Johnson & Johnson stock climbed 8% Monday after the company said human testing of its experimental vaccine for the coronavirus will begin by September and it could be available for emergency use authorization in early 2021.

J&J also said it has committed more than $1 billion of investment in partnership with the federal Biomedical Advanced Research and Development Authority, which is part of the Department of Health and Human Services, to co-fund vaccine research.

J&J's lead vaccine candidate will enter a phase 1 human clinical study by September, the company said, and clinical data on its effects is expected before the end of the year. If the vaccine works well, the company said it could be available for emergency use in early 2021.

The company said it is also increasing its manufacturing capacity with a new site in the U.S. and additions to existing sites in other countries to produce and distribute the potential vaccine quickly. J&J said it seeks to produce more than 1 billion doses of the potential vaccine.

"We have very good early indicators that not only can we depend on this to be a safe vaccine base but also one that will ultimately be effective based on all the early testing and modelling we've been doing," Chairman and CEO Alex Gorsky said Monday on CNBC's "Squawk Box." "This is a bit of a moonshot for J&J going forward, but it's one we feel is very, very important for use to be doing at this period in time."