VaxGen Issues Rebuttal to MedCap Letter(he ISS estimatedliquidation outcome is n...)

MedCap's selective use of these third party sources is especially disturbing because they are based on limited distribution reports, usually only available to professional investors. Hence, MedCap's selective use of such information could easily mislead many or most of VaxGen's stockholders who do not have access to the full text of those reports. The ISS recommendations and their rationale are discussed in the addendum to this letter.

VaxGen believes these recent communications from MedCap show a flagrant disregard for accuracy. We have reason to believe that MedCap has made even more inaccurate and misleading claims in its conversations with other stockholders and third parties. We can only conclude that MedCap cares not about the truth; but rather about defeating the proposed merger at any cost.

In summary, MedCap and its principals have apparently determined to sway the VaxGen-Raven merger vote any way they can. VaxGen believes this includes the use of flawed arguments as well as false and misleading information. As the CEO of VaxGen, I urge stockholders to examine the facts objectively. If you do so, I continue to believe the correct outcome is to vote "Yes" in favor of the merger.

Sincerely,

James P. Panek

President and CEO

VaxGen, Inc.

Detailed Discussion Regarding Financial and Liquidation Claims; ISS Recommendations

MedCap's Financial Analysis is both Incorrect and Shallow.

MedCap represents that VaxGen spent $56.1 million in 2007, or $40.1 million, before impairments or restructuring. In fact, neither of these figures (which are drawn from the profit and loss account) are accurate representations of the Company's cash burn in 2007. The best measure of this is to be found in the Consolidated Statements of Cash Flows on page 39 of the Company's 2007 Annual Report
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