A French National Centre for Scientific Research (CNRS) researcher holds a test tube rack containing cells to be infected with Covid-19 during coronavirus vaccine research work inside the Pasteur Institute laboratories in Lille, France, March 9, 2020.

Johnson & Johnson is aiming to produce between 600 million and 900 million doses of its potential coronavirus vaccine by the end of the first quarter of 2021 if human trials scheduled to begin in September go as planned.

It plans to make 1 billion doses or more annually, J&J executives told investors during a post-earnings conference call on Tuesday.

The comments came shortly after the drugmaker raised its quarterly dividend and reported first-quarter financial results that beat Wall Street's expectations.

The company also lowered its 2020 adjusted earnings forecast due to the coronavirus outbreak. It's now expecting a range of $7.50 to $7.90 per share, from its prior estimate of $8.95 to $9.10 per share.

Late last month, the company said human testing of its experimental vaccine for the coronavirus will begin by September and could be available for emergency use authorization in early 2021.

J&J also 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.

On Tuesday, J&J CEO Alex Gorsky reiterated to investors that the U.S. drugmaker would provide the vaccine on a "not-for-profit" basis for emergency use.

The coronavirus, which emerged in China over three months ago, has infected nearly 2 million people worldwide, according to data compiled by Johns Hopkins University. There are no proven therapies to treat Covid-19 and a workable vaccine could take 12 to 18 months, U.S. health officials say.

The first human trial testing a potential vaccine to prevent Covid-19 began on March 16. The company, biotech firm Moderna, is working with the National Institutes of Health, an agency within the Department of Health and Human Services.