ABSTRACT
This corrects the article DOI: 10.1038/mi.2017.81.
ABSTRACT
This study addresses observations made in view of testing in practice the guideline in the European Pharmacopoeia (EP) on omitting the rat potency test for release of polio containing vaccines. In general, use of the guideline is valid and the D-antigen ELISA can indeed be used as an in vitro alternative for the in vivo test. However, the set-up of the ELISA is crucial and should include detection of antigenic site 1 in polio serotype 3 as destruction of that site by trypsin results in a reduced rat potency. Antigenic site 1 in polio serotype 2 may also be modified by trypsin, but the cleavage of viral protein 1 (VP1) did not affect the rat potency. Therefore, any antigenic site, except site 1, can be used for detection of polio serotype 2. It is advised to include testing of the effect of trypsin treatment in the EP-guideline. This allows polio vaccine manufacturers to check whether their in-house ELISA needs improvement.
Subject(s)
Biological Assay , Enzyme-Linked Immunosorbent Assay , Poliovirus Vaccine, Inactivated/immunology , Poliovirus/drug effects , Trypsin/pharmacology , Animals , Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , Biosensing Techniques , Capsid Proteins/drug effects , Chlorocebus aethiops , Dose-Response Relationship, Immunologic , Europe , Hot Temperature , Poliovirus/immunology , Poliovirus/isolation & purification , Poliovirus/pathogenicity , Practice Guidelines as Topic , Rats , Vero Cells , Virulence/drug effectsABSTRACT
PURPOSE: In this study, modulation of the immune response against diphtheria toxoid (DT) by various adjuvants in transcutaneous immunization (TCI) with microneedle array pretreatment was investigated. METHODS: TCI was performed on BALB/c mice with or without microneedle array pretreatment using DT as a model antigen co-administrated with lipopolysaccharide (LPS), Quil A, CpG oligo deoxynucleotide (CpG) or cholera toxin (CT) as adjuvant. The immunogenicity was evaluated by measuring serum IgG subtype titers and neutralizing antibody titers. RESULTS: TCI with microneedle array pretreatment resulted in a 1,000-fold increase of DT-specific serum IgG levels as compared to TCI. The immune response was further improved by co-administration of adjuvants, showing a progressive increase in serum IgG titers when adjuvanted with LPS, Quil A, CpG and CT. IgG titers of the CT-adjuvanted group reached levels comparable to those obtained after DT-alum subcutaneous injection. The IgG1/IgG2a ratio of DT-specific antibodies decreased in the following sequence: plain DT, Quil A, CT and CpG, suggesting that the immune response was skewed towards the Th1 direction. CONCLUSIONS: The potency and the quality of the immune response against DT administered by microneedle array mediated TCI can be modulated by co-administration of adjuvants.
