Moderna’s researchers say the current vaccine may be less effective against the South African Covid strain. CNBC’s senior health and science reporter Meg Tirrell joins Shep Smith to discuss. Dr. Kavita Patel, former Obama White House health policy director, says we may have to get regular boosters to fight Covid-19. The House impeachment managers formally triggered the start of former President Donald Trump's second impeachment trial today. Melissa Murray, New York University professor of law, says many constitutional lawyers have said it may be possible to convict former President Trump, even though he’s no longer in office. Plus, Biden’s Coronavirus relief package and a billion dollar lawsuit against Rudy Guiliani.