<PAGE> 1
Filed Pursuant to
Rule 424(b)(3) and (c)
File No. 333-50505
PROSPECTUS SUPPLEMENT NO. 4 DATED JULY 7, 1998
TO PROSPECTUS DATED MAY 4, 1998
AVIRON
$100,000,000
5-3/4% Convertible Subordinated Notes due 2005
and
Shares of Common Stock Issuable Upon Conversion thereof
This Prospectus Supplement should be read in conjunction with the
Prospectus dated May 4, 1998 (the "Prospectus"). The table on pages 45 and 46 of
the Prospectus setting forth information concerning the Selling Securityholders
is superseded by the following table:
SELLING SECURITYHOLDERS
The following table sets forth the names of the Selling Securityholders,
the number of shares of Common Stock owned by each of them as of the date of
this supplement and the principal amount of Notes and number of Conversion
Shares which may be offered pursuant to this Prospectus. The information is
based upon information provided by or on behalf of the Selling Securityholders.
The Selling Securityholders may offer all, some or none of their Notes or
Conversion Shares.
<TABLE>
<CAPTION>
PRINCIPAL AMOUNT
OF NOTES OWNED PRINCIPAL AMOUNT COMMON STOCK OWNED
PRIOR TO OF NOTES OFFERED PRIOR TO COMMON STOCK
NAME OFFERING(1) HEREBY OFFERING(1)(2) OFFERED HEREBY
---- ----------- ------ -------------- --------------
<S> <C> <C> <C> <C>
AAM/Zazove Institutional Income $ 800,000 $ 800,000 0 0
Fund, L.P.
Alexandra Global Investment Fund I, 2,000,000 2,000,000 70,716 0
Inc.
Argent Classic Convertible 1,000,000 1,000,000 0 0
Arbitrage Fund L.P.
Argent Classic Convertible 2,000,000 2,000,000 0 0
Arbitrage Fund (Bermuda) L.P.
BancAmerica Robertson Stephens 1,250,000 1,250,000 0 0
BNP Arbitrage SNC 2,550,000 2,550,000 0 0
BT Holdings (New York), Inc. 1,000,000 1,000,000 0 0
Chrysler Corporation Master 2,330,000 2,330,000 0 0
Retirement Trust
CIBC Oppenheimer 0 0 0 0
</TABLE>
1.
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<TABLE>
<CAPTION>
PRINCIPAL AMOUNT
OF NOTES OWNED PRINCIPAL AMOUNT COMMON STOCK OWNED
PRIOR TO OF NOTES OFFERED PRIOR TO COMMON STOCK
NAME OFFERING(1) HEREBY OFFERING(1)(2) OFFERED HEREBY
---- ----------- ------ -------------- --------------
<S> <C> <C> <C> <C>
Declaration of Trust for the 100,000 100,000 0 0
Defined Benefit Plans of ICI
American Holdings Inc.
Declaration of Trust for the 65,000 65,000 0 0
Defined Benefit Plans of ZENECA
Holdings Inc.
Delaware PERS 720,000 720,000 0 0
Delaware State Employees' 335,000 335,000 0 0
Retirement Fund
Donaldson, Lufkin & Jenrette 1,000,000 1,000,000 0 0
Securities Corporation
Fidelity American Trust 200,000 200,000 0 0
Fidelity Financial Trust Fidelity 11,800,000 11,800,000 0 0
Convertible Securities Fund
Forest Alternative Strategies Fund 60,000 60,000 0 0
II Series A-5I
Forest Alternative Strategies Fund 1,175,000 1,175,000 0 0
II LP Series A-5
Forest Alternative Strategies Fund 30,000 30,000 0 0
II LP Series A-5M
Forest Alternative Strategies Fund 135,000 135,000 0 0
Series B-3
Forest Global Convertible Fund 1,175,000 1,175,000 0 0
Series A-5
Forest Global Convertible Fund 100,000 100,000 0 0
Series B-1
Forest Global Convertible Fund 75,000 75,000 0 0
Series B-2
Forest Global Convertible Fund 50,000 50,000 0 0
Series B-3
Forest Global Convertible Fund 75,000 75,000 0 0
Series B-5
Forest Greyhound 100,000 100,000 0 0
Forum Capital Markets L.P. 1,000,000 1,000,000 0 0
Fox Family Foundation 10/10/87 55,000 55,000 0 0
Fox Family Portfolio Partnership 200,000 200,000 0 0
Forest Performance Fund 75,000 75,000 0 0
</TABLE>
2.
