The New York Times is reporting that two potential vaccines against the virus from Oxford University and the Chinese company CanSino have triggered immune responses in hundreds of humans without dangerous side effects. The news was published on Monday in the British medical journal, The Lancet.
The results are the most promising indication yet of progress toward a vaccine that could end the pandemic.
A third potential vaccine, from the American biotechnology company Moderna, has also elicited immune responses in 45 people who have received it, according to a study released last week.
All three potential vaccines are now moving into larger tests, known as Phase III trials, aiming to show their effectiveness at preventing the diseases.
The Oxford vaccine, which is being produced in partnership with the British-Swiss drug giant AstraZeneca, is already in large Phase III tests in Britain, Brazil and South Africa. Another Phase III test involving 30,000 participants in the United States is set to begin next week, along with a parallel test of the Moderna vaccine. The CanSino vaccine has also passed safety tests and is heading for an efficacy trial in Brazil.
“Seeing these responses means that people should be optimistic that this vaccine will be useful,” said Prof. Adrian Hill of Oxford, one of the scientists developing the vaccine. “But there is no guarantee until you have shown efficacy in humans because you can’t know what you don’t know.”