A plant in the US which ruined 15 million potential doses of Johnson and Johnson's Covid-19 vaccine has been asked to stop producing doses for AstraZeneca, the media reported.The facility at Baltimore, Emergent Biosolutions, was earlier picked as a manufacturing partner for both AstraZeneca and Johnson and Johnson.In a statement on Saturday, Johnson and Johnson said it was "assuming full responsibility" regarding the manufacturing of drug substance for its Covid-19 vaccine at the Emergent BioSolutions.The development, first reported by The New York Times, could be a setback for AstraZeneca which is yet to receive approval for its Covid-19 vaccines in the US.According to a report in The New York Times last week, a mix-up at the Baltimore manufacturing plant ruined 15 million potential doses of the Johnson and Johnson Covid-19 vaccine.Johnson and Johnson then said that the "quality control process identified one batch of drug substance that did not meet quality standards at Emergent Biosolutions, a site not yet authorised to manufacture drug substance for our Covid-19 vaccine".After taking charge of manufacturing its drug substance at the facility, the company said it was adding dedicated leaders for operations and quality, and significantly increasing the number of manufacturing, quality and technical operations personnel to work with the specialists already at Emergent.Johnson and Johnson said that all of its Covid-19 vaccine doses distributed to date have met rigorous regulatory quality standards.