ABSTRACT
The traceability of COVID-19 is of great importance for Epidemiological implications. Two robust and non-parametric traceability methods were employed in the study to evaluate COVID-19's traceability for the prevention of epidemics. We first corrected the initial dates for eight countries using Solow and smith's method, and then the OLE method was applied to the corrected dataset for traceability. Our model suggests that the first global case of COVID19 originated on 25 September 2019 (95%CI 23 September) and that the first case emerged in Europe and spread rapidly to neighbouring countries, expanding globally in early January 2021. Our study suggests that the spread of the epidemic may be more rapid and earlier than we thought. The two methods we use can be used in a robust traceability approach for small sample estimates, providing additional explanations for epidemic traceability studies.
ABSTRACT
Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by 2019-nCoV. Due to the physiological change in pregnancy, pregnant women are susceptible to COVID-19 and are at increased risk for adverse pregnancy outcomes, especially in the context of spread of novel variants. At present, less evidences have been obtained from randomized controlled trials on the effectiveness and safety of COVID-19 vaccine use in pregnant women, and the recommendations of COVID-19 vaccination for pregnant women vary with countries, posing challenge to the prevention and control of COVID-19 in pregnant women. This paper summarizes the progress in major research of 2019-nCoV infection in pregnancy conducted both at home and abroad, describes the harm of COVID-19 in pregnancy to pregnant women, fetuses and infants and introduces the effectiveness and safety of COVID-19 vaccination in pregnancy revealed by real world studies in order to provide reference for the related research and development of COVID-19 prevention and control strategies in pregnant women.