Support WBURFlu Threat Looms As Mecca Readies For PilgrimsPlay04:15Download AudioKelly McEversNovember 06, 2009 ShareHundreds of thousands of Muslim pilgrims circle the sacred Kaaba stone at Mecca's Grand Mosque in December 2008. Saudi Arabian authorities are concerned about the effects the H1N1 pandemic will have on this year's pilgrimage. (AFP/Getty Images)