ABSTRACT
Purpose@#Neutralizing antibodies (NAbs) have been considered effective in preventing and treating viral infections. However, until now, the duration and clinical implications of antibody-mediated nature immunity in Koreans have remained unknown.Therefore, we examined NAbs levels and clinical characteristics in recovered coronavirus disease 2019 (COVID-19) patients. @*Materials and Methods@#Blood samples were collected from 143 adult patients who had been diagnosed with and had recovered from COVID-19 from February to March in 2020 at a tertiary-care university-affiliated hospital in Daegu, Korea. A plaque reduction neutralization test was conducted to analyze NAb titers. Individualized questionnaires were used to identify patient clinical information. @*Results@#The median number of days from symptom onset to the blood collection date was 109.0 (104.0; 115.0). The NAb titers ranged from 10 to 2560. The median NAb titer value was 40. Of the 143 patients, 68 (47.6%) patients had NAb titers ≥80, and 31 (21.7%) patients had NAb titers ≥160. The higher the age or disease severity, the higher the NAb titer. In univariate logistic regression, statistically significant predictors of high NAb titers (≥80) were age, myalgia, nausea or vomiting, dyspnea, and disease severity (p<0.05). Multivariable logistic regression showed that age ≥50 years (p=0.013) and moderate or higher disease severity (p<0.001) were factors associated with high NAb titers (≥80). None of the patients had reinfection of COVID-19. @*Conclusion@#All recovered patients were found to have NAbs regardless of the NAb titers maintained by natural immunity. Age and disease severity during COVID-19 infection were associated with high NAb titers.
ABSTRACT
Purpose@#Neutralizing antibodies (NAbs) have been considered effective in preventing and treating viral infections. However, until now, the duration and clinical implications of antibody-mediated nature immunity in Koreans have remained unknown.Therefore, we examined NAbs levels and clinical characteristics in recovered coronavirus disease 2019 (COVID-19) patients. @*Materials and Methods@#Blood samples were collected from 143 adult patients who had been diagnosed with and had recovered from COVID-19 from February to March in 2020 at a tertiary-care university-affiliated hospital in Daegu, Korea. A plaque reduction neutralization test was conducted to analyze NAb titers. Individualized questionnaires were used to identify patient clinical information. @*Results@#The median number of days from symptom onset to the blood collection date was 109.0 (104.0; 115.0). The NAb titers ranged from 10 to 2560. The median NAb titer value was 40. Of the 143 patients, 68 (47.6%) patients had NAb titers ≥80, and 31 (21.7%) patients had NAb titers ≥160. The higher the age or disease severity, the higher the NAb titer. In univariate logistic regression, statistically significant predictors of high NAb titers (≥80) were age, myalgia, nausea or vomiting, dyspnea, and disease severity (p<0.05). Multivariable logistic regression showed that age ≥50 years (p=0.013) and moderate or higher disease severity (p<0.001) were factors associated with high NAb titers (≥80). None of the patients had reinfection of COVID-19. @*Conclusion@#All recovered patients were found to have NAbs regardless of the NAb titers maintained by natural immunity. Age and disease severity during COVID-19 infection were associated with high NAb titers.
ABSTRACT
As of September 2020, SARS-CoV-2 has infected over 30 million people worldwide, and the death toll has now risen to 950,000. Given that Povidone-iodine (PVP-I) had consistently been showing the virucidal efficacy against various types of viruses, such as SARS-CoV, MERS-CoV, and Ebola, we conducted this study to figure out the virucidal effect against SARS-CoV-2 by using a viral plaque assay. We performed Kill-Time assays to assess the viral inactivation of SARS-CoV-2 contaminants after the application of the PVP-I product (Betadine® Throat Spray, PVP-I 0.45%). This test consisted of clean and dirty conditions and was designed to check the viral titers at a contact time of 60 seconds, which were evaluated by plaque-reduction rates in Vero cells. This PVP-I product fully achieved ≥4 log 10 reductions in viral titers under both clean and dirty conditions. This level of reduction, ≥4 log 10 (99.99%), in viral titers presented to be effective in terms of virucidal efficacy, according to the European standards, EN14476. This study revealed the virucidal efficacy of Betadine® Throat Spray against SARS-CoV-2 virus. Given that the convenience and availability of this product, we think that it may contribute to inhibit viral infection and transmissibility as an active type of personal protective equipment (PPE) by managing the hygiene of patients and medical professionals.
ABSTRACT
As of September 2020, SARS-CoV-2 has infected over 30 million people worldwide, and the death toll has now risen to 950,000. Given that Povidone-iodine (PVP-I) had consistently been showing the virucidal efficacy against various types of viruses, such as SARS-CoV, MERS-CoV, and Ebola, we conducted this study to figure out the virucidal effect against SARS-CoV-2 by using a viral plaque assay. We performed Kill-Time assays to assess the viral inactivation of SARS-CoV-2 contaminants after the application of the PVP-I product (Betadine® Throat Spray, PVP-I 0.45%). This test consisted of clean and dirty conditions and was designed to check the viral titers at a contact time of 60 seconds, which were evaluated by plaque-reduction rates in Vero cells. This PVP-I product fully achieved ≥4 log 10 reductions in viral titers under both clean and dirty conditions. This level of reduction, ≥4 log 10 (99.99%), in viral titers presented to be effective in terms of virucidal efficacy, according to the European standards, EN14476. This study revealed the virucidal efficacy of Betadine® Throat Spray against SARS-CoV-2 virus. Given that the convenience and availability of this product, we think that it may contribute to inhibit viral infection and transmissibility as an active type of personal protective equipment (PPE) by managing the hygiene of patients and medical professionals.
ABSTRACT
A century ago, more exactly 102 years ago, there was a devastating pandemic of influenza in 1918 and thereafter, periodic recurrences of pandemic events have been reported in the human population. Unfortunately, whenever it happened, the outcome was concomitant with over millions of death tolls due to considerably higher case fatality rates, compared to other infectious diseases at that time. In this regard, pandemics, which continued at irregular time intervals, give a great significance to global public health responses. However, it is far from feasibility to predict when a next pandemic will begin and how much disease burden will be despite our efforts to utilize all kinds of available scientific information and knowledge. The one clear thing is that approximately 70% of the causative agents of emerging and/or re-emerging diseases including COVID-19 (coronavirus disease 2019), which has been started from Wuhan province, China in December 2019 and has resulted in more than 4 million human cases within a few months, are viruses. Therefore, it is very important to secure fast and accurate identification methods of a causative pathogen in order to provide scientific clues and to prepare in advance for the abrupt occurrence of unknown viral diseases in a timely manner. In this review, the current status and future perspectives of the molecular technology for identification of viral pathogens such as SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) with regard to rapid public health responses in the early stage of infectious diseases including COVID-19, will be discussed.