The head of the Food and Drug Administration (FDA) said his agency would move quickly to authorise the Moderna vaccine, allowing the company to begin shipping millions of doses.

It comes days after the US began its rollout of the Pfizer/BioNTech jab.

The US has recorded more coronavirus cases and deaths than any other country.

Earlier this week, the death toll passed 300,000.

The advisory panel on Thursday voted 20-0 with one abstention that the benefits of the Moderna vaccine outweigh the risks for those aged 18 and over. The same committee last week backed the Pfizer/BioNTech vaccine, leading to its authorisation for emergency use the following day.

Following the panel's endorsement, FDA Commissioner Stephen Hahn said his agency had informed Moderna that it would "rapidly work toward finalization and issuance of an emergency use authorization".

Regulators reported earlier this week that

the Moderna vaccine was safe and 94% effective.

The US has agreed to purchase 200m doses, and 6m could be ready to ship as soon as the vaccine gets FDA approval.

The Moderna vaccine requires temperatures of around -20C for shipping - similar to a normal freezer.

The Pfizer jab requires temperatures closer to -75C, making transport logistics much more difficult.

Like the Pfizer jab, the Moderna vaccine also requires a second booster shot. Moderna's second injection comes 28 days after the first.

The company is based in Cambridge, Massachusetts, and has said that if approved, the "vast majority" of its vaccine would be manufactured there.

Pfizer's drug is being manufactured in several countries, including Germany and Belgium.

In Canada, the government plans to get two million Moderna doses by March - part of a total 56m doses.

The UK has already pre-ordered 7m doses of the Moderna vaccine.

The European Union last month announced a contract to purchase of 80m doses - with an option to purchase up to 80m more - once the vaccine is deemed safe and effective.

Japan has signed up for 50m Moderna doses, South Korea for 20m, and Switzerland has ordered 7.5m, according to data compiled by the Duke University Global Health Innovation Center.