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Astra Shot That Works Better in Small Doses Raises Questions

  • Initial half-dose was far more effective than full regimen
  • Astra may add new arm to U.S. trial for further study
Bloomberg business news
WHO Welcomes AstraZeneca Vaccine Results, Officials Say
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The news reached Sarah Gilbert Saturday evening that the Covid-19 vaccine she’s developed with AstraZeneca Plc appeared to work. But the University of Oxford professor had expected a key number: Was it more than 90% effective, as others have been -- or less?

Instead, when her colleague Andrew Pollard called with the results, he wanted to show her slides rather than simple figures. “I didn’t really understand why we would have to go through slides,” she recalled. “But then it became clear -- because it’s rather more complicated in our trial.”