Objective: There is scarce evidence regarding the long-term persistence of neutralizing antibodies among coronavirus disease 2019 (COVID-19) survivors. This study determined neutralizing antibody titers (NT 50 ) and antibodies against spike protein (SP) or nucleocapsid protein (NP) antigens approximately 6 months after the diagnosis of COVID-19. Methods: COVID-19 survivors in Japan were recruited. Serum samples and data related to patients’ characteristics and COVID-19 history were collected. NT 50 and titers of antibodies against NP and SP antigens were measured at 20–32 weeks after the first positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test results. Factors associated with NT 50 were identified using the multivariable linear regression and the correlations among NT 50 and titers of immunoglobulin G (IgG) and total immunoglobulins (Igs) against NP and SP were assessed by Spearman’s correlation. Results: Among 376 participants (median [range] days after testing positive for SARS-CoV-2, 180 (147–224); median [range] years of age, 50 (20–78); 188 [50%] male), most tested positive for NT 50 ( n = 367, 98%), SP-IgG ( n = 344, 91%), SP-total Ig ( n = 369, 98%), NP-IgG ( n = 314, 84%), and NP-total Ig ( n = 365, 97%). Regression analysis indicated that higher BMI, fever, and the requirement of mechanical ventilation or extracorporeal membrane oxygenation were significantly associated with higher NT 50 . Anti-SP antibodies correlated moderately with NT 50 (Spearman’s correlation: 0.63 for SP IgG; 0.57 for SP-total Ig), while the correlation was weak for anti-NP antibodies (0.37 for NP IgG; 0.32 for NP-total Ig). Conclusions: Most COVID-19 survivors had sustained neutralizing antibodies and tested positive for SP-total Ig and NP-total Ig approximately 6 months after infection.
【저자키워드】 COVID-19, neutralizing antibody, SARS-CoV-2, Immunity, quantitative serological test, 【초록키워드】 coronavirus disease, IgG, coronavirus, mechanical ventilation, antibody, Infection, Spike protein, nucleocapsid protein, Antigen, extracorporeal membrane oxygenation, Characteristics, Survivors, Immunoglobulin, persistence, Fever, male, Japan, Linear regression, age, BMI, correlation, Neutralizing antibody titer, Evidence, Analysis, Regression, acute respiratory syndrome, Factor, participant, positive, serum sample, MOST, survivor, Spearman’s correlation, first positive, multivariable, tested, collected, significantly, recruited, indicated, median, correlated, sustained, were measured, diagnosis of COVID-19, were assessed, 【제목키워드】 Japanese, Month,