A vaccine composition comprising two valences is provided: (i) a first
valence which is adjuvant-enhanced with aluminum hydroxide and (ii) a
second valence which contains a polysaccharide of bacterial capsule
comprising one or more o-acetyl groups and which is not adsorbed with
aluminum oxide due to the presence of a protecting compound which may be
a phosphate, a citrate or a carbonate and which prevents the adsorption.
The first valence can be any vaccine valence. In one particular
embodiment, the vaccine composition contains (i) Hepatitis A valence,
adsorbed on aluminum hydroxide and (ii) the typhoid fever valence formed
by the polysaccharide Vi of the Salmonella typhi capsule.