[LETTERHEAD]

August 1, 1996

VIA EDGAR

Securities and Exchange Commission
450 Fifth Street, N.W.
Judiciary Plaza
Washington, D.C. 20549
Attn: Kim Do, Esq. and Sarah Cunningham, Esq.

Re:   AVIRON
      REGISTRATION STATEMENT
      ON FORM 8-A (FILE NO. 0-20815)

Ladies and Gentlemen:

On behalf of Aviron (the "Registrant"), we hereby request that the 
Registrant's Registration Statement on Form 8-A, File No. 0-20815 
(the "Form 8-A"), filed with the Commission on June 5, 1996, as amended July 
16, 1996, be withdrawn. Due to market conditions, the Registrant has 
previously withdrawn its request that its Registration Statement on Form S-1, 
File No. 333-05209 (the "Form S-1"), be declared effective. We are requesting 
withdrawal of the Form 8-A so that the Form 8-A does not become effective 
prior to the effectiveness of the Form S-1. The Registrant intends to refile 
the Form 8-A at such time as the Registrant may determine to go forward with 
the Form S-1.

If you have any comments or questions concerning this request, please call me 
at (415) 843-5013 or, in my absence, Robert J. Brigham at (415) 843-5053.

Very truly yours,

COOLEY GODWARD CASTRO
HUDDLESON & TATUM

/s/ Linda M. DeMelis

Linda M. DeMelis

cc:   J. Leighton Read, M.D.
      Alan C. Mendelson, Esq.
      Robert J. Brigham, Esq.
      Elizabeth Kurr, Esq.