With many Americans still planning to visit family and friends, how effective is getting a test before you go?

Huge queues are forming across the US as people rush to get Covid tests ahead of next week’s Thanksgiving holiday.
Despite the US Centers for Disease Control and Prevention (CDC) warning against travel, it seems many Americans are still planning to do so.
So how effective is getting a test before you go? We asked an expert.
Video by Joaquim Salles