LONDON—A leading coronavirus-vaccine candidate being developed by University of Oxford researchers and AstraZeneca PLC showed positive results in early trials, according to results published Monday, raising the prospect that a shot could be available by the end of this year.

A study of 1,077 healthy adults who received the vaccine showed it produced two kinds of immune response that could defend a body against Covid-19, according to results published in the Lancet, a British medical journal. The vaccine caused no serious side…

Read More