The U.S. will cross a major Covid-19 vaccination landmark on Friday as the number of people who have received at least one Covid-19 vaccine dose is on track to surpass 100 million on Friday, while vaccine supplies in the country are set to receive a boost after the Food and Drug Administration allowed a change that will enable Moderna to put 50% more doses of its vaccine in each vial. Stay Connected Forbes on Facebook: http://fb.com/forbes Forbes Video on Twitter: http://www.twitter.com/forbes Forbes Video on Instagram: http://instagram.com/forbes More From Forbes: http://forbes.com