COVID-19 is an acute respiratory infectious disease caused by 2019-nCoV, which has become a major global public health event and a serious threat to human health. So far, specific antiviral drugs, safe and effective vaccines for 2019-nCoV are still under development, so there is an urgent need to find alternative strategies for the treatment of COVID-19. Convalescent plasma(CP) contains high titer neutralizing antibodies from patients recovering from infectious diseases, which has been used in the treatment of major infectious diseases such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), and achieved satisfactory clinical results. Therefore, CP from COVID-19 patient is a meaningful choice for the treatment of severe or life-threatening COVID-19 patients, but its potential risks need to be studied. This review focuses on the clinical mechanism, collection points, clinical application and potential benefits and risks of clinical treatment of CP from COVID-19 patients, which will provide reference for the clinical application of CP from COVID-19 patients.

Objective:To explore the feasibility and effectiveness of the construction of urban unmanned aerial vehicle (UAV) blood distribution system, and to provide a novel way for the distribution of emergency blood.Methods:The study was completed in Hangzhou from April 2019 to January 2021, and the main participants were from the Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang Province Blood Center and Hangzhou Fast Ant Network Technology Co., Ltd. Firstly, an unmanned aircraft delivery system was built for urban emergency blood and a special blood storage box for drones were developed. The drone was used to deliver blood products from Zhejiang Province Blood Center to Binjiang Campus, the Second Affiliated Hospital of Zhejiang University School of Medicine, and the following indicators were obtained: (1) flight time of the drone blood delivery; (2) real-time temperature of blood products during transportation; (3) Baidu map software was used to measure the blood delivery time of road traffic, which was compared with the flight time of the drone.Results:The urban drone blood delivery system consists of intelligent logistics drones, cryogenic blood storage tanks, unmanned logistics hub stations, and cloud-based operation control platforms. The drone route distance from Zhejiang Provincial Blood Center to Binjiang Campus, the Second Affiliated Hospital of Zhejiang University School of Medicine was 2.36±0.06 km, and the ground distance was 5.8 km, with 27 flights from April 12, 2019 to January 29, 2021, and the drone flight time was, shorter than the road travel time for a round trip [(6.37±0.35) min vs. (17.00±1.94) min]. At different time points of the day, UAV blood delivery could save 15.98-4.28 min, with an average saving of 10.62±1.87 min. Conclusions:Urban UAV blood delivery systems have the advantages of being fast, unaffected by ground traffic conditions, and can ensure the safety of blood products during transportation, and are worthy of further exploration.

【Objective】 To explore the viability and advantages of drones in blood emergency delivery. 【Methods】 The delivery of emergency blood by drones to the Second People′s Hospital of Yuhang District(referred as Yuhang Hospital) and the Second Affiliated Hospital of Zhejiang University Medical College (referred as Binjiang Hospital) was analyzed retrospectively. The 8: 00-24: 00 traffic condition, at the interval of 2h, of working days were inquired by Baidu Map in order to compare the driving time with drone flight time. The temperature of RBCs and platelets during drone flight were monitored, and take-off and landing temperature were compared. 【Results】 47 deliveries (a total of 192 bags, 295 U) of suspended RBCs and 35 deliveries (a total of 113 bags, 159.5 therapeutic dose) of platelets were, respectively, conducted to Yuhang Hosital and Binjiang Hospital. Two transfer stations for battery charging were needed during the delivery to Yuhang Hospital, and the average one-way time by driving was similar with by drones(50 vs 55 min), without any superiority in time-efficiency. Binjiang Hospital, however, benefited from this drone delivering(driving 10mins vs drone 6 mins). As round-trip delivery for emergency blood was saved, it’s economical for the hospital to get the time-sensitive blood timely. The temperature of suspended RBCs and platelets during flight was between 2.1~7.9 ℃ and 20.2~24.2 ℃, with temperature difference at 0.3~3.7 ℃ and 0.3~3.6℃, respectively. 【Conclusion】 Drones, with good application prospects, can be applied in emergency blood delivery, and further study is needed to improve the time-efficiency and cold chain monitoring system.