Lonza, which in September began "large-scale production" in the United States and expects Swiss production to start this year, made the announcement after Moderna said its vaccine candidate showed 94.5% efficacy, according to interim data.

Moderna, whose vaccine requires two doses per person, has said it remains on track to produce between 500 million and 1 billion doses annually by 2021, while planning U.S. shipments of about 20 million doses already this year.

Basel-based Lonza is building four production lines -- one in Portsmouth, New Hampshire, and three in Visp deep in the Swiss Alps -- for $60-70 million each, with each line capable of producing 100 million doses. Moderna has its own production capacity, too.

Lonza has previously said it could potentially increase production capacity for Moderna's vaccine, including at a site in Singapore or in Switzerland, although a spokesperson said on Monday the company is initially focused on completing the four production lines now in the works.

"With positive interim results from both Moderna's and Pfizer's mRNA vaccine candidates, we are witnessing a major step forward in the evolution of vaccine technology, with the potential to change the way we manage infection and disease in the future," said Lonza Chief Executive Pierre-Alain Ruffieux in a statement.

(Reporting by John Miller; Editing by Michael Shields)