The Diagnostic Value Of Antibody Detection For COVID-19 And The Analysis Of Immunity To Vaccines

Objective The occurrence and rapid spread of the new coronavirus pneumonia epidemic has brought catastrophic consequences to the world.Therefore,rapid diagnosis and treatment,as well as effective prevention methods are the hope of controlling the epidemic.This article uses the specific antibodies in the early stage to treat severe acute respiratory diseases.The research on the diagnostic value of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and the later research on the immune effectiveness of the SARS-CoV-2 vaccine are hoped to provide ideas and suggestions for clinical epidemic prevention.1.To evaluate the application value of SARS-CoV-2 specific antibody IgG and IgM detection in the diagnosis of COVID-19.2.SARS-CoV-2 vaccination work has been successively carried out in China.The vaccine mainly comes from the inactivated new coronavirus vaccine produced by the Beijing Institute of Biological Products Co.,Ltd.and Wuhan Institute of Biological Products Co.,Ltd.,and the vaccine has been vaccinated through testing.The adult anti-S protein IgG and IgM,understand and analyze the humoral immune effect of the vaccine.Methods 1.Using retrospective research methods,94 serum samples of patients diagnosed with COVID-19 from January 20 to April 16,2020 were collected as the research objects,and the control group was 161 patients with other diseases diagnosed as non-COVID-19.The patient’s serum specimen.Detect SARS-CoV-2specific IgG and IgM antibodies in serum by colloidal gold immunochromatography,and analyze the diagnostic value of antibody detection for COVID-19.2.Collect 166 blood samples from 100 adult volunteers who have been vaccinated with SARS-CoV-2 vaccine,and collect 40 blood samples that have not been vaccinated with SARS-CoV-2 vaccine as a control group,and detect 206 by magnetic particle chemiluminescence method The anti-S protein IgG and IgM antibody levels of a specimen were initially understood and analyzed for the humoral immune effect of the SARS-CoV-2 vaccine.Result1.(1)SARS-CoV-2 specific IgG and IgM antibody test results: 89 cases(94.68%)of COVID-19 patients were IgG positive,78 cases were IgM positive(82.98%),IgG/IgM(IgG and IgM)Any antibody positive is determined to be positive)91 cases(96.81%)were positive;1 case(0.62%)was positive for both IgG and IgM,1 case was single IgG positive(1.24%),and 1 case was single IgM positive(1.24%).(2)The sensitivity and specificity of SARS-CoV-2 specific IgG and IgM antibody detection for COVID-19 diagnosis: With the positive nucleic acid test as the gold standard,the sensitivity and specificity of IgG/IgM in diagnosing COVID-19 are96.81%.98.14%,accuracy of 97.65%,positive likelihood ratio of 51.95,negative likelihood ratio of 0.03,and Youden index of 0.95.The diagnostic sensitivity of IgG-positive,IgM-positive,and IgG/IgM-positive was statistically significant(P<0.01),and the diagnostic sensitivity of IgG/IgM was the highest.(3)SARS-CoV-2specific IgG and IgM antibody detection and the patient’s course of disease: 4 of the COVID patients were asymptomatic infections found on active screening,that is,the time when the patient was positive for IgG/IgM was detected earlier than the nucleic acid diagnosis Time(days of onset <0),analysis of the IgG and IgM detection conditions of patients with different courses of disease showed that the difference between IgG positive and IgM positive results was statistically significant when the onset time was 0-7 days(P<0.05).2.(1)All 66 specimens collected after the first vaccination were IgG negative,the positive rate was 0(0/66),and the IgM positive rate was 4.54%(3/66).(2)In the100 specimens collected after the second injection,the IgG positive rate was 71%(71/100),the IgM positive rate was 20%(20/100),and the total positive rate was 71%(71/100).Among the 7 specimens on the 14 th day after injection,1 case was IgG positive,that is,the positive rate was 14.29%,and the positive rate of the specimens from the 28 th day to the 35 th day was 75.27%(70/93).(3)Through statistical analysis of the IgG antibody test results(sample luminescence value/cutoff value)and positive conversion rate of the second specimen,we found that the median result for males was 4.87(2.14,9.13),and the median for females The result was 3.76(2.06,10.23),p=0.485,the difference was not statistically significant.Male IgG positive rate was64.29%(27/42),female IgG positive rate was 75.86%(44/58),but p=0.208,the difference was not statistically significant.We also divided the age groups into three segments(respectively <30 years old,30-49 years old,50 years old and above)for statistical comparison,and the median test results were 6.15(2.24,11.32),4.21(2.19,9.10)),2.28(1.41,7.29),p=0.271,the difference was not statistically significant.The positive rates were 83.33%(15/18),71.64%(48/67),53.33%(8/15),p=0.164,the difference was not statistically significant.(4)In the experiment,we found that the luminescence value of the negative result of the second blood draw of the research object was higher than the luminescence value of the control group,so we also compared the two sets of data statistically.It was found that the median result of IgG in the experimental group was 0.32(0.22,0.54),the median result of the control group was 0.12(0.11,0.14),P<0.001;the median result of IgM in the experimental group was 0.27(0.14,0.50),the control The median result of the group was 0.10(0.08,0.11),P<0.001.It shows that whether it is IgG or IgM,the difference between the results of the two groups is statistically significant.Conclusion 1.The study of 94 patients with confirmed COVID-19 and 161 patients with other diseases diagnosed as non-COVID-19 found that SAS-CoV-2specific IgG or IgM antibody detection is important in the clinical diagnosis of COVID-19 The application value is an important diagnostic and screening indicator for COVID-19.2.Detect the anti-S protein IgG and IgM antibody levels of 206 specimens by magnetic particle chemiluminescence method,understand and analyze the immune effect of the COVID-19 vaccine,it is clear that the vaccine has a high immune response in the population and has a good immune effect.