Potency Control of Diphtheria Component in Adsorbed Vaccines by In Vitro Neutralization Tests

Marcovistz, Rugimar; Matos, Denise C. S.; Georgini, Ricardo Amaral; Sakauchi, Dirce

doi:10.1006/biol.2002.0319

Cited by 8 publications

(7 citation statements)

References 10 publications

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“…In vitro tests for measuring tetanus and diphtheria antitoxin levels in serum were carried out by a standardized modified toxin-binding inhibition (TOBI) test as described by Hendriksen et al (13) but employing diphtheria toxoid instead of toxin (19,31,32).…”

Section: Methodsmentioning

confidence: 99%

Impaired Humoral Response to Vaccines among HIV-Exposed Uninfected Infants

Abramczuk

Mazzola

Moreno

et al. 2011

Clin. Vaccine Immunol.

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Little is known about the vaccine protective response for infants born from HIV-infected mothers. We evaluated the antibody response to hepatitis B, tetanus, and diphtheria vaccine in vertically HIV-exposed uninfected infants and compared them to those of control infants not exposed to the virus. The quantitative determination of specific neutralizing antibodies against hepatitis B, diphtheria, and tetanus were performed blindly on serum samples. The results showed that 6.7% of the HIV-exposed uninfected individuals were nonresponders to hepatitis B vaccine (anti-HBs titer, <10 mIU/ml), and 64.4% were very good responders (anti-HBs titer, >1,000 mIU/ml), whereas only 3.6% of the nonexposed infants were nonresponders ( 2 ‫؍‬ 10.93; 1 df). The HIV-exposed uninfected infants showed protective titers for diphtheria and tetanus but lower geometric mean anti-tetanus titers compared to those of the HIV-unexposed infants. Our data point to the necessity of evaluating vaccine immune responses in these children and reinforced that alterations in lymphocyte numbers and functions reported for newborns from HIV-infected mothers interfere with the vaccine response.

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Section: Methodsmentioning

confidence: 99%

Impaired Humoral Response to Vaccines among HIV-Exposed Uninfected Infants

Abramczuk

Mazzola

Moreno

et al. 2011

Clin. Vaccine Immunol.

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“…The ToBI test has been successfully used to determine diphtheria antitoxin in human and animal sera (Hendriksen et al 1989b, Hong & Hendriks 1999, Marcovistz et al 2002.…”

Section: Discussionmentioning

confidence: 99%

Immunogenicity test of tetanus component in adsorbed vaccines by toxin binding inhibition test

Matos

Marcovistz

Cabello

et al. 2002

Mem. Inst. Oswaldo Cruz

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“…(Toxin Binding Inhibition assay) (Souza Matos et al, 2002;Marcovistz et al, 2002). The toxin binding inhibition assay is composed of two parts: (a) serum neutralization followed by (b) ELISA.…”

Section: Effect Of Ph On Dtxd Conformation and Hydrophobicitymentioning

confidence: 99%

“…All the plate washings were done with 0.05% Tween 80 in PBS. Antibody titters (IU/mL) are the reciprocal serum dilution factor giving an absorbance value of 50% of the saturation value of the positive control (well containing the standard serum with known titer) (Souza Matos et al, 2002;Marcovistz et al, 2002).…”

Section: Effect Of Ph On Dtxd Conformation and Hydrophobicitymentioning

confidence: 99%

Enhanced Liposomal Vaccine Formulation and Performance: Simple Physicochemical and Immunological Approaches

Silva¹,

Takata

Sant’Anna

et al. 2006

Journal of Liposome Research

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The Dtxd (Diphtheria toxoid) was the first antigen encapsulated within liposomes, their adjuvant properties were discovered (their capacity to enhance the vaccine immunogenicity). The point here is not to propose a new method to prepare this lipossomal vaccine. The central idea is to give new dresses for old vaccines by using classical and well-established liposome preparation method changing only the encapsulation pH and the immunization protocol. The most appropriate method of Dtxd encapsulation within liposome was based on lipid film hydration in 100 mM citrate buffer, pH 4.0. This was accompanied by changes on protein hydrophobicity, observed by CD and fluorescence spectroscopies. Whenever the Dtxd exposed its hydrophobic residues at pH 4.0, it interacted better with the lipossomal (observed by electrophoretic mobility) film than when its hydrophobic residues were buried (pH 9.0). The Dtxd partition coefficient in Triton-X114 and the acrylamide fluorescence quenching were also pH dependent. Both were bigger at pH 4.0 than at pH 9.0. The relationship protein structure and lipid interaction was pH dependent and now it can be easily maximized to enhance encapsulation of antigens in vaccine development. Mice were primed with formulations containing 5 mug of Dtxd within liposomes prepared in pH 4.0 or 7.0 or 9.0. The boosters were done 38 or 138 days after the first immunization. The IgM produced by immediate response of all lipossomal formulations were higher than the control (free protein). The response patterns and the immune maturity were measured by IgG1 and IgG2a titrations. The IgG1 titers produced by both formulations at pH 4.0 and 7.0 were at least 22 higher than those produced by mice injected lipossomal formulation at pH 9.0. When the boosters were done, 138 days after priming the mice produced a IgG2a titer of 29 and the group that received the booster 30 days after priming produced a titer of 25. The strongest antibody production was the neutralizing antibody (245 higher than the control) produced by those mice injected with lipossomal formulation at pH 4.0 with the booster done 138 days after priming. The simple change on lipossomal pH formulation and timing of the booster enhanced both antibody production and selectivity.

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Potency Control of Diphtheria Component in Adsorbed Vaccines by In Vitro Neutralization Tests

Cited by 8 publications

References 10 publications

Impaired Humoral Response to Vaccines among HIV-Exposed Uninfected Infants

Impaired Humoral Response to Vaccines among HIV-Exposed Uninfected Infants

Immunogenicity test of tetanus component in adsorbed vaccines by toxin binding inhibition test

Enhanced Liposomal Vaccine Formulation and Performance: Simple Physicochemical and Immunological Approaches

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