Johnson & Johnson is assuming full responsibility on the manufacturing of a drug substance for its Covid-19 vaccine at Emergent BioSolutions Inc.’s Bayview facility, the company said in a statement.It will add dedicated leaders for operations and quality, and “significantly" increase the number of manufacturing, quality and technical operations personnel at the site, according to the statement.The company will work closely with the Food and Drug Administration for the emergency use authorization of the specific facility, adding that all its doses so far have met regulatory quality standards.