Washington: A second clinical trial testing a Canadian-made vaccine against Ebola in humans began on today at the US National Institutes of Health (NIH), officials said.

Known as VSV-ZEBOV, the experimental vaccine was developed by researchers at the Public Health Agency of Canada's National Microbiology Laboratory, and is licensed to NewLink Genetics Corp in the US state of Iowa. The latest trial involves trying two doses, a strategy known as prime-boost, on 39 healthy adults to see if it generates a response from their immune systems, the NIH said in a statement.