cohort. ACE2 blocking antibodies (measured by sVNT) were detected in 67/69 (97.1%) of naïve HCWs. Antibody levels to the RBD of the wild-type virus were higher than to RBD of B.1.1.7, and titres to B.1.351 were very low. Ex vivo T cell responses were observed in 30.8% to 61.7% in naïve HCWs. Previously infected HCWs, developed significantly higher (p < 0.0001) ACE2 blocking antibodies and antibodies to the RBD for the variants B.1.1.7 and B.1.351. This study shows high seroconversion after one vaccine dose, but also suggests that one vaccine dose may be insufficient to protect against emerging variants. Here the authors show in a large cohort of healthcare workers that one dose of the AZD1222 vaccine seroconverts 92.9% of vaccinees, irrespective of age and gender, and results in high antibody titers to wild-type SARS-CoV-2 but only low titers to the B.1.351 variant.
【저자키워드】 SARS-CoV-2, Adaptive immunity, Vaccines, Health occupations, 【초록키워드】 ACE2, Vaccine, COVID-19 vaccine, immunogenicity, Health care, Healthcare workers, antibody, B.1.351, health care workers, variant, variants, healthcare worker, Receptor binding domain, vaccine dose, Cohort, T cell, AZD1222, Seroconversion, Neutralization assay, B.1.1.7, HCWs, RBD, Antibody titer, Health care worker, large cohort, antibody levels, ELISpot assay, T cell response, Antibody titers, single dose, antibody level, dose, HCW, Ex vivo, blocking antibodies, titres, B.1.351 variant, sVNT, IFNγ, naïve, approval, titre, wild-type SARS-CoV-2, wild-type virus, vaccinees, seroconvert, ELISpot assays, PROTECT, carried, seroconverted, the RBD, significantly higher, age and gender, sub-cohort, 【제목키워드】 Vaccine, response, Health care worker,