Ann: Half Year Report and Accounts, page-17

Remember BARDA's purpose is to facilitate Mass Casualty Preparedness, much of the 50 plus million is about relieving the drain on cash flows, to ensure disaster readiness. I suspect you need not worry about the cashflow inherent in your question.
The current annualised runrate for cashflow support is possibly $5m ie ~600k for 3 months, October to December, and this would likely be before too much MCP inventory buildup and the commencement of training staff and surgeons at the 50plus specialised Burns Centres across the US, given the short time frame the BARDA contract has been on foot.