said its vaccine appears nearly 95% effective. This comes on the heels of Pfizer's announcement that its shot appeared similarly effective.Those numbers raised hopes around the world that vaccines could help put an end to the pandemic sometime next year if they continue to show that they prevent disease and are safe.Effectiveness numbers will change as the vaccine studies continue since the early calculations were based on fewer than 100 COVID-19 cases in each study.
But early results provide strong signals that the vaccine could prevent a majority of disease when large groups of people are vaccinated.U.S.
health officials said a coronavirus vaccine would need to be at least 50% effective before they would consider approving it for use..