Abstract A method has been found, which makes it possible to prepare a composition containing one or more vaccines adsorbed on an appropriate substrate. The method comprises introducing one or several antigens into an aqueous solution of dibasic sodium phosphate having preferably a concentration of 0.01 M to 0.5 M, adding to the mixture thus formed an amount of calcium chloride in aqueous solution, preferably substantially equivalent to that of the phosphate, and adjusting the pH of the mixture to a value close to 7, preferably about 6.8 to 7. A precipitate forms, which adsorbs the antigens, and it is recovered. The best concentration of the calcium chloride solution is in the range of 0.01 M to 0.5 M.
Method according to claim 1, wherein the dibasic sodium phosphate solution and the calcium chloride solution have substantially similar molar concentrations of 0.01 to 0.5 M.
Claim 2
Dependent Claim
25 words
Process in accordance with claim 2, characterized in that the amount of calcium chloride added is of 1 mole per mole of dibasic sodium phosphate.
Claim 3
Dependent Claim
24 words
Process in accordance with claim 1, characterized in that the pH of the mixture is adjusted to a value of about 6.8 to 7.
Claim 4
Dependent Claim
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Process in accordance with claim 1, in which the antigen is taken in the concentrated state.
Claim 5
Dependent Claim
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Process in accordance with claim 5, in which the antigen is introduced into the dibasic sodium phosphate solution by dialysis.
Claim 6
Dependent Claim
18 words
Process in accordance with claim 1 in which the antigen is made of a substance secreted by micro-organisms.