ABSTRACT
Background. There are few data on immune correlation of protection from breakthrough Omicron (B.1.1.529) infection in individuals who received booster vaccines. We thus compared a neutralizing antibody titers against Omicron within the first month after the mRNA booster at the time before omicron wave between healthcare works (HCWs) who experienced Omicron breakthrough infections and HCWs without Omicron infections. Methods. We enrolled HCWs without the history of SARS-CoV-2 infection who agreed with blood sampling 2 weeks after booster vaccination at Asan Medical Center, Seoul, South Korea, between November 2021 and December 2022 (Delta dominant era). We identified breakthrough infections by performing SARS-CoV-2 RT-PCR though nasopharyngeal swab specimen in HCWs who had COVID-19-related symptoms or had known exposure to confirmed SARS-CoV-2-infected patients, between 1 February and 25 April 2022 (Omicron dominant era). SARS-CoV-2 S1-specific IgG antibody titers were measured using enzyme-linked immunosorbent assay (ELISA). Plasma levels of live-virus neutralizing antibodies were measured using a microneutralization assay with SARS-CoV-2 omicron variants. Results. Among 134 HCWs, 69 (52%) received two-dose ChAdOx1 nCoV-19 followed by BNT162b2, 50 (37%) three-dose BNT162b2, and 15 (11%) 3-dose mRNA-1273. Of them, 57 (43%) experienced breakthrough Omicron infection at median 121 days (IQR 99-147) after booster vaccination (breakthrough group), and the remaining 77 (57%) did not experience Omicron infection (non-breakthrough group). There was no significant different in 'peak' SARS-CoV-2 S1-specific IgG level between breakthrough group (median 4484.4 IU/mL) and non-breakthrough group (median 4194.9 IU/mL, p value=0.39). In addition, there was no significant difference in 'peak' neutralizing antibody titer (ID50) against Omicron between breakthrough group (median 2597.9) and non-breakthrough group (median 2597.9, p value=0.86). (Table Presented) Serum samples were obtained from 134 healthcare workers 2 weeks after booster vaccination. Samples were analysed for SARS-CoV-2 S1-specific IgG antibody titers using enzyme-linked immunosorbent assay (ELISA) and plasma levels of live-virus neutralizing antibodies using a microneutralization assay with SARS-CoV-2 omicron variants. There was no significant difference in 'peak' SARS-CoV-2 S1-specific IgG level (A) and 'peak' neutralizing antibody titer (ID50) against Omicron (B) between breakthrough group and non-breakthrough group. Conclusion. We did not find the correlation of neutralizing antibody titers about several months before infection with breakthrough Omicron infections. These data suggest rapidlywaning neutralizing titers to protect mild illnesses or asymptomaticOmicron infections several months after current booster COVID-19 vaccination in HCWs.
ABSTRACT
Background: The elbow plank is a common exercise that can easily be done at home, but its effects on physical fitness and immunocyte function in elderly people are unknown. This prior study was conducted to analyze the changes in health-related physical fitness and immunocytes in an elderly male subject after performing elbow plank exercises. Methods: The participant was a 61-year-old man who had no experience in performing the elbow plank. Elbow plank exercises were performed for 30 min a day, 5 days a week, for 4 weeks. The intensity of was checked daily with ratings of perceived exertion (RPE). His goal was to reach an RPE between 12 and 14, at which a 1 min rest was given before repeating the process with a progressively higher RPE every 10 min. Results: Compared with pre-values, (1) health related physical fitness factors increased after 4 weeks. (2) Body weight, skeletal muscle mass, and basal metabolic rate increased, whereas body fat mass and fat percentage decreased. (3) Certain variables of complete blood count showed positive changes, while others did not. Specifically, NK cells (CD56) and cytotoxicity were improved. Conclusions: This study confirmed that performing elbow plank exercises improved all factors of physical fitness and the immunocyte function in an elderly male. Therefore, 20.73 min (9.27 min of rest) of plank exercise is recommended for elderly men to prevent deterioration of physical fitness and immunocyte function while staying at home, especially during the COVID-19 pandemic.
ABSTRACT
The aims of this study are to describe the key success factors of South Korea’s response to COVID-19 and to prepare for the post-COVID-19 world in public health. The MERS-CoV outbreak in 2015 provided the country with opportunities to enhance its national public health capacity in responding to emerging diseases, particularly in the areas of governance, testing, and tracing strategies, public-private partnership, risk communication, and the legal system supporting the government’s actions. This newly established system played a key role in South Korea’s relatively successful response to COVID-19. In this study, I evaluate that response and propose public health policies with a view to preparing for the post-COVID-19 world. © 2020 by the GSPA, Seoul National University.
ABSTRACT
Background and objectives: This study analyzed the effectiveness of the online practical classes (OPC) in physical education (PE) in compliance with the ADDIE model during the COVID-19 pandemic. Materials and Methods: Participants had no prior experience in OPC and total 75 participants were enrolled in this study. This study selected 15 universities in consideration of regional equality and randomly selected two professors and three students from each university. Results: (1) The learning interventions were not feasible for team projects. (2) In the implementation phase, most learners felt that errors persisted. (3) In the evaluation phase, educators reported unenthusiastic involvement of students and the learners were merely submitting assignments. (4) An appropriate level of the effectiveness through OPC showed significantly different between educators and learners. Conclusions: The findings indicate that timely and quality feedback should be provided for the successful execution of OPC in PE;the educators should prepare ahead and reduce technical errors and motivate learners continuously. Lastly, to prepare for the new normal after COVID-19, universities should provide enough time for educators to make OPC-videos and teach students in real time to ensure consistent feedback.