WASHINGTON More than eight years ago, the federal government invested in an insurance policy against vaccine shortages during a pandemic. It paid Emergent BioSolutions, a Maryland biotech firm known for producing anthrax vaccines, to have a factory in Baltimore always at the ready. When the coronavirus pandemic arrived, the factory became the main U.S. location for manufacturing COVID-19 vaccines developed by Johnson & Johnson and AstraZeneca, churning out about 150 million doses as of last week….
