The U.S. stock market could roar higher if President-elect Joe Biden is able to smooth out the country’s rocky start to Covid vaccinations, CNBC’s Jim Cramer said Wednesday, just a few hours before the Democrat is sworn into office.”It’s pure chaos. I predicted it would be pure chaos. I never thought it would be this bad,” Cramer said of the vaccine rollout on “Squawk Box.” “If President Biden just says on Day One, ‘It’s a do-over. We’ve got plans, military get ready,’ I think this market could explode.”There is a need for additional stimulus to support Americans and businesses who have been hurt by the pandemic, Cramer said. However, he contended the most necessary fuel for the stock market to continue its robust recovery from pandemic-era lows is a timely manner of vaccine distribution and administration.”I think we’re all beleaguered. I think an orderly transfer of power, coupled with a well-defined plan to give us vaccines as they roll out, will make it so this market can go up tremendously,” the “Mad Money” host said. “Everything else, I’m not saying it’s irrelevant but you can’t get this economy open until we’ve figured out how to get the vaccines from Pfizer and Moderna into our arms.”Biden has pledged to administer 100 million doses in his first 100 days. Last week, he detailed his plan to do so, which includes tapping the National Guard and the Federal Emergency Management Agency to set up large-scale vaccination sites across the country. Biden also plans to accelerate the availability of Covid vaccines at local pharmacies.Cramer said he believes Biden’s plan to have the federal government play a more active role in the administration of vaccines is necessary. Even so, Cramer said Biden has set a high bar with his 100-day vaccine pledge.”I think it is going to be a clock unlike any we have ever seen, where there is a belief that right now there is a plan. When you set out those expectations, the clock starts at noon,” said Cramer, 65, who has received his initial dose of the vaccine.As of Tuesday morning, the U.S. has administered 15.7 million vaccine doses, according to data compiled by the Centers for Disease Control and Prevention. There have been 31.2 million doses distributed.