ABSTRACT
Following the original severe acute respiratory syndrome coronavirus 2 strain (Wuhan-Hu-1) in December 2019, the Delta variant in May 2021 and the Omicron variant in December 2021 were classified as variants of concern. The pandemic has been ongoing for more than two years, and the three-dose vaccination rate has reached approximately 50% in Korea. We analyzed anti-S antibodies (Abs) and neutralizing Abs (NAbs) in 32 healthcare workers at a university hospital, focusing on the first to third doses of ChAdOx1-ChAdOx1-BNT162b2, which is the most common vaccination regimen in Korea. Antibodies were analyzed at eight time points according to the vaccine regimen. The first to third doses of ChAdOx1-ChAdOx1-BNT162b2 produced high Ab concentrations; NAb concentrations after the third dose were predicted to remain high for a longer period than those after the first and second doses. The effectiveness of a second dose of ChAdOx1 in the real world was demonstrated by analyzing samples collected during an outbreak that occurred in the study period, 4-5 months after the second dose. The relative risk ratio was 88.0%, and the efficacy of the second ChAdOx1 dose was 12.0% (P<0.05). Therefore, maintaining appropriate Ab concentrations through regular vaccination will help protect against coronavirus disease-19.
Subject(s)
BNT162 Vaccine , COVID-19 , COVID-19/prevention & control , Health Personnel , Humans , Longitudinal Studies , Prospective Studies , SARS-CoV-2/genetics , Vaccines, Synthetic , mRNA VaccinesABSTRACT
OBJECTIVES: This study investigated the factors influencing unmet healthcare needs of people during the early stage of the COVID-19 pandemic in Seoul, South Korea. The findings help to identify people who have difficulty accessing healthcare services during a pandemic situation. DESIGN: We conducted a cross-sectional study using a proportionate quota sampling method according to five major districts, sex and age, using an online survey. We analysed the key characteristics of influencing factors of unmet healthcare needs based on the Andersen behavioural model of healthcare utilisation: predisposing factors (eg, sex, age), need factors (eg, health status, illness) and enabling factors (eg, income, efficacy belief). SETTING: The questionnaire was sent via email and mobile text messages from the end of April to the beginning of May 2020 during the first wave of the COVID-19 pandemic. PARTICIPANTS: A sample of 813 respondents was used, and the respondent information was anonymised in the analysis process. RESULTS: For the predisposing factors, sex, age, education level and occupational cluster were associated with unmet needs for healthcare. Chronic diseases and mental health were the influencing factors as an enabling factor that exerted an influence on the unmet need for healthcare in South Korea. Women, younger persons, those with lower education and persons with white-collar jobs were more likely to experience unmet healthcare needs. In addition, the more chronic diseases people had, the more COVID-19 negatively affected them mentally; and the more people felt fear of COVID-19, the higher chances they experienced unmet healthcare needs. CONCLUSION: Government and policymakers are guided to draw out measures such as health communication and telemedicine to reduce the unmet healthcare needs during the pandemic and to recognise the different influencing factors.