RESUMEN
The COVID-19 pandemic, triggered by severe acute respiratory syndrome coronavirus 2, has affected millions of people worldwide. Much research has been dedicated to our understanding of COVID-19 disease heterogeneity and severity, but less is known about recovery associated changes. To address this gap in knowledge, we quantified the proteome from serum samples from 29 recuperated COVID-19 patients and 29 age-, race-, and sex-matched healthy controls. Many proteins from pathways known to change upon acute COVID-19 illness, such as from the complement cascade, coagulation system, inflammation and adaptive immune system, had returned to levels seen in healthy controls. In comparison, we identified 22 and 15 proteins with significantly elevated and lowered levels, respectively, amongst recuperated COVID-19 cases compared to healthy controls. Some of the changes were similar to those observed for the acute phase of the disease, i.e. elevated levels of proteins from hemolysis, the adaptive immune systems, and inflammation. In contrast, some changes opposed those in the acute phase, e.g. elevated levels of CETP and APOA1 which function in lipid/cholesterol metabolism, and decreased levels of proteins from the complement cascade (e.g. C1R, C1, and VWF), the coagulation system (e.g. THBS1 and VWF), and the regulation of the actin cytoskeleton (e.g. PFN1 and CFL1) amongst recuperated COVID-19 cases. We speculate that some of these changes might originate from transient decreases in platelet counts upon recovery from the disease. Finally, we observed race-specific changes, e.g. with respect to immunoglobulins and cholesterol-metabolism-related proteins.
RESUMEN
ImportanceUniversities are unique settings with large populations, congregate housing, and frequent attendance of events in large groups. However, the prevalence of previous infection with SARS-CoV-2 in university students, including symptomatic and asymptomatic disease, is unknown. ObjectiveTo determine the prevalence of previous infection, risk factors for infection, and the prevalence of persistent symptoms following infection among university students. DesignThis was a cross-sectional study that surveyed students about demographics, risk factors, and symptoms, and simultaneously tested their saliva for IgA antibodies to SARS-CoV-2. To estimate the prevalence of previous infection we adjusted our intentional sample of a diverse student population for year in school and age to resemble the composition of the entire student body, and adjusted for the imperfect sensitivity and specificity of the antibody test. Univariate and multivariate analysis was used to identify independent risk factors for infection. SettingA large public university in Athens, Georgia between January 22 and March 22, 2021. ParticipantsUndergraduate and graduate students; 488 completed the survey, 432 had a valid antibody result. and 428 had both. ExposurePrevious infection with SARS-CoV-2 based on measurement of IgA antibodies in saliva and adjustment for sample characteristics and test accuracy. Main Outcomes and MeasuresThe primary outcome was the estimated prevalence of previous infection with SARS-CoV-2. Secondary outcomes were independent risk factors for infection, and the prevalence of persistent symptoms among persons reporting a previous symptomatic infection. ResultsThe estimated prevalence of previous infection for 432 participants with valid antibody results was between 41% and 42%. Independent risk factors for infection included male sex, having a roommate with a known symptomatic infection, and having 2 or fewer roommates. More frequent attendance of parties and bars was a univariate risk factor, but not in the multivariate analysis. Of 122 students reporting a previous symptomatic infection, 14 (11.4%) reported persistent symptoms a median of 132 days later. Conclusions and RelevancePrevious infection with SARS-CoV-2, both symptomatic and asymptomatic, was common at a large university. Measures that could prevent resurgence of the infection when students return to campus include mandatory vaccination policies, mass surveillance testing, and testing of sewage for antigen to SARS-CoV-2. Key PointsO_ST_ABSQuestionC_ST_ABSWhat is the prevalence of previous infection with SARS-CoV-2 and the prevalence of persistent symptoms in university students? FindingsIn this sample of 432 students who provided saliva for IgA antibodies, we estimate that 41% to 42% had evidence of previous infection. Of 122 reporting a previous symptomatic infection, 14 (11%) were still symptomatic a median of 132 days later. MeaningSymptomatic and asymptomatic infections with SARS-CoV-2 are common among university students, and a significant percentage had persistent symptoms over a long duration.
