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                                                                      Exhibit 31

                         CERTIFICATION UNDER SECTION 302

I, Emile Loria, certify that:

1. I have reviewed this quarterly report on Form 10-Q of Epimmune Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a
material fact or omit to state a material fact necessary to make the statements
made, in light of the circumstances under which such statements were made, not
misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects the
financial condition, results of operations and cash flows of the registrant as
of, and for, the periods presented in this report;

4. The registrant's other certifying officers and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and we have:

      a) Designed such disclosure controls and procedures, or cause such
disclosure controls and procedures to be designed under our supervision, to
ensure that material information relating to the registrant, including its
consolidated subsidiaries, is made known to us by others within those entities,
particularly during the period in which this report is being prepared;

      b) Designed such internal control over financial reporting, or caused such
internal control over financial reporting to be designed under our supervision,
to provide reasonable assurance regarding the reliability of financial reporting
and the preparation of financial statements for external purposes in accordance
with generally accepted accounting principles;

      c) Evaluated the effectiveness of the registrant's disclosure controls and
procedures and presented in this report our conclusions about the effectiveness
of the disclosure controls and procedures as of the end of the period covered by
this report based on such evaluation; and

      d) Disclosed in this report any change in the registrant's internal
control over financial reporting that occurred during the registrant's most
recent fiscal quarter that has materially affected, or is reasonably likely to
materially affect, the registrant's internal control over financial reporting;
and

5. The registrant's other certifying officers and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
registrant's auditors and the audit committee of registrant's board of directors
(or persons performing the equivalent function):

      a) All significant deficiencies and material weaknesses in the design or
operation of internal control over financial reporting, which are reasonably
likely to adversely affect the registrant's ability to record, process,
summarize and report financial information; and

      b) Any fraud, whether or not material, that involves management or other
employees who have a significant role in the registrant's internal control over
financial reporting.

Date: August 14, 2003

                                                  /s/ Emile Loria
                                                  ------------------------------
                                                  Dr. Emile Loria
                                                  President and Chief Executive
                                                  Officer





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I, Robert J. De Vaere, certify that:

1. I have reviewed this quarterly report on Form 10-Q of Epimmune Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a
material fact or omit to state a material fact necessary to make the statements
made, in light of the circumstances under which such statements were made, not
misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects the
financial condition, results of operations and cash flows of the registrant as
of, and for, the periods presented in this report;

4. The registrant's other certifying officers and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and we have:

         a) Designed such disclosure controls and procedures, or cause such
disclosure controls and procedures to be designed under our supervision, to
ensure that material information relating to the registrant, including its
consolidated subsidiaries, is made known to us by others within those entities,
particularly during the period in which this report is being prepared;

         b) Designed such internal control over financial reporting, or caused
such internal control over financial reporting to be designed under our
supervision, to provide reasonable assurance regarding the reliability of
financial reporting and the preparation of financial statements for external
purposes in accordance with generally accepted accounting principles;

         c) Evaluated the effectiveness of the registrant's disclosure controls
and procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures as of the end of the
period covered by this report based on such evaluation; and

         d) Disclosed in this report any change in the registrant's internal
control over financial reporting that occurred during the registrant's most
recent fiscal quarter that has materially affected, or is reasonably likely to
materially affect, the registrant's internal control over financial reporting;
and

5. The registrant's other certifying officers and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
registrant's auditors and the audit committee of registrant's board of directors
(or persons performing the equivalent function):

         a) All significant deficiencies and material weaknesses in the design
or operation of internal control over financial reporting, which are reasonably
likely to adversely affect the registrant's ability to record, process,
summarize and report financial information; and

         b) Any fraud, whether or not material, that involves management or
other employees who have a significant role in the registrant's internal control
over financial reporting.

Date:    August 14, 2003

                                            /s/ Robert J. De Vaere
                                            ------------------------------------
                                            Robert J. De Vaere
                                            Vice President, Finance and
                                            Administration, and Chief Financial
                                            Officer