EXHIBIT 99.1

AVANT Receives NASDAQ Deficiency Notice Relating to Minimum Bid Price

    NEEDHAM, Mass.--(BUSINESS WIRE)--July 10, 2007--AVANT
Immunotherapeutics (Nasdaq: AVAN) announced today that on July 6, 2007
it received a letter from The NASDAQ Stock Market stating that for the
last 30 consecutive business days, the closing bid price per share for
AVANT's common stock has been below the $1.00 minimum per share
requirement for continued inclusion under NASDAQ Marketplace Rule
4450(a)(5).

    In accordance with NASDAQ Marketplace Rule 4450(e)(2), AVANT has
180 calendar days, or until January 2, 2008, to regain compliance by
maintaining a closing bid price per share of $1.00 or higher for a
minimum of 10 consecutive business days. The NASDAQ Letter has no
effect on the listing of AVANT's common stock at this time. AVANT will
seek to regain compliance within this cure period and is considering
alternatives to address compliance with the continued listing
standards of The NASDAQ Stock Market. If AVANT does not demonstrate
compliance within the required period AVANT will be issued a delisting
letter, which may be appealed at that time. If AVANT is unsuccessful
in meeting the minimum bid requirement during an initial 180-day
compliance period, AVANT may apply to transfer the listing of its
common stock to The Nasdaq Capital Market and receive an additional
180-day compliance period, if AVANT meets all initial listing
criteria, except for the minimum bid requirement, for that market as
set forth in Marketplace Rule 4310(c).

    Additional information on AVANT Immunotherapeutics, Inc. can be
obtained through our site on the World Wide Web:
http://www.avantimmune.com.

    Safe Harbor Statement Under the Private Securities Litigation
Reform Act of 1995: This release includes forward-looking statements
that are subject to a variety of risks and uncertainties and reflect
AVANT's current views with respect to future events and financial
performance. There are a number of important factors that could cause
the actual results to differ materially from those expressed in any
forward-looking statement made by AVANT. These factors include, but
are not limited to: (1) the integration of multiple technologies and
programs; (2) the ability to adapt AVANT's vectoring systems to
develop new, safe and effective orally administered vaccines against
anthrax and plague or other any other microbes used as bioweapons and
other disease causing agents; (3) the ability to successfully complete
product research and further development, including animal,
pre-clinical and clinical studies, and commercialization of
CholeraGarde(R) (Peru-15), Ty800, ETEC E. coli vaccine, VLPs and other
products and AVANT's expectations regarding market growth; (4) the
cost, timing, scope and results of ongoing safety and efficacy trials
of CholeraGarde(R) (Peru-15), Ty800, ETEC E. coli vaccine and other
preclinical and clinical testing; (5) the ability to negotiate
strategic partnerships or other disposition transactions for AVANT's
cardiovascular programs, including TP10 and CETi; (6) the ability of
AVANT to manage multiple clinical trials for a variety of product
candidates; (7) AVANT's expectations regarding its technological
capabilities and expanding its focus to broader markets for vaccines;
(8) the Company's expectations regarding the cost of funding its
development partnership with Select Vaccines Limited for the influenza
vaccine, the opportunity to extend to other disease targets, and
AVANT's ability to develop products through this collaboration; (9)
changes in existing and potential relationships with corporate
collaborators; (10) the availability, cost, delivery and quality of
clinical and commercial grade materials produced at AVANT's own
Manufacturing facility or supplied by contract manufacturers and
partners; (11) the timing, cost and uncertainty of obtaining
regulatory approvals; (12) the ability to develop and commercialize
products before competitors that are superior to the alternatives
developed by competitors; (13) the ability to retain certain members
of management;(14) AVANT's expectations regarding research and
development expenses and general and administrative expenses; (15)
AVANT's expectations regarding cash balances, capital requirements,
anticipated royalty payments (including those from Paul Royalty Fund),
revenues and expenses, including infrastructure expenses; (16) our
belief regarding the validity of our patents and potential litigation;
and (17) certain other factors that might cause AVANT's actual results
to differ materially from those in the forward-looking statements
including those set forth under the headings "Business," "Risk
Factors" and Management's Discussion and Analysis of Financial
Condition and Results of Operations" in each of AVANT's Annual Report
on Form 10-K, its Quarterly Reports on Form 8-K, as well as those
described in AVANT's other press releases and filings with the
Securities and Exchange Commission, from time to time. You should
carefully review all of these factors, and you should be aware that
there may be other factors that could cause these differences. These
forward-looking statements were based on information, plans and
estimates at the date of this press release, and AVANT does not
promise to update any forward-looking statements to reflect changes in
underlying assumptions or factors, new information, future events or
other changes.

    CONTACT: AVANT Immunotherapeutics, Inc.
             Una S. Ryan, Ph.D., 781-433-0771
             President and CEO
             or
             Avery W. Catlin, 781-433-0771
             Chief Financial Officer
             info@avantimmune.com
             or
             For Media:
             Kureczka/Martin Associates
             Joan Kureczka, 415-821-2413
             jkureczka@comcast.net