Abstract
Benchmarks for protective immunity from infection or severe disease after SARS-CoV-2 vaccination are still being defined. Here, we characterized virus neutralizing and ELISA antibody levels, cellular immune responses, and viral variants in 4 separate groups: healthy controls (HCs) weeks (early) or months (late) following vaccination in comparison with symptomatic patients with SARS-CoV-2 after partial or full mRNA vaccination. During the period of the study, most symptomatic breakthrough infections were caused by the SARS-CoV-2 Alpha variant. Neutralizing antibody levels in the HCs were sustained over time against the vaccine parent virus but decreased against the Alpha variant, whereas IgG titers and T cell responses against the parent virus and Alpha variant declined over time. Both partially and fully vaccinated patients with symptomatic infections had lower virus neutralizing antibody levels against the parent virus than the HCs, similar IgG antibody titers, and similar virus-specific T cell responses measured by IFN-γ. Compared with HCs, neutralization activity against the Alpha variant was lower in the partially vaccinated infected patients and tended to be lower in the fully vaccinated infected patients. In this cohort of breakthrough infections, parent virus neutralization was the superior predictor of breakthrough infections with the Alpha variant of SARS-CoV-2.
Keywords: Adaptive immunity; COVID-19; Cellular immune response; Genetic variation; Infectious disease.
【저자키워드】 COVID-19, Adaptive immunity, Cellular immune response, Infectious disease, Genetic variation, 【초록키워드】 neutralizing antibody, SARS-CoV-2, Adaptive immunity, mRNA vaccination, vaccination, antibody, Cellular immune response, Infection, Infectious disease, virus, ELISA, immune, Cohort, T cell, IgG antibody, Viral, Symptomatic patients, protective immunity, symptomatic, immune responses, response, Genetic variation, T cell responses, Patient, Virus neutralization, Viral variants, Alpha, breakthrough infections, Neutralizing, antibody levels, Breakthrough infection, Alpha variant, viral variant, disease, T cell response, Antibody titers, SARS-CoV-2 vaccination, IFN-γ, symptomatic infection, IgG titer, severe disease, infected patients, healthy control, neutralization activity, IgG antibody titers, cellular immune responses, IgG titers, symptomatic infections, defined, caused, characterized, infected patient, the vaccine, sustained, virus-specific T cell, declined, HCs, symptomatic patient, the SARS-CoV-2, 【제목키워드】 SARS-CoV-2, immune response, Infection, symptomatic, Patient,