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<TABLE>
<CAPTION>
PRINCIPAL AMOUNT
OF NOTES OWNED PRINCIPAL AMOUNT COMMON STOCK OWNED
PRIOR TO OF NOTES OFFERED PRIOR TO COMMON STOCK
NAME OFFERING(1) HEREBY OFFERING(1)(2) OFFERED HEREBY
---- ----------- ------ -------------- --------------
<S> <C> <C> <C> <C>
Heritage Series Trust Small Cap 1,000,000 1,000,000 100,000 0
Stock Fund
ICI American Holdings 310,000 310,000 0 0
JMG Convertible Investments, L.P. 500,000 500,000 0 0
LDG Limited 550,000 550,000 0 0
Lincoln National Convertible 1,700,000 1,700,000 0 0
Securities Fund
LLT Limited 45,000 45,000 0 0
MainStay Convertible Fund 2,000,000 2,000,000 68,800 0
McMahan Securities Company L.P. 1,050,000 1,050,000 0 0
Nalco Chemical Company 160,000 160,000 0 0
Northwestern Mutual Life Insurance 0 0 0 0
Company
OCM Convertible Limited Partnership 135,000 135,000 0 0
OCM Convertible Trust 3,225,000 3,225,000 0 0
Pacific Life Insurance Company 3,000,000 3,000,000 0 0
Paloma Securities L.L.C. 2,700,000 2,700,000 0 0
Partner Reinsurance Company, Ltd. 335,000 335,000 0 0
Schroders & Co. Inc. 1,000,000 1,000,000 0 0
Silverton International Fund Limited 2,300,000 2,300,000 0 0
Societe Generale Securities Corp. 6,500,000 6,500,000 0 0
State Employees' Retirement Fund of 725,000 725,000 0 0
the State of Delaware
State of Connecticut Combined 2,760,000 2,760,000 0 0
Investment Funds
Thermo Eletron Balanced Investment 0 0 0 0
Fund
TQA Leverage Fund, L.P. 1,100,000 1,100,000 0 0
TQA Vantage Fund, LTD 2,300,000 2,300,000 0 0
TQA Vantage Plus, LTD 750,000 750,000 0 0
Triton Capital Investments, Ltd. 500,000 500,000 0 0
</TABLE>
3.
<PAGE> 4
<TABLE>
<CAPTION>
PRINCIPAL AMOUNT
OF NOTES OWNED PRINCIPAL AMOUNT COMMON STOCK OWNED
PRIOR TO OF NOTES OFFERED PRIOR TO COMMON STOCK
NAME OFFERING(1) HEREBY OFFERING(1)(2) OFFERED HEREBY
---- ----------- ------ -------------- --------------
<S> <C> <C> <C> <C>
Vanguard Convertible Securities 1,990,000 1,990,000 0 0
Fund, Inc.
Walker Art Center 220,000 220,000 0 0
Weirton Trust 580,000 580,000 0 0
Zeneca Holdings Trust 310,000 310,000 0 0
----------- ----------- ----------- -----------
TOTAL $69,200,000 $69,200,000 239,516 0
=========== =========== =========== ===========
</TABLE>
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(1) Beneficial ownership is determined in accordance with the Rule of the
SEC and generally includes voting or investment power with respect to
securities. Except as otherwise indicated by footnote, and subject to
community property laws where applicable, the persons named in the table
have sole voting and investment power with respect to all shares on
Common Stock shown as beneficially owned by them. Numbers reflect
ownership prior to the date of this Supplement.
(2) Includes Conversion Shares based on a conversion price of $30.904 per
share and a cash payment in lieu of any fractional interest.
Because the Selling Securityholders may offer all or some of the Notes
that they hold and/or Conversion Shares pursuant to the offering
contemplated by this Prospectus, and because there are currently no
agreements, arrangements or understandings with respect to the sale of
any of the Notes or Conversion Shares by the Selling Securityholders, no
estimate can be given as to the principal amount of Notes or Conversion
of Shares that will be held by the Selling Securityholders after
completion of this offering.
4.
