President Joe Biden on Thursday defended the move to issue sweeping vaccine mandates for federal contractors, healthcare workers, and private-sector employees. The Department of Labor issued a vaccine-or-test requirement to tens of millions of private-sector employees at workplaces with 100 or more workers with a Jan. 4 deadline, which has sparked concerns of worker shortages in key industries amid supply-chain bottlenecks. Federal contractors and most healthcare workers have a Jan. 4 deadline to get vaccinated without the option to submit to weekly testing under the rule. “As we’ve seen with businesses—large and small—across all sectors of our economy, the overwhelming majority of Americans choose to get vaccinated,” Biden said in a statement, echoing claims made last week by his COVID-19 advisor, Jeff Zients. “There have been no ‘mass firings’ and worker shortages because of vaccination requirements. Despite what some predicted and falsely assert, vaccination requirements have broad public support.” Biden …