ABSTRACT
SARS-CoV-2 continued to spread globally along with different variants. Here, we systemically analyzed viral infectivity and immune-resistance of SARS-CoV-2 variants to explore the underlying rationale of viral mutagenesis. We found that the Beta variant harbors both high infectivity and strong immune resistance, while the Delta variant is the most infectious with only a mild immune-escape ability. Remarkably, the Omicron variant is even more immune-resistant than the Beta variant, but its infectivity increases only in Vero E6 cells implying a probable preference for the endocytic pathway. A comprehensive analysis revealed that SARS-CoV-2 spike protein evolved into distinct evolutionary paths of either high infectivity plus low immune resistance or low infectivity plus high immune resistance, resulting in a narrow spectrum of the current single-strain vaccine. In light of these findings and the phylogenetic analysis of 2674 SARS-CoV-2 S-protein sequences, we generated a consensus antigen (S6) taking the most frequent mutations as a pan-vaccine against heterogeneous variants. As compared to the ancestry SWT vaccine with significantly declined neutralizations to emerging variants, the S6 vaccine elicits broadly neutralizing antibodies and full protections to a wide range of variants. Our work highlights the importance and feasibility of a universal vaccine strategy to fight against antigen drift of SARS-CoV-2.
ABSTRACT
Hematological parameters play a key role in assessing the disease states and physiological status of birds, however the reliable information of hematological reference values for Lohmann silver in the pre- and post-laying periods is limited. Thus, the aim of this study was to research the effect of age on hematological parameters and provide reliable reference intervals for commercial Lohmann silver layer. Blood samples were obtained from 231 laying hens at different ages (5-37 wk) with 4-wk sampling intervals. A total of 12 hematological parameters including leucocytes (WBC, 109/L), red blood cell (RBC,1012/L), hemoglobin (HGB, g/L), hematocrit (HCT,%), mean corpuscular volume (MCV, fL), mean corpuscular hemoglobin (MCH, pg), mean corpuscular hemoglobin concentration (MCHC, g/L), red cell distribution width (RDW,%), platelet count (PLT,109/L), mean platelet volume (MPV, fL), platelet volume distribution width (PDW), plateletcrit (PCT, fL) were determined with a reference value advisor. One-ANOVA and Tukey test were utilized to test for significant differences of each parameter between ages. Our findings showed that these parameters were significantly affected by age, except for HCT in the pre-laying period. And reference intervals for all parameters except MCH, MCHC, MCV, MPV, and PDW in the pre-laying period were higher than that in the post-laying period. The results of this study may serve as indispensable information when diagnosing the health of Lohmann silver layer.
