The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods to examine these parameters were developed, validated and applied in three patients of a family which underwent an ambulatory course of COVID-19 for six months. The virus load had almost completely disappeared after about four weeks. Serum IgA levels to the S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau at approximately six weeks, and stayed elevated over the observation period. Virus-neutralizing activity reached a peak about 4 weeks after disease onset but dropped slowly. The longitudinal associations of virus neutralization and the serological immune response suggest immunity in patients even after a mild clinical course of COVID-19.
【저자키워드】 COVID-19, anti-SARS-CoV-2 antibodies, SARS-CoV-2 RT-qPCR, SARS-CoV-2 S1-RDB protein, SARS-CoV-2 N-protein, SARS-CoV-2 neutralizing activity, 【초록키워드】 SARS-CoV-2, immune response, Immunity, Neutralizing activity, Clinical course, family, IgG antibody, IgG antibodies, IgA, nasopharyngeal, Patient, Virus neutralization, Mild, serological, virus load, COVID-19 patients, Blood, association, disease onset, NAbs, IgG levels, observation period, N-protein, clinical disease, plateau, parameter, Course, peaked, elevated, applied, reached, IgA level, declined, dropped, IgG level, 【제목키워드】 SARS-CoV-2, activity, Month,