Photo taken on July 21, 2020 shows a sign in the 125 London Wall building, where medical journal The Lancet's London office is based, in London, Britain. A phase 2 trial of a COVID-19 vaccine candidate conducted in China has found that the vaccine is safe and induces an immune response, according to a new study published on Monday in medical journal The Lancet. (Photo by Tim Ireland/Xinhua)
