Nov 5 (Reuters) - The U.S. Food and Drug Administration said on Friday it had authorized the use of two more batches of Johnson & Johnson"s (JNJ.N) one-dose COVID-19 vaccine manufactured at the problem-plagued Baltimore factory of Emergent BioSolutions Inc (EBS.N). The FDA has now authorized 11 batches of the vaccine manufactured at the facility. In April, U.S. authorities halted production after ingredients from AstraZeneca"s (AZN.L) COVID-19 vaccine, also being produced at the plant at the time, contaminated a batch of J&J"s vaccine. Today"s authorization was based on a thorough review of facility records and quality testing by the manufacturer, and considering the current COVID-19 public health emergency, the health agency said in a statement.An estimated 30 million to 50 million doses of Johnson & Johnson"s COVID-19 vaccine made early this year have been sitting idle in the Baltimore plant for weeks awaiting a green light from U.S. regulators to ship, two sources familiar with the matter told Reuters late last month.