UPDATE 4-U.S. secures 300 million doses of potential AstraZeneca COVID-19 vaccine <!-- no image --> <div>* Britain has already secured 100 million doses (Recasts headline and lead)<div class="feedflare"> <a href="http://feeds.reuters.com/~ff/reuters/UKBankingFinancial?a=6BMv6EZF-WU:YrGQl_3p3BA:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/reuters/UKBankingFinancial?d=yIl2AUoC8zA" border="0"></a> <a href="http://feeds.reuters.com/~ff/reuters/UKBankingFinancial?a=6BMv6EZF-WU:YrGQl_3p3BA:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/reuters/UKBankingFinancial?i=6BMv6EZF-WU:YrGQl_3p3BA:V_sGLiPBpWU" border="0"></a> <a href="http://feeds.reuters.com/~ff/reuters/UKBankingFinancial?a=6BMv6EZF-WU:YrGQl_3p3BA:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/reuters/UKBankingFinancial?i=6BMv6EZF-WU:YrGQl_3p3BA:F7zBnMyn0Lo" border="0"></a> </div><img src="http://feeds.feedburner.com/~r/reuters/UKBankingFinancial/~4/6BMv6EZF-WU" height="1" width="1" alt=""></div> Posted by Reuters