This weekend marks the addition of a third COVID-19 vaccine to America's arsenal against the pandemic. Johnson & Johnson's one-dose inoculation joins Pfizer and Moderna's two-dose vaccines for use in the United States. 
As impressive as the scientific advancements have been, getting shots into people's arms has been plagued by bad weather, bad logistics and bad information. 
The Biden administration's coronavirus coordinator Jeff Zients, in his first television interview since taking the job, tells us there has been real progress over the past month on vaccine distribution. But with just over 50 million vaccine doses given since President Biden took office, the American public still needs patience.
Jeff Zients: We hit a grim milestone on Monday. 500,000 people have died from COVID in the U.S. And everyone's life has been impacted. You know, too many businesses and schools are no longer open. So this is a national emergency, a war. 
Bill Whitaker: President Biden said the other day that the rollout was a mess when you took office. What was the situation you inherited? 
Jeff Zients: I wanna start by giving credit where credit is due, which is to the scientists and the researchers and the people who participated in the clinical trials. It enabled us to have two vaccines ready in really a record-period of time and these two vaccines are very effective. So that was the good news. The bad news is there really was no plan to ramp up the supply of those vaccines. So there wasn't enough vaccine. There were not enough vaccinators, people actually take vaccine and turn it into vaccinations by putting needles into arms.  And then third there just were not enough places for people to get vaccinated. There was no comprehensive plan or strategy--
Bill Whitaker: When you came into office.
Jeff Zients: when we came into office.
Bill Whitaker: But once you step into the office, this becomes yours. 
Jeff Zients: Right. This is absolutely ours. And President Biden, within the first couple of weeks, secured enough vaccines that by July 31st, there's enough to vaccinate 300 million Americans. 
Bill Whitaker: People are scared. This is life or death for many people. And I think many Americans think that things aren't moving fast enough.  
Jeff Zients: Well I think that's a fair feeling this is life and death. We need to make sure that every day we're getting more and more people vaccinated, we're increasing the supply, we're increasing the number of vaccinations, we're increasing the places where people can go. So I understand the frustration. And we're doing all we can to move as fast as we can. 
Jeff Zients fixed the bungled rollout of the Obamacare website in 2013. Now he's tasked with fixing this vaccine rollout. As part of the plan, the administration has opened seven of 18 mass FEMA vaccination sites, supported more than 400 smaller vaccine centers across the country and has approved distribution of vaccine through pharmacies, targeting under-served communities.  
Dr. Travis Gayles: I think from a federal perspective, there has been significant improvements. They actually have a plan now. 
Dr. Travis Gayles is the chief public health officer for Montgomery County, Maryland, the most populous in the state and one of the most diverse, right next door to Washington D.C.
According to CDC data, Maryland ranks near the bottom when it comes to getting vaccine in people's arms.
The state's most recent weekly allotment shot up to 118 thousand doses - an increase of 55 percent since the start of the biden administration. Even so, dr. Gayles says demand far outstrips supply.  
Dr. Travis Gayles: For example, we have over 72,000 individuals who are over the age of 75 in Montgomery County. We're receiving as a local health department a weekly allotment of 4,500 doses. 
Bill Whitaker: How do you feel about that? 
Dr. Travis Gayles: Extremely frustrated and exhausted.
His department, he told us, is focused on inoculating the most vulnerable and under-served communities hit hard by COVID, but he's having to "prioritize." By that he means identifying the neediest of the needy for the life-saving shot. 
With so many confirmed cases in the United States, it is hoped that the speed of vaccination can exceed the speed of virus infection.