Researchers find vaccine roughly as effective against Brazilian variant as it was against other, les

Vaccine protects against illness and prevents infection

Some European governments have raised separate concerns about its effectiveness in older population

Some European governments have raised separate concerns about its effectiveness in older population

Researchers say that, based on their trial, which involved about 20,000 people in Russia last fall,

But chief scientist says countries must come to a consensus on which populations would be prioritize

Demand for hydroxychloroquine, a drug approved decades ago, surged after Trump touted its use as a c