Johnson & Johnson has signed a $1 billion deal with the U.S. Department of Health and Human Services with the goal of creating more than one billion doses of a vaccine it’s developing against the novel coronavirus, the company said Monday.

The drugmaker said it has identified a lead COVID-19 vaccine candidate and expects to begin Phase 1 human testing by September 2020. And if all systems are go, the first batches of a COVID-19 vaccine could be ready for emergency use by early 2021.

This timeline indicates an extremely expedited vaccine-development process: Potential vaccines typically undergo a slew of research stages spanning five to seven years before being put up for approval, with the whole process taking up to 15 years, start to finish. And normally, animal testing would precede human testing. But under immense pressure stemming from the ongoing pandemic, many vaccine developers are fast-tracking the process and taking shortcuts that skip this step—such as the Cambridge, Massachusetts-based biotechnology firm Moderna, which was the first to inject a trial COVID-19 vaccine into a human subject earlier this March.

As of now, only two vaccine developers have reached Phase 1 testing: Moderna and the China-based biotechnology firm CanSino Biologics.

Alex Gorsky, CEO of Johnson & Johnson, issued this statement about the deal:

“The world is facing an urgent public health crisis and we are committed to doing our part to make a COVID-19 vaccine available and affordable globally as quickly as possible. As the world’s largest healthcare company, we feel a deep responsibility to improve the health of people around the world every day. Johnson & Johnson is well positioned through our combination of scientific expertise, operational scale and financial strength to bring our resources in collaboration with others to accelerate the fight against this pandemic.”

The $1 billion deal is a big expansion on an existing $456 million partnership formed on March 27, according to Forbes, between Johnson & Johnson’s pharmaceutical arm, Janssen, and the Biomedical Advanced Research and Development Authority. Their latest investment is the most money spent on a vaccine project to date.

Johnson & Johnson also announced a collaboration between Janssen and Beth Israel Deaconess Medical Center on March 13, which aims to surface COVID-19 vaccine candidates using the same technology used to identify Ebola, Zika, and HIV candidates.