Weekend Roundup

On the CBS News "Weekend Roundup," with host Allison Keyes, the highly contagious Delta variant of Covid-19 now accounts for more than 80 percent of new coronavirus cases in the nation. The World Health Organization says it is also fueling a global surge in new infections, sparking a debate over whether face coverings are needed again. Allison asks CBS News Medical contributor Dr. David Agus what he thinks. Mask mandates are varying in schools across the nation, including in states like Georgia. Reporter Adam Murphy explains. Florida, Mississippi and Arkansas are among the states being hit the hardest right now. CBS's David Begnaud went to Louisiana, which reported one of its highest single day totals this week -- since the pandemic began. Opening ceremonies went on as planned Friday for the Tokyo Olympics amid serious worries over Covid-19. We get the latest from CBS's Steve Futterman who reports from the stadium. On Friday morning, Attorney General Merrick Garland met with law enforcement officers