The vaccine, among the first to be tested in humans in the United States, was found to produce protective antibodies in a small group of healthy volunteers.
Under the deal, Catalent will provide manufacturing services for an initial 100 million doses starting in the third quarter at its facility in Bloomington, Indiana.
It will also provide other packaging and labeling, storage and distribution services at its facilities in Philadelphia, Pennsylvania to support Moderna's late-stage vaccine trial, which is expected to begin in July.
Drugmakers including Johnson & Johnson and AstraZeneca Plc have also signed agreements to boost manufacturing capacity for their experimental vaccines even before having adequate evidence of their efficacy.
There are no approved treatments or vaccines for COVID-19 and experts have cautioned that a safe and effective vaccine may take at least 12 to 18 months from the start of development.
Vaccines by other drugmakers including Johnson & Johnson, Sanofi and AstraZeneca Plc are in various stages of development and about a dozen vaccines are currently being tested in humans.
Both Moderna and Catalent are also in talks for making hundreds of millions of additional doses.
Separately, Moderna has struck deals with the US government for funds to ramp manufacturing capacity, while also entering into a 10-year collaboration with Swiss contract drugmaker Lonza Group AG to produce large quantities of its vaccine.
Shares of Moderna were up 2.5% at $66.48 in premarket trading.