Delta variant spreads as Pfizer looks to administer third shot
The Delta variant now accounts for more than half of new coronavirus cases in the U.S., and almost all of the new cases are among people who have not been vaccinated. The spread of the highly contagious variant comes as restrictions have been lifted in almost all of the U.S. and as vaccine maker Pfizer asks for emergency authorization to administer a third shot. Michael George has the latest.