Mail Stop 6010	January 4, 2006

Mr. Stanley C. Erck
Chief Executive Officer
Iomai Corporation
20 Firstfield Road, Suite 250
Gaithersburg, Maryland 20878

Re:	Iomai Corporation
      Amendment No. 3 to Registration Statement on Form S-1
Filed December 20, 2005
File No. 333-128765

Dear Mr. Erck:

      We have reviewed your filing and have the following
comments.
Where indicated, we think you should revise your document in
response
to these comments.  If you disagree, we will consider your
explanation as to why our comment is inapplicable or a revision is
unnecessary.  Please be as detailed as necessary in your
explanation.
In some of our comments, we may ask you to provide us with
supplemental information so we may better understand your
disclosure.
After reviewing this information, we may or may not raise
additional
comments.

      Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or on any other
aspect
of our review.  Feel free to call us at the telephone numbers
listed
at the end of this letter.

General

1. We note your response to our prior comment 2 and reissue that
comment in part.

* We note your statement that each of your product candidates,
consisting of a patch and one or more active ingredients, are
"treated as an investigational product candidate by the FDA," and
that none of your product candidates or any of the active
ingredients
"have been approved by the FDA for sale or commercial use."  On
page
2, however, you refer to use of the IS patch with "existing
commercially available injectable flu vaccine."  Please clarify
these
statements.

* With respect to your needle-free travelers` diarrhea patch,
please
revise your disclosure to clarify that you are developing the
vaccine
as well as the patch as a delivery system.

Index to Financial Statements, page F-1

Notes to Financial Statements, page F-8

4.  Elan Restructuring, page F-16

Restructuring Agreement, page F-18

2. Please elaborate on your response to prior comment eleven to
clarify how the fair value of the convertible notes contemplated
that
the restructuring was done in connection with the Series C
Preferred
Stock financing, which presumably would have provided you with an
alternative source to repay the convertible notes.  While your
asserted that you could not obtain an investment without
restructuring the joint venture and Elan`s interest in the
Company,
please clarify the extent to which the investment was contingent
upon
the Elan exchanging the convertible notes for shares of your
Series B
Preferred Stock.  In addition, please clarify how the fair value
is
appropriate when you apparently had to apply all of the following
to
the principal and accured interest due on the convertible notes:
(a)
a portion of the Series B Preferred Stock, (b) the Make-Whole
Amount,
and (c) a portion of the gross proceeds from the Series C
Preferred
Stock financing.


*	*	*	*	*


      As appropriate, please amend your filing in response to
these
comments.  You may wish to provide us with marked copies of the
amendment to expedite our review.  Please furnish a cover letter
with
your amendment that keys your responses to our comments and
provides
any requested supplemental information.  Detailed cover letters
greatly facilitate our review.  Please file your cover letter on
EDGAR under the form type label CORRESP. Please understand that we
may have additional comments after reviewing your amendment and
responses to our comments.

      We direct your attention to Rules 460 and 461 regarding
requesting acceleration of a registration statement.  Please allow
adequate time after the filing of any amendment for further review
before submitting a request for acceleration.  Please provide this
request at least two business days in advance of the requested
effective date.

      You may contact Tabatha Akins at (202) 551-3658 or Oscar
Young
at (202) 551-3622 if you have questions regarding comments on the
financial statements and related matters.  Please contact Sonia
Barros at (202) 551-3655 or Suzanne Hayes at (202) 551-3675 with
any
other questions.


								Sincerely,



								Jeffrey P. Riedler
								Assistant Director

cc:	Paul M. Kinsella, Esq.
Ropes & Gray LLP
One International Place
Boston, MA 02110-2624

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Mr. Stanley C. Erck
January 4, 2006
Page 1