In order to support vaccine development, and to aid convalescent plasma therapy, it would be important to understand the kinetics, timing and persistence of SARS-CoV-2 neutralizing antibodies (NAbs), and their association with clinical disease severity. Therefore, we used a surrogate viral neutralization test to evaluate their levels in patients with varying severity of illness, in those with prolonged shedding and those with mild/asymptomatic illness at various time points. Patients with severe or moderate COVID-19 illness had earlier appearance of NAbs at higher levels compared to those with mild or asymptomatic illness. Furthermore, those who had prolonged shedding of the virus, had NAbs appearing faster and at higher levels than those who cleared the virus earlier. During the first week of illness the NAb levels of those with mild illness was significantly less (p = 0.01), compared to those with moderate and severe illness. At the end of 4 weeks (28 days), although 89% had NAbs, 38/76 (50%) in those with > 90 days had a negative result for the presence of NAbs. The Ab levels significantly declined during convalescence (> 90 days since onset of illness), compared to 4 to 8 weeks since onset of illness. Our data show that high levels of NAbs during early illness associated with clinical disease severity and that these antibodies declined in 50% of individuals after 3 months since onset of illness.

In order to support vaccine development, and to aid convalescent plasma therapy, it would be important to understand the kinetics, timing and persistence of SARS-CoV2 neutralizing antibodies (NAbs), and their association with clinical disease severity. Therefore, we used a surrogate viral neutralization test to evaluate their levels in patients with varying severity of illness, in those with prolonged shedding and those with mild/asymptomatic illness at various time points.Patients with severe or moderate COVID-19 illness had earlier appearance of NAbs at higher levels compared to those with mild or asymptomatic illness. Furthermore, those who had prolonged shedding of the virus, had NAbs appearing faster and at higher levels than those who cleared the virus earlier. During the first week of illness the NAb levels of those with mild illness was significantly less (p=0.01), compared to those with moderate and severe illness. At the end of 4 weeks (28 days), although 89% had Nabs, 38/76 (50%) in those with >90 days had a negative result for the presence of NAbs. The Ab levels significantly declined during convalescence (>90 days since onset of illness), compared to 4 to 8 weeks since onset of illness. Our data show that high levels of NAbs during early illness associated with clinical disease severity and that these antibodies declined in 50% of individuals after 3 months since onset of illness.

In order to understand the kinetics, timing and persistence of SARS-CoV2 neutralizing antibodies (Nabs) we used a surrogate viral neutralization test to evaluate their levels in patients with varying severity of illness, in those with prolonged shedding and those with mild/asymptomatic illness at various time points. Patients with severe or moderate COVID-19 illness had earlier appearance of Nabs at higher levels compared to those with mild or asymptomatic illness. Furthermore, those who had prolonged shedding of the virus, had Nabs appearing faster and at higher levels than those who cleared the virus earlier. Although all individuals appeared to be antibody positive by end of week 5, the positivity rates declined thereafter, especially in those who had mild or asymptomatic illness.

Background Clinical manifestations of coronavirus disease 2019 (COVID19) can vary from asymptomatic to profusely symptomatic due to many factors. Having data on the clinical characteristics of the affected patients is important for the screening and diagnosis of COVID-19. Main objective of this study is to evaluate the clinical and epidemiological characteristics and outcomes of patients with COVID-19 admitted to six treatment centres in Sri Lanka. Methods For the specific epidemic situation of COVID-19, we chose to conduct a descriptive retrospective study from six treatment centres in the country between March 10, 2020 and May 30, 2020. Results The study included 431 laboratory confirmed patients with COVID-19. Of them, 335 (78.2%) were males and their mean age was 37 years. Most patients (373: 86.5%) had had close contact with COVID-19 positive patients. The majority were asymptomatic (243: 56.3%) and of the symptomatic patients, the most common symptom was sore throat (81, 19%), followed by cough (72, 17%), headache (72, 17%), fever (50, 12%), and nasal discharge (36, 8%). Eight patients required either high dependency care or intensive unit care two of them succumbed to the illness (0.5%). Hydroxychloroquine (HCQ) was used as a treatment in 248 patients and they had a significantly longer (17.6 days) duration of hospital stays compared those who were not treated (13.6 days) with HCQ. When the HCQ was not used as a treatment, asymptomatic individuals had significantly shorter durations of hospital (11.1 days) stays compared to symptomatic individuals (14.3 days). Conclusions The majority of patients remained asymptomatic during the course of illness. The most common symptom was sore throat, seen in one fifth of patients, followed by cough, and headache. Our study also indicated the possibility of reduced viral clearance and hence longer duration of hospital stays with HCQ.

No abstract