The United States could start injecting the first Americans with the Pfizer-BioNTech Covid-19 vaccine by Monday, the country's health secretary said Friday.

Alex Azar told news channels that final details were being ironed out, after an expert committee convened by regulators voted to grant the two-dose regimen emergency approval for people aged 16 and over.

The Food and Drug Administration issued a statement Friday saying it had told Pfizer it would now "rapidly work toward finalization and issuance of an emergency use authorization."

Azar told ABC News that authorities were working with Pfizer on logistics and "we could be seeing people get vaccinated Monday, Tuesday of next week."

"So, it's very close. It's really just the last dotting of I's and crossing of T's," he added.

Those outstanding matters include getting a fact sheet ready for doctors, Azar told Fox Business.

Once the vaccine receives an Emergency Use Authorization (EUA), the federal government's Operation Warp Speed program will oversee its distribution to thousands of sites across the country.

Before that happens, a committee from the Centers for Disease Control and Prevention (CDC) also has to recommend the vaccine, then the agency itself has to accept that recommendation. 

The first of these meetings takes place on Friday and the second on Sunday, but they are at this stage viewed as pro forma. 

Thursday's expert committee voted 17 in favor, four against, with one abstention, on the matter of approving Pfizer's vaccine, which a clinical trial has shown to be 95 percent effective. 

Some of the experts who voted no were concerned by the condensed follow-up time that has been adopted for Covid vaccine studies compared to other vaccines.

Most scientists, however, accept that while the data is not yet perfect, the surging nature of the pandemic -- nearly 300,000 people have died in the US alone -- means that the risk-benefit calculus has to be changed. 

Next week, an FDA committee will meet to consider a second vaccine, developed by Moderna and the National Institutes of Health. 

Both frontrunner vaccines are based on new messenger RNA technology, which have never been approved before but could potentially revolutionize the field.

The US hopes to immunize 20 million people this month, 100 million by February, and the whole population by June.

Long-term care facility residents and health care workers are at the front of the line.