(Reuters) - Tesla Inc is building mobile molecule printers to help make the potential COVID-19 vaccine being developed by CureVac in Germany, the electric-car maker’s Chief Executive Officer, Elon Musk, tweeted on Wednesday.

CureVac, an unlisted German company, has said it is developing portable, automated mRNA production units that it calls printers and which Musk described as “RNA microfactories”.

They are being designed to be shipped to remote locations, where they can churn out its vaccine candidate and other mRNA-based therapies depending on the recipe fed into the machine.

But for the immediate pandemic use - should its vaccine candidate win market approval – it has production sites with regulatory approval in Germany with a capacity to produce hundreds of millions of doses.

The company, based in Tuebingen and backed by the Bill & Melinda Gates Foundation, is a pioneer of the so-called messenger RNA approach, which is also pursued by BioNTech and its partner Pfizer as well as Moderna.

RNA molecules are single-stranded versions of the DNA double-helix. Thanks to their recurring molecular pattern, they can be produced in a relatively simple biochemical process that do not require genetically modified living cells, which are needed to produce most other biotech drugs.

CureVac is also building a new stationary site that could increase its output tenfold to billions of doses.

The “microfactories” would be built at Tesla Grohmann Automation in Germany, Musk said in a Twitter thread late on Wednesday night.

Tesla acquired the company that develops automated manufacturing systems for batteries and fuel cells in 2016 to expand its production.

CureVac has been working with Tesla Grohmann to develop the mobile printer technology, a person familiar with CureVac said.

Musk did not elaborate on his plans. Tesla and CureVac were not immediately available to comment.

Musk, who is known to make impromptu announcements on Twitter, had in March said that Tesla has extra FDA-approved ventilators that can be shipped free of cost to hospitals within regions where the electric-car maker delivers.