preparation of chitosan (cs) microspheres as a novel drug delivery vehicle for intranasal immunization using high, medium and low cs molecular weight (mw) was investigated in this study. diphtheria toxoid (dt) was used as a model antigen. the emulsion-solidification method was adopted for microencapsulation of dt.  in the first step, following the purification of semi-crude dt by the ion-exchan...

The Lf-unit, which is used in the control of diphtheria and tetanus toxoid production and in some countries also to follow immunization of horses for production of antitoxins, has hitherto been defined by means of antitoxin preparations. A diphtheria toxoid and a tetanus toxoid preparation, both freeze-dried, were examined in an international collaborative study for their suitability to serve a...

The simultaneous administration of B.C.G. vaccine, diphtheria-tetanus toxoid aluminium hydroxide adsorbed vaccine, and oral poliovaccine was studied in 628 children aged 13-14 years between 1966 and 1969 in Newham, London. The efficacy of these vaccines was unaffected by administering them at the same time; routine simultaneous administration is considered justified when organizational difficul...

The most critical step in the production of diphtheria vaccines is the inactivation of the toxin by formaldehyde. Diphtheria toxoid (DTx) is produced during this inactivation process through partly unknown, chemical modifications of the toxin. Consequently, diphtheria vaccines are difficult to characterise completely and the quality of the toxoids is routinely determined with potency and safety...

BACKGROUND Recommendations for diphtheria immunization are to apply an effective primary immunization in infancy and to maintain immunity throughout life. Immunity against diphtheria depends primarily on antibody to the diphtheria toxin. This study evaluated the seroprevalence of IgG diphtheria antitoxin in sera of healthy children, adolescents and adults in Poland. METHODS A total of 1387 se...

Simultaneous transfer of delayed hypersensitivity to diphtheria toxin and to tuberculin has been accomplished in eight consecutive instances in man using extracts from washed leucocytes taken from the peripheral blood of tuberculin-positive, Schick-negative donors who were highly sensitive (i.e., pseudoreactors) to purified diphtheria toxin and toxoid. The leucocyte extracts used for transfer c...

In Hyderabad, India, diphtheria is common among children aged 5-19 years. On account of low coverage of diphtheria vaccine boosters recommended under the universal immunization programme, a large proportion of children were susceptible/partially immune against diphtheria and/or tetanus. We evaluated immunogenicity and safety of single dose of indigenously developed tetanus-diphtheria (Td) vacci...

The pediatric formulations usually have 3-5 times as much of the diphtheria component than what is in the adult/ adolescent formulation. Similarly, the formulations for adults/adolescents have around one third of acellular pertussis content than pediatric formulations. The amount of tetanus toxoid in each of the products remains almost equivalent. Dose reduction for diphtheria and pertussis is ...

Relevance. It is known that antitoxic immunity saves from diphtheria, but does not prevent the carriage of Cd (tox+). Asymptomatic carriers (tox+) play a major role in maintaining epidemiological process diphtheria infection. Aims. Characteristics population composition and specifics kinetic reactions (tox-) simultaneously functioning among people. Results. The functional features specific indi...