Medicago USA has received a third milestone payment from the Defense Advanced Research Projects Agency toward completion of the vaccine plant it is building in RTP.

The $5.6 million brings to $16.3 million the total Medicago has received from DARPA.

A fourth payment is still due as part of the $21 million contract.

Medicao is focused on vaccines utilizing virus-like particles, or VLPs.

“We continue to meet all milestones to date for this fast track project and our U.S. vaccine facility is projected to be operational during the second half of 2011,” said Mike Wanner, vice president of operations for the company, in a statement.

The plant covers 90,000 square feet.

“Medicago intends to demonstrate its capacity to produce 10 million doses/month of influenza vaccines with the potential for further expansion in the future,” the company said.

The facility is part of efforts by DARPA to find new ways of producing large amounts of vaccine in the event of a biologic threat.

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