Moderna Inc. plans to spend billions of dollars to increase production of Covid-19 vaccines and potentially triple its yearly output of doses in 2022, as the company seeks to meet rising global demand.The Cambridge, Mass., biotech company stated on Thursday that it could produce up to three billion doses of Covid-19 vaccines in 2022, compared with a projected output of up to one billion this year.Moderna also stated that it would make no less than 800 million doses this year, up from a minimum 700 million it had previously predicted.The boosted output is a new indication that Western Covid-19 vaccine makers, after a sluggish start, are expanding their manufacturing capabilities as they gain more experience making the shots.