Exhibit 10.3

September 20, 2004

Jill Church

227 Muirfield Way

San Marcos, CA 92069

Dear Jill:

On behalf of Vijay Samant, I am pleased to confirm our offer of full-time employment with Vical. We hope that you will join us in this rewarding endeavor.

As we discussed, the basic components of the position and compensation will be as follows:

Additionally, you will receive stock options exercisable for 60,000 shares of Vical common stock. These options will be granted by the Stock Plan Committee of the Board and will reflect the fair market value of the stock on the date you begin as a Vical employee. The specific terms and conditions of these options are governed by both the Stock Incentive Plan of Vical Incorporated and the Option Agreement between you and the company. These will be provided to you upon execution of the required documents.

You will also be considered for a cash bonus award targeted at 0 - 25% of the base salary paid to you during 2005. Bonuses are proposed in February of each year and, if approved by the Vical Board of Directors, are paid out in March.

The enclosed benefit summary describes the benefits Vical currently offers to its employees. The effective date of group medical/dental coverage is the first of the month following your date of hire.

Jill, this offer is also contingent upon (1) the execution of the Company’s standard form of Employee Proprietary Information and Inventions Agreement (see attachment), and (2) satisfying the requirements of the Immigration Control and Reform Act. The latter issue can be accomplished by presenting a document or documents that establish identity and eligibility for employment within three days of commencing employment. A copy of the INS (Employment Eligibility Verification) form is attached. If you have any questions with regard to documents appropriate for these purposes, please contact me directly.

This offer is also contingent upon a background check and drug screen. A positive test will result in resention of the offer. Please contact HR at 858-646-1142 to set up the process.

Jill Church

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Your employment with Vical is “at-will”. In other words, either you or Vical can terminate your employment at any time for any reason, with or without cause and with or without notice. Except as described in the attachment titled “Salary Continuation,” upon termination of your employment you will only be entitled to the compensation and benefits described previously in this letter for the period preceding the effective date of the termination.

Please note that this offer supersedes any prior agreements, representations or promises of any kind, whether written, oral, express or implied, between the parties hereto with respect to the subject matters herein. It constitutes the full, complete and exclusive agreement between you and Vical with respect to the subject matters herein.

We hope you will decide to join us. We look forward to hearing positively from you.

Sincerely,

Vicki Hewlett

Director Human Resources

Upon acceptance of this offer, please sign one copy of this letter and one copy of the Employee Proprietary Information and Inventions Agreement and return them to Vicki Hewlett at Vical.

This offer of employment is accepted and agreed to:

Jill Church

Attachment

Salary Continuation

Subject to mitigation, Vical will continue to pay your base compensation, at the rate then in effect, for up to six months following the termination of your employment if, prior to the fourth annual anniversary of the commencement of your employment:

The salary continuation payments will cease in the event of your death. In order to receive your salary continuation, you will be required to sign a release in a form acceptable to Vical, of any and all claims that you may have against Vical.

Definitions: