Heterologous vaccination strategy for containing COVID-19 pandemic (preprint)

An unequitable vaccine allocation and continuously emerging SARS-CoV-2 variants pose challenges to contain the pandemic, which underscores the need for licensing more vaccine candidates, increasing manufacturing capacity and implementing better immunization strategy. Here, we report data from a proof-of-concept investigation in two healthy individuals who received two doses of inactivated whole-virus COVID-19 vaccines, followed by a single heterologous boost vaccination after 7 months with an mRNA vaccine candidate (LPP-Spike-mRNA) developed by Stemirna Therapeutics. Following the boost, Spike-specific antibody (Ab), memory B cell and T cell responses were significantly increased. These findings indicate that a heterologous immunization strategy combining inactivated and mRNA vaccines can generate robust vaccine responses and therefore provide a rational and effective vaccination regimen.

Prevention and Control Strategies Based on the Epidemiology of Imported COVID-19 in Mainland China (preprint)

Background: Imported COVID-19 cases are a serious public health problem worldwide. However, limited epidemiologic information of imported cases affects the choice of prevention and control strategies.Methods: In this study, we collected data from 22 January 2020 to 21 April 2020 related to imported COVID-19 cases in Mainland China from the daily public data of the National Health Commission and the provincial health commissions.Findings: A total of 1610 cases of COVID-19 were imported from 49 countries and regions to 27 provincial administrative regions. 79.81% cases were imported from European countries and the United States. Before 29 March, the imported cases were mainly from the United States (27.66%) and United Kingdom (42.55%). After 29 March 2020, the daily newly imported cases from Russia rapidly growed. After 12 April, the number of daily newly imported cases gradually decreased and remained at a low level (12±7 cases per day). Airport entry was encouraged and ground crossing entry was limited with the help of dynamic surveillance of the weekly proportion of confirmed cases at ports. 54.04% imported confirmed cases were in the asymptomatic incubation period on arrival in Mainland China. The compulsory centralized quarantine decreased the risk of onward transmission from imported cases compared to home quarantine ( P <0.05).Interpretation: Prevention and control strategies based on the epidemiological characteristics of imported cases effectively protected Mainland China against reintroduction of the virus and re-initiation of the epidemic when the epidemic was still in a surge worldwide. Such measures included: exit screening, entry screening, and compulsory centralized quarantine of all inbound travelers followed by strict contact tracing. The experiences from Mainland China provide an example of effective measures to reduce transmission of imported COVID-19 cases.Funding Statement: Shanghai Science and Technology Commission, Pudong Health Bureau of Shanghai and Krebsliga Schweiz, BIL KFS. Declaration of Interests: None to be declared.

Single-cell screening of SARS-CoV-2 target cells in pets, livestock, poultry and wildlife (preprint)

A few animals have been suspected to be intermediate hosts of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, a large-scale single-cell screening of SARS-CoV-2 target cells on a wide variety of animals is missing. Here, we constructed the single-cell atlas for 11 representative species in pets, livestock, poultry, and wildlife. Notably, the proportion of SARS-CoV-2 target cells in cat was found considerably higher than other species we investigated and SARS-CoV-2 target cells were detected in multiple cell types of domestic pig, implying the necessity to carefully evaluate the risk of cats during the current COVID-19 pandemic and keep pigs under surveillance for the possibility of becoming intermediate hosts in future coronavirus outbreak. Furthermore, we screened the expression patterns of receptors for 144 viruses, resulting in a comprehensive atlas of virus target cells. Taken together, our work provides a novel and fundamental strategy to screen virus target cells and susceptible species, based on single-cell transcriptomes we generated for domesticated animals and wildlife, which could function as a valuable resource for controlling current pandemics and serve as an early warning system for coping with future infectious disease threats.

CT features of 2019-novel coronovirus pneumonia: SARS and MERS literature review and analysis of CT features of two confirmed 2019-novel coronavirus pneumonia cases / 中华危重病急救医学

Objective@#To analyze the CT manifestations of the 2019 novel coronavirus pneumonia (NCP) combined with severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) literature review, and to summarize the characteristics of CT imaging, so as to improve the ability of rapid and accurate diagnosis.@*Methods@#CT manifestations of two confirmed cases of NCP were reported, meanwhile the literatures on SARS and MERS imaging performance were reviewed and summarized.@*Results@#The two cases of NCP were both in acute stage, the CT imaging showed multiple and scattered ground-glass opacity (GGO) in both lungs, which is similar to the CT performance of SARS and MERS in acute stage.@*Conclusions@#The CT features of 2019 novel coronavirus pneumonia are similar to SARS and MERS. It has certain characteristics and changes rapidly with the course of the disease. In the acute stage, GGO and paving stone sign were the main manifestations. In the acute phase, GGO and crazy paving are the main manifestations. In the progress stage, the interlobular septal thickening and consolidation appeared. During the absorption period, the lesions disappeared or fibrosis was left behind, with lung structure distortion and bronchiectasis. Lymphadenopathy and hydrothorax were rare.