RESUMEN
The development of a safe and effective vaccine is a key requirement to overcoming the COVID-19 pandemic. Recombinant proteins represent the most reliable and safe vaccine approach but generally require a suitable adjuvant for robust and durable immunity. We used the SARS-CoV-2 genomic sequence and in silico structural modelling to design a recombinant spike protein vaccine (Covax-19). A synthetic gene encoding the spike extracellular domain (ECD) was inserted into a baculovirus backbone to express the protein in insect cell cultures. The spike ECD was formulated with Advax-SM adjuvant and first tested for immunogenicity in C57BL/6 and BALB/c mice. The Advax-SM adjuvanted vaccine induced high titers of binding antibody against spike protein that were able to neutralise the original wildtype virus on which the vaccine was based as well as the variant B.1.1.7 lineage virus. The Covax-19 vaccine also induced potent spike-specific CD4+ and CD8+ memory T-cells with a dominant Th1 phenotype, and this was shown to be associated with cytotoxic T lymphocyte killing of spike labelled target cells in vivo. Ferrets immunised with Covax-19 vaccine intramuscularly twice 2 weeks apart made spike receptor binding domain (RBD) IgG and were protected against an intranasal challenge with SARS-CoV-2 virus 2 weeks after the second immunisation. Notably, ferrets that received two 25 or 50g doses of Covax-19 vaccine had no detectable virus in their lungs or in nasal washes at day 3 post-challenge, suggesting the possibility that Covax-19 vaccine may in addition to protection against lung infection also have the potential to block virus transmission. This data supports advancement of Covax-19 vaccine into human clinical trials.
RESUMEN
BackgroundThe COVID-19 pandemic has resulted in a significant diversion of human and material resources to COVID-19 diagnostics, to the extent that testing of viral pathogens normally contributing to seasonal respiratory tract infections have been markedly neglected. The global health burden due to influenza viruses and co-infection in COVID-19 patients remains undocumented but clearly pose serious public health consequences. To address these clinical and technical challenges, we have optimized and validated a highly sensitive RT-PCR based multiplex assay for the detection of SARS-CoV-2, Influenza A and B viruses in a single test. MethodsThis study evaluated clinical specimens (n=1411) that included 1019 saliva and 392 nasopharyngeal swab (NPS) samples collected in either healthcare or community setting. Samples were tested using two assays: FDA-EUA approved SARS-CoV-2 assay that targets N and ORF1ab gene, and the PKamp RT-PCR based assay that targets SARS-CoV-2, Influenza viruses A and B. The limit of detection (LoD) studies was conducted as per the FDA guidelines using SARS-CoV-2 and Influenza A and B reference control materials. ResultsOf the 1019 saliva samples, 17.0% (174/1019) tested positive for SARS-CoV-2 using either assay. The detection rate for SARS-CoV-2 was higher with our multiplex assay compared to SARS-specific assay [91.9% (160/174) vs. 87.9% (153/174)], respectively. Of the 392 NPS samples, 10.4% (41/392) tested positive for SARS-CoV-2 using either assay. The detection rate for SARS-CoV-2 was higher with our multiplex assay compared to SARS-specific assay [97.5% (40/41) vs. 92.1% (39/41)], respectively. The Ct values for SARS-CoV-2 were comparable between the two assays, whereas the Ct values of the housekeeping gene was significantly lower with multiplex assay compared to SARS-specific assay. The LoD was established as 60 copies/ml for SARS-CoV-2 and 180 copies/ml for Influenza A and B viruses for both saliva and NPS samples. ConclusionThis study presents clinical validation of a multiplex PCR assay for testing SARS-CoV-2, Influenza A and B viruses, using NPS and saliva samples, and demonstrates the feasibility of implementing the assay without disrupting the existing laboratory workflow. This novel assay uses the same instruments, sample types, supplies, and laboratory personnel as needed for the testing of SARS-CoV-2 virus.