ABSTRACT
As the third year of the global COVID-19 pandemic, vaccination remains the most effective tool against infections and symptomatic illness. Comprehension regarding immunity to SARS-CoV-2 is limited, and the durability of immune responses after vaccination is currently not clear. In this study, we randomly collected 395 questionnaires to analyze the current state of COVID-19 vaccination. At the same time, the serum of 16 individuals who had received two doses of the COVID-19 vaccine were collected at different times before and after the booster vaccination. We analyzed the dynamic changes of SARS-CoV-2 S-specific binding antibodies in serum and immunological indicators. By collecting public opinion surveys and analyzing variational trends of SARS-CoV-2 S-specific binding antibodies and immune indicators after COVID-19 booster vaccination, we endeavored to demonstrate the concerns affecting people's booster vaccinations, as well as the frequency, timing, and necessity of COVID-19 booster vaccinations. The analysis of antibody results in 16 vaccinated volunteers showed that the antibody concentration decreased six months after the second dose and the protective effect of the virus was reduced. The third dose of COVID-19 vaccination is necessary to maintain the antibody concentration and the protective effect of the virus. The vaccination with the vaccine booster depends not only on the time interval but also on the initial concentration of the SARS-CoV-2 S-specific binding antibody before the booster. Our study has important implications for raising public awareness of vaccinating against SARS-CoV-2 and the necessity of COVID-19 booster vaccinations.
ABSTRACT
The early detection and differential diagnosis of respiratory infections increase the chances for successful control of COVID-19 disease. The nucleic acid RT-PCR test is regarded as the current standard for molecular diagnosis. However, the maximal specificity confirmation target ORF1ab gene is considered to be less sensitive than other targets in clinical application. In addition, recent evidence indicated that the initial missed diagnosis of asymptomatic patients with SARS-CoV-2 and discharged patients with "re-examination positive" might be due to low viral load, and the ability of rapid mutation of SARS-CoV-2 also increases the rate of false-negative results. Moreover, the mixed sample nucleic acid detection is helpful in seeking out the early community transmission of SARS-CoV-2 rapidly, but the detection kit needs ultra-high detection sensitivity. Herein, the lowest detection concentration of different nucleic acid detection kits was evaluated and compared to provide direct evidence for the selection of kits for mixed sample detection or make recommendations for the selection of validation kit, which is of great significance for the prevention and control of the current epidemic and the discharge criteria of low viral load patients.
Subject(s)
Limit of Detection , Real-Time Polymerase Chain Reaction/methods , SARS-CoV-2/isolation & purification , Adolescent , Adult , Child , False Negative Reactions , Female , Humans , Male , Middle Aged , SARS-CoV-2/genetics , Young AdultABSTRACT
The global outbreak of SARS-CoV-2 spread rapidly throughout the world which transmitted among humans through various routes. Asymptomatic (carriers) and possible fecal-oral transmission, resulted into a large-scale spread. These issues pose great challenges to disease diagnosis and epidemic control. We obtained data on 29 cases of COVID-19 patients in Jinan, China, and reported the clinical data of asymptomatic patients confirmed with stool samples positive. Some patients with gastrointestinal infections are secondary to pulmonary infections, and during the patients' recovery period, the virus may still existin the patient's gastrointestinal tract over 7 days. We combined with epidemiological and clinical data of asymptomatic patients to analyze the possible routes of viral transmission and infection, including eyes-nose, hands-eyes, fecal-oral, and eyes-oral, et al., thus first presented the two-way transmission through eyes-oral. Through associating infection symptoms with the transmission routes of virus and the patient course of the disease, we expect to provide guidelines for clinical diagnosis and the basis for suppressing the spread of the virus and antiviral treatment.