<p style="text-align:start;" size="0" _root="undefined" __ownerid="undefined" __hash="undefined" __altered="false"><span style="color:#000000">The U.S. government has signed a deal to purchase 10 million courses of Pfizer’s antiviral Covid-19 pill, the company announced Thursday, the latest in a string of purchases as officials secure limited supplies of new coronavirus treatments. </span></p><p style="text-align:start;text-indent:2em;"></p>
