Since the inception of the Trump Administration's "Operation Warp Speed," an effort to quickly make a COVID-19 vaccine available to Americans, the promises have been ambitious.

See the latest progress on the COVID-19 Vaccine on our daily Progress Tracking page.

On May 28, Defense Secretary Mark Esper told the nation, "I’m confident that we will be able to deliver a vaccine at scale in time."

This confidence is so great, manufacturers have begun production of a vaccine that hasn't completed clinical testing. The production rate is so great, there is concern we'll run out of glass vials to store them. The rate of production has some experts concerned about the safety of the future vaccine.

Nevertheless, the five finalists selected by OWS are moving steady on the record breaking timelines. Pfizer, one of the five finalists claimed their vaccine may be available as early as October.

Today, an unnamed source in the White House administration spoke with Yahoo News taking a different tone, "We cannot promise a 100 percent chance of success. What we can tell Americans is that we’ve taken every possible step to maximize the probability of success."

The senior official shied away from the previous January 2021 expectation saying instead "by the height of flu season next year we have enough vaccines and we have vaccinated those who are vulnerable — and desire a vaccine — to protect as much life as possible" and echoing Esper's language adding, "We’re confident that we will hit that objective."

The administration expects to take a tiered approach to distributing the vaccine, once available, giving preference to the elderly and most vulnerable. The official downplayed the concern for a large population needing the vaccine once available:

"We fully expect there will be … 20, 30, 40 million Americans that probably have strong antibodies to coronavirus by the end of the year, so they would be a significantly lower priority."