Johnson & Johnson CEO Alex Gorsky said Monday that he is "absolutely" confident that the company will be able to meet its distribution goals, which include 100 million doses by June and up to a billion by the end of 2021.

Driving the news: J&J is already in the process of shipping 3.9 million doses this week, just days after the FDA issued an emergency use authorization for the one-shot vaccine. Gorsky said he expects vaccines to be administered to Americans "literally within the next 24 to 48 hours."

Why it matters: The J&J vaccine was found by the FDA to be 66.9% effective against moderate to severe COVID-19, and 100% effective at preventing hospitalization.

• Because it's a one-dose vaccine that does not require ultra-cold storage, having 100 million doses of the J&J shot will be crucial in meeting the Biden administration's goal of vaccinating 300 million Americans by the end of July.

What he's saying: Gorsky, appearing on NBC's "Today" one year after he first discussed J&J's vaccine candidate on the show, marveled at how quickly his company's scientists developed the vaccine, stating: " I really can't think of another time in our history where we've been able to ramp up at this kind of pace."

• "This started as literally a genetic code information that was passed on an email about 12 months ago, and since then we've been able to do extensive clinical trials, involving up to 50,000 patients. Trial sites around the world."
• He added, "When we say 100 million doses by June, that means 100 million vaccinations. Patients that will have been treated."

Go deeper: Vaccine supply expected to surge soon