LONDON – Scientists at Imperial College London will start immunizing people in Britain this week with their experimental coronavirus shot, becoming the latest entry into the race to find an effective vaccine to stop the pandemic.In a statement, the British government said 300 healthy people will be immunized with two doses of the COVID-19 vaccine candidate developed at Imperial, which has been backed by 41 million pounds ($51 million) in government funding.So far, the vaccine candidate developed by Imperial College London has only been tested in animals and in the laboratory, where it produced much higher levels of antibodies than would normally be seen in infected people.Many scientists have warned that the pandemic might only be stopped.