INTRANASAL BOOSTER VACCINATION AGAINST DIPHTHERIA AND TETANUS IN MAN

The booster responses of three different formulations of intranasal (i .n.) diphtheria-tetanus (D-T) vaccines were determined in military rec ruits and compared with a conventional subcutaneous D-T vaccine. The v accines for mucosal delivery were sprayed into one nostril and contain ed D and T toxoids in an enhancer mixture of polysorbate and caprylic/ capric glycerides. All of the vaccines gave rise mainly to a systemic IgG response. Among 51 persons with anti-D antibody concentrations in serum below a protective level of 0.01 international units (IU mi befo re vaccination, all except two attained protective antibody concentrat ions 4 weeks after vaccination The median increase in anti-D antibody concentration Mins 113-fold with the most efficient in. formulation. T he median increase in anti-T antibody level was 2.4-fold, however, the pre-vaccination levels for this antigen were very high. Within the ex amined levels, the booster response depended mainly on the dose of the antigen in the vaccine rather than on the concentration of the vehicl e mixture. Compared with the parenteral D-T vaccine containing alumini um hydro,vide as an adjuvant, all of the rested in. formulations showe d somewhat lower immunogenicity in man as well as in pre-clinical guin ea-pig studies. Among 215 persons immunized i.n., 61% preferred this r oute of administration rather than a parenteral injection, although th e formulations were all associated with varying local symptoms,frequen tly stinging and pronounced, nasal secretion. (C) 1997 Elsevier Scienc e Ltd.