The vice presidential debate has taken on an outsize and perhaps unprecedented significance, with questions about President Donald Trump’s health now looming over the US election less than a month away.US Vice-President Mike Pence’s face-off against Senator Kamala Harris, Democrat Joe Biden’s running mate, on Wednesday (Thursday morning Hong Kong time) in Salt Lake City comes as the Trump campaign continues to reel from a Covid-19 outbreak that has infected the Republican president and a…