LOW-ADDITIVE INFLUENZA VACCINES

1 - 12 : (canceled)

13 : A sterile vaccine comprising an inactivated influenza virus antigen, wherein the vaccine contains no mercurial preservative, no antibiotic, no formaldehyde and no egg-derived materials.

14 : The vaccine of claim 13 , comprising less than 0.1 IU/ml of endotoxin.

15 : The vaccine of claim 13 , comprising less than 10 ng of host cell DNA per 15 mg of haemagglutinin.

16 : The vaccine of claim 13 , wherein the antigen is a split virus antigen.

17 : The vaccine of claim 13 , wherein, the antigen is a purified surface glycoprotein antigen.

18 : The vaccine of claim 13 , wherein the antigen is a virosome.

19 : The vaccine of claim 13 , comprising antigen from more than one influenza virus strain.

20 : The vaccine of claim 13 , further comprising an adjuvant.

21 : The vaccine of claim 20 , wherein the adjuvant is an oil-in-water emulsion.

22 : The vaccine of claim 21 , wherein the oil-in-water emulsion comprises squalene.

23 : A method of preparing a sterile influenza virus antigen formulation containing no mercurial preservative, no antibiotic, no formaldehyde and no egg-derived materials, comprising the steps of: (i) growing influenza virus in a cell culture system, in the absence of egg-derived materials and antibiotic; (ii) inactivating the influenza virus grown in step (i), in the absence of formaldehyde; and (iii) preparing a vaccine antigen formulation from the inactivated influenza virus, in the absence of thimerosal.

24 : The method of claim 23 , wherein the influenza virus in step (ii) is treated with an alkylating agent.

25 : The method of claim 24 , wherein the influenza virus is grown in MDCK cells.

26 : The method of claim 25 , wherein the MDCK cells come from the MDCK cell line 33016, deposited as DSM ACC2219.

27 : The method of claim 23 , wherein step (i) is performed in serum-free media.