Method for Preserving Alum Adjuvants and Alum-Adjuvanted Vaccines

A method for preserving an aluminium-salt adjuvant during freezing or drying comprising freezing or drying an aqueous suspension or solution comprising:

• (a) an aluminium salt adjuvant;
• (b) a compound of formula (I) or a physiologically acceptable salt or ester thereof
• wherein:
• R1 represents hydrogen or C1-6 alkyl;
• and
• R4 represents hydrogen;
• or
• R1 and R4 together with the atoms to which they are attached form a pyrrolidine ring;
• R2 represents hydrogen, C1-6 alkyl or —(CH2)2-5NHC(O)(CH2)5-15CH3;
• and
• R3 represents C1-6 alkyl;
• or
• a compound of formula (II) or a physiologically acceptable salt or ester thereof
• wherein:
• X represents —S(O)2— or —S+(Rc)—
• Ra and Rb independently represent C1-6 alkyl;
• and
• Rc represents C1-6 alkyl substituted with a carboxylate anion and with an amine (—NH2) moiety;
• and
• (c) one or more sugars.