Neutralizing Antibody Response and Associated Factors in Coronavirus-19 Disease (COVID-19) up to One Month: A Case-Series of 129 Hospitalized Patients

Abstract

Purpose Little is known about the characteristics of neutralizing antibody(NAb) response in patients recovered COVID - 19. We aimed to elucidate the factors affecting presence and titers of in an early phase of infection up to 30 days.Methods A total of 129 laboratory-confirmed COVID-19 patients in a tertiary-care hospital were enrolled. Clinical and laboratory data were obtained retrospectively. SARS-CoV-2 specific NAb, IgM, and IgG antibody responses were analyzed. NAb-positive and negative patients were compared, to examine potential associations between clinical, demographical, and laboratory characteristics and the presence/titers of NAb.Results SARS-CoV-2 specific NAb, IgM and IgG were detected at the time of hospital discharge in 60.5%, 30.2%, and 51.9% of the patients, respectively. The presence of antibodies was 42.4%(NAb), 20.3%(IgM) and 44.1%(IgG) among patients within 5-9 days since onset; increased to 79.5%(NAb), 34.1%(IgM) and 47.7%(IgG) by 10-14 days; and detected in 66.7%(NAb), 50%(IgM), 83.3%(IgG) at/after day-15, following symptom onset. The median titer of neutralizing antibody(SN 50) was significantly higher in severe patients(25 versus 7.5, p= 0.009). Of the 23 severe patients, 52.2%(n=12) had higher NAb titers (i.e., SN 50 ≥ 1:25) when compared to that in non-severe patients(p= 0.021; OR = 2.89; 95%CI= 1.15 – 7.28), yet, potential effect of follow-up time on NAb status and titers could not be ruled out.Conclusion Presence and higher titers of NAb were detected more in severe patients compared to their non-severe counterparts. Survival analysis suggested that this difference could at least be partially explained by the length of follow-up after symptoms’ onset.

The changing dynamics of neutralizing antibody response within 10 months of SARS‐CoV‐2 infections

“…[13][14][15] In terms of SARS-CoV-2 infection, there are several studies conducted in acute and early convalescence periods and they have reported that NAb titers vary depending on the severity of the primary infection and the length of time from onset. 2,5,12 In addition, Legros et al 16 In the present study, the presence and titers of long-term NAb response elicited by the primary infection were investigated. Baseline and the follow-up serum samples were investigated to clarify the persistence of NAbs and to determine the change of NAb levels compared to baseline over time up to 10 months after primary infection.…”

“…Humoral immunity via primary infection of other coronaviruses lasts for several months although antibody titers wane over time 13–15 . In terms of SARS‐CoV‐2 infection, there are several studies conducted in acute and early convalescence periods and they have reported that NAb titers vary depending on the severity of the primary infection and the length of time from onset 2,5,12 . In addition, Legros et al 16 reported a rapid decline in NAb titers elicited via SARS CoV‐2 infections after recovery compared with other coronaviruses infections.…”

“…In addition, it is not known whether boosting vaccination after primary infection is necessary, and if it is, the optimum time to perform this vaccination is also not known. Although there are more studies on acute phase antibody response after COVID‐19, 2,3 knowledge about long‐term immunity is still limited 4,5 . Recently, Dispinseri et al 4 performed a neutralization assay with pseudovirus and reported that most of the recovered COVID‐19 patients had detectable NAb titers up to 8 months after primary infection, despite the progressive decrease in titers in the first 2 months.…”