ABSTRACT
@#At present,the most commonly used method for detecting hemagglutinin(HA)content in influenza vaccines is still single-radial immunodiffusion(SRID). However,the preparation of standards required by this method takes a long time,usually 2 ～ 3 months. Therefore,how to quantitatively analyze HA accurately has always been a difficult problem in the detection of HA content in the situation that reference products can not be obtained at the early stage of the pandemic influenza. High performance liquid chromatography(HPLC)has its own characteristics of rapidity,high sensitivity,good repeatability and high accuracy,which can rapidly determine HA content by using different separation principles and has been widely used in the detection of HA content in influenza vaccine. This paper reviewed the research progress of the application of HPLC in the determination of HA content in influenza vaccine.
ABSTRACT
Objective@#Quadrivalent influenza vaccines contain two lineages of type B virus, this study aimed to assess whether the result of single radial immunodiffusion (SRID) are accurate. The cross-interference of two type B hemagglutinins remains unknown.@*Methods@#We detected the vaccine samples developed by Jiangsu GDK Biological Technology Co., ltd by SRID.@*Results@#There was no significant difference between the HA content of antigen reagent, bulk sample and mixed sample of two B bulk within 10 to 40 μg/ml (P>0.05). Then each hemagglutinin B was diluted respectively by other three HA, 30 μg/ml, the other hemagglutinin B or phosphate buffer solution were measured within 10-160 μg/ml. Within 10-40 μg/ml, the HA content was proportional to the diameters of immunodiffusion (R2=0.998), while within the higher content range, a ternary linear regression equation fitted best (R2=0.999).@*Conclusions@#No cross-interference between B/Brisbane and B/Phuket was found in SRID within both detection ranges.
ABSTRACT
Purpose: The management of burn patients is always challenging for the clinician due to high risk of bacterial sepsis, multi‑organ failure and death. Our objective was to study complement activation, C3 and interleukin‑6 (IL‑6) levels in burn patients and evaluate their role as prognostic markers. Materials and Methods: A total of 63 burn patients and 60 healthy controls were included in this study. Blood was collected from patients within 24 h and at 7th day of injury. Complement activation was determined by crossed electrophoresis and counter‑current immunoelectrophoresis. C3 levels were measured using a single radial immunodiffusion. IL‑6 was detected by ELISA. Results: All patients showed initial complement activation. Mean C3 levels showed an inverse correlation with the severity of burn. Patients with ≥20% burns had lower C3 than the controls (P < 0.001) and those with <20% burns (P < 0.001). Patients with ≥40% burns had activated complement and low C3 in 2nd week; they subsequently developed infection. Complement was inactive and C3 levels recovered in patients with <40% burns. The non‑survivors showed significantly lower C3 than the survivors (P < 0.05) in 2nd samples. Patients who developed infection had C3 significantly lower than those who remained free of infection (P < 0.05). All patients showed initial elevation in IL‑6 levels. Patients with ≥60% burns had significantly higher IL‑6 than controls (P < 0.001) and those with <60% burns (P < 0.001). Non‑survivors had higher IL‑6 than survivors in both samples (P < 0.001). Patients who developed infection showed significantly higher IL‑6 in 2nd samples than those without infection (P < 0.001). Conclusions: Complement activation, C3 and IL‑6 levels correlated well with the severity of injury and development of infection in burn patients. These parameters can be used to predict the onset of infection, septicaemia and mortality in burn patients.
ABSTRACT
Objective To establish a method for rapid preparation of antiserum against influenza virus (H7N9) hemagglutinin,and to study the possibility of using it in single radial immunodiffusion (SRID) assay for quantitative detection of antigen in H7N9 influenza vaccine.Methods Hemagglutinin proteins expressed in eukaryotic cells were used to immunize sheep.Serum samples were collected to detect antibody titers by ELISA and double immunodiffusion assay.Different concentrations of antiserum were used in SRID assay to get the optimized concentration.Results After 4 times of immunization,the antiserum titers achieved 1 ∶ 1 000 000 and 1 ∶ 32 as indicated by ELISA and double immunodiffusion assay,respectively.The antiserum could form a clear precipitation line in SRID assay.The detection of antigen in the range of 10 to 40 μg/ml showed good linearity in the standard curve.The antigen titers in six batches of H7N9 vaccine detected by this SRID assay were identical with those by SDS-PAGE assay.Conclusion The antiserum against H7N9 hemagglutinin for SRID assay was developed successfully,and could be used as a reagent for the quantitative detection of antigen in H7N9 influenza vaccine.
ABSTRACT
Objective To study the possibility of using heterogeneous antiserum in single radial immunodiffusion (SRID) for quantitative detection of HA in H7N9 influenza vaccine product when H7N9-specific antiserum is not available in order to establish a testing method for the detection of H 7N9 antigen in any urgent situation.Methods Antisera specific for H7N1, H7N2, H7N3 and H7N7 were obtained from NIBSC and used for SRID assay .Amino acid sequences of hemagglutinins were comparatively analyzed be-tween H7N9 virus and other viruses used to prepare heterogeneous antiserum .The titers of antisera against H7N9 and their homogenous antigens were detected by double immunodiffusion method .Based on the results of homology analysis and cross-reaction, a suitable antiserum was selected and its applicability was further validated by the SRID assay using H7N9 antigen.Results Influenza A virus subtype H7N3 that used for preparation of 07/278 antiserum showed the highest HA homology with H7N9 (97.14%).The titer of 07/278 antiserum against H7N9 antigen was 1 ∶8 as detected by double immunodiffusion assay .The H7N9 anti-gen and the 07/278 antiserum could form a clear precipitation line in SRID assay .The detection of H7N9 antigen in the range of 10 to 40μg/ml showed a good linearity in the standard curve .Conclusion The 07/278 antiserum from NIBSC can be used as an alternative reagent for the quantitative detection of hemaggluti -nin in H7N9 influenza virus vaccine .