ABSTRACT
【Objective】 To analyze the dynamics of specific SARS-CoV-2 IgG antibodies in blood donors in Fuzhou area after receiving booster doses of inactivated COVID-19 vaccine and breakthrough infections, and to provide evidence for the timing of the collection of specific immune plasma or convalescent plasma and the subsequent vaccine doses. 【Methods】 A total of 109 volunteers who received the first booster dose of inactivated COVID-19 vaccine and 102 volunteers who experienced breakthrough infections were recruited at Fujian Blood Center from October to November 2021. Blood samples were collected at eight time points: 14 (11, 20) days before the booster dose (Time0), 14 (10, 23) days after the booster dose (Time1), 53 (45.5, 61) days after the booster dose (Time2), 88 (78, 101.5) days after the booster dose (Time3), 124 (112.5, 138.5) days after the booster dose (Time4), 158 (146, 174) days after the booster dose (Time5), 194 (179.5, 214) days after the booster dose (Time6) and within one month after the breakthrough infection (Time7). Serum SARS-CoV-2 IgG antibodies were detected using a chemiluminescence immunoassay. The dynamics of antibody levels were analyzed and the effects of age, gender, weight, BMI, blood type and smoking on antibody levels were also analyzed. 【Results】 The positive rate of SARS-CoV-2 IgG antibodies was 53.2% (58/109) at Time0, 100% (109/109) at Time1, and 95.4% (104/109) at Time6. The antibody levels were significantly higher at Time1 and Time6 than at Time0 (P0.05). The IgG antibody level at Time7 was 2.07 times than that at Time1 (P0.05). The IgG antibody level in breakthrough infection group was significantly higher than that in non-breakthrough infection group (P<0.001). 【Conclusion】 Booster doses of inactivated COVID-19 vaccine and breakthrough infections can stimulate stronger immune responses in the body. It is recommended to collect specific immune plasma or convalescent plasma within one month after breakthrough infections or booster doses of COVID-19 vaccine for special purposes. The timing of subsequent vaccine doses should be based on the dynamics of antibody levels. It is necessary to continuously monitor antibody levels to provide evidence for subsequent vaccine doses.
ABSTRACT
【Objective】 To explore the reasons for wrong connection between anticoagulant and normal saline solution during apheresis platelet donation, as well as the preventive measures, so as to ensure the safety of apheresis platelet donors. 【Methods】 Manual checking in the first phase (December 2008 to September 2016) was compared with double checking (manual checking plus information system) in the second phase (October 2016 to October 2020) via bilateral testing using Fisher's Exact Test to study pre-post-improvement differences. 【Results】 The incidence of solution connection errors during apheresis platelet donation in the first phase was 1.02/10 000, and the error incidence between Amicus and Trima + Mcs®+ blood cell separator was statistically significant (P<0.05). The total incidence of errors between the first and second phases was not statistically significant (P>0.05). After the performance of double checking in the second phase, no wrong connection of anticoagulant and saline solution occurred. 【Conclusion】 The double checking method assisted by manual and information system can effectively prevent the wrong connection between anticoagulant and normal saline solution.