Abstract: A process for producing a split influenza virus preparation or subunit influenza preparation comprising the steps of: (i) providing a whole virus preparation; (ii) splitting the whole virus preparation in the presence of a first detergent; (iii) adding t-octylphenoxypolyethoxyethanol (TRITON X-100™) to the resulting split virus preparation; and (iv) filtering the split virus preparation.

Abstract: A process for producing a split influenza virus preparation or subunit influenza preparation comprising the steps of: (i) providing a whole virus preparation; (ii) splitting the whole virus preparation in the presence of a first detergent; (iii) adding t-octylphenoxypolyethoxyethanol (TRITON X-100™) to the resulting split virus preparation; and (iv) filtering the split virus preparation.

Abstract: A process for producing a split influenza virus preparation or subunit influenza preparation comprising the steps of: (i) providing a whole virus preparation; (ii) splitting the whole virus preparation in the presence of a first detergent; (iii) adding t-octylphenoxypolyethoxyethanol (TRITON X-100™) to the resulting split virus preparation; and (iv) filtering the split virus preparation.

Abstract: An inactivated influenza virus preparation is described which comprises a haemagglutinin antigen stabilized in the absence of thiomersal, or at low levels of thiomersal, wherein the haemagglutinin is detectable by a SRD assay. The influenza virus preparation may comprise a micelle modifying excipient, for example ?-tocopherol or a derivative thereof in a sufficient amount to stabilize the haemagglutinin.

Abstract: A compound of formula (I) or a pharmaceutically acceptable salt thereof: ##STR1## wherein: R.sub.1 is --CH.sub.3 or --CH.sub.2 CH.sub.3 unsubstituted or substituted by 1 to 3 fluorines;X is O or S(O).sub.s where s=0 to 2;R.sub.2 is C.sub.4 -C.sub.6 cyclic alkyl, optionally substituted by one to three methyl groups or one ethyl group; --CH.sub.2 -cyclopentyl, --CH.sub.2 -cyclopropyl, 3-tetrahydrofuranyl, C.sub.1-7 alkyl, CH.sub.3 or CH.sub.2 CH.sub.3 substituted by one to three fluorines;--(CH.sub.2).sub.n COO(CH.sub.2).sub.g CH.sub.3, or (CH.sub.2).sub.n O(CH.sub.2).sub.g CH.sub.3, wherein n is 2 to 4 and g is 0 to 2;R.sub.3 represents a moiety of formula (a); ##STR2## wherein R.sub.4 and R.sub.5 each represent hydrogen or R.sub.4 and R.sub.5 together represent a bond;B represents >C.dbd.O, >C.dbd.S or >CH--R.sub.6 wherein R.sub.6 represents H, OH, C.sub.1-6 alkoxy or C.sub.