Moderna says Covid-19 vaccine immunity to stay at least a year

The company's vaccine uses synthetic mRNA to mimic the surface of the coronavirus and teach the immune system to recognise and neutralise it

Immunity from Moderna Inc's Covid-19 vaccine should last at least a year, the company said on Monday at the JP Morgan Healthcare conference.

The drugmaker said it was confident that the messenger RNA (mRNA) technology it used was well suited to deploy a vaccine based on the new variant of the coronavirus which has emerged in a handful of countries.

The company's vaccine, mRNA-1273, uses synthetic mRNA to mimic the surface of the coronavirus and teach the immune system to recognise and neutralise it.

Moderna said in December it would run tests to confirm the vaccine's activity against any strain.

The company said on Monday it expects to deliver between 600 million doses and 1 billion does of its vaccine in 2021 and forecast vaccine-related sales of $11.7 billion for the year, based on advance purchase agreements signed with governments.

"The team feels very comfortable with the track record we have now ... that we are on track to deliver at least 600 million doses," Chief Executive Officer Stéphane Bancel said.