The federal government will invest 300 million euros ($337 million) to take a 23-percent stake in CureVac, based in Tuebingen in southwest Germany.

"We don't know which company will bring the first workable vaccine to market," Altmaier told reporters in the capital. "But we know that CureVac is among those in the lead."

Die Welt newspaper reported that Berlin's move was aimed at preventing CureVac from falling into foreign hands as the firm plans a listing on the New York-based Nasdaq stock exchange as early as next month.

"It is of particular interest to the state to secure a basic supply of the vaccine for the German population," Die Welt quoted from a finance ministry document reportedly sent to the German parliament.

In March, a different newspaper report alleged that the Trump administration had attempted to buy exclusive rights to CureVac's vaccine research. 

Though company and US officials dismissed it as unfounded, the report caused outrage in Berlin and prompted minister Altmaier to declare that "Germany is not for sale".

The German government last month gave itself new powers to stop hostile takeovers of healthcare companies, in the latest sign that the global race to secure potentially game-changing vaccines or treatments was heating up.

Under the new rules, a health company must notify Berlin if a buyer outside the EU seeks a stake of more than 10 percent -- compared with a previous threshold of 25 percent.

 

'Great potential'

Billionaire Dietmar Hopp -- a co-founder of European software giant SAP -- had until now been the major investor in CureVac, holding more than 80 percent of the shares.

CureVac's technology, based on molecules known as "messenger RNA" (mRNA) that are found within the body, offers "great for potential for vaccines for COVID-19 but also many other infectious diseases, as well as therapy options for many other indications," Hopp told reporters via video link.

Vaccines based on mRNA "have the potential to protect people with a very low dose" and do not need to be refrigerated, acting chief executive Franz-Werner Haas added, simplifying the logistics of inoculating large numbers of people.

Germany's CureVac intervention comes days after Berlin, Paris, Rome and The Hague said they had signed an agreement to procure up to 400 million doses of a potential coronavirus vaccine from pharmaceutical group AstraZeneca.

The agreement calls for all EU member states to receive supplies of the vaccine as soon as it is discovered.

AstraZeneca is working with Oxford University on a highly-publicized vaccine candidate, with trials on 10,000 participants getting underway.