Swiss pharmaceuticals giant Novartis said Friday it had signed an initial agreement to help produce the Pfizer-BioNTech vaccine against Covid-19, as countries scramble to boost supplies.

The rare act of cooperation -- in an industry usually marked by cut-throat competition -- comes after French pharma group Sanofi announced earlier this week that it would also team up with rivals Pfizer and BioNTech to help produce 125 million doses of their jab.

The two-dose vaccine, which is based on mRNA technology, has been shown to be around 95 percent effective and has been approved for use by the World Health Organization and in some 50 countries.

But it is in limited supply as nations around the world race to immunise their populations against the coronavirus, which has killed nearly 2.2 million people in just over a year.

Novartis said in a statement that it would use its sterilised manufacturing facilities at its site in Stein, Switzerland to help produce the Pfizer-BioNTech jabs.

Under the agreement, the company said it would "take bulk mRNA active ingredient from BioNTech and fill this into vials under aseptic conditions for shipment back to BioNTech for their distribution to healthcare system customers around the world".

Once a final agreement is reached, Novartis said it expected to begin production in the second quarter of the year, with initial shipment of finished product expected in the third quarter.

Steffen Lang, Head of Novartis Technical Operations, stressed that the company was "committed to leverage our manufacturing capabilities to help support the supply of COVID-19 vaccines and therapeutics around the world".

"We expect this to be the first of a number of such agreements," he said in the statement.

Novartis said it was already in "advanced discussions" with a number of other companies about with other production tasks, including of mRNA, therapeutic protein and raw material production for Covid vaccines and therapeutics.