Abstract: This invention relates to a process for preparing vaccines, which consists in bringing into contact a toxic product with glutaraldehyde at a concentration and for a duration just sufficient to detoxify or inactivate said toxic product, and in stopping the glutaraldehyde-antigen reaction as soon as said inactivation stage is reached by physical and/or chemical means. The thus obtained inactivate product remaining antigenic and retaining its immunizing power, is usable as a vaccine for the preventive treatment of human and animals against infections caused for example by microbial or venomous toxins.

Abstract: This invention relates to a process for preparing vaccines, which consists in bringing into contact a toxic product with glutaraldehyde at a concentration and for a duration just sufficient to detoxify or inactivate said toxic product, and in stopping the glutaraldehyde-antigen reaction as soon as said inactivation stage is reached by physical and/or chemical means. The thus obtained inactivate product remaining antigenic and retaining its immunizing power, is usable as a vaccine for the preventive treatment of human and animals against infection caused for example by microbial or venomous toxins.

Abstract: An improved aqueous gel of calcium phosphate, useful for preparation of adsorbed vaccines, prepared by contacting an antigen with an aqueous gel obtained by reacting an aqueous solution of dibasic sodium phosphate with an aqueous solution of calcium chloride, wherein the calcium chloride solution is poured as rapidly as possible, within less than 3 minutes, into said phosphate solution, in a proportion substantially equal to 1 mol PO.sub.4 HNa.sub.2 for 1 mol CaCl.sub.2, under stirring; the mixture thus obtained is still stirred while its pH is adjusted to a value very near 7, and the gel formed is subsequently decanted and washed. The gel is composed of calcium and phosphate ions in proportions such that the ratio Ca/P is 1.62 to 1.85, and exhibits a settling rate of 1 to 20 mm in 10 minutes at 20.degree. C when containing 0.07 atoms Ca per liter.

Abstract: This invention relates to a process for preparing vaccines, which consists in bringing into contact a toxic product with glutaraldehyde at a concentration and for a duration just sufficient to detoxify or inactivate said toxic product, and in stopping the glutaraldehyde-antigen reaction as soon as said inactivation stage is reached by physical and/or chemical means. The thus obtained inactivate product remaining antigenic and retaining its immunizing power, is usable as a vaccine for the preventive treatment of human and animals against infections caused for example by microbial or venomous toxins.