Pfizer's Chief Executive Albert Bourla has said that an annual COVID-19 vaccine would be preferable to more frequent booster shots in fighting the coronavirus pandemic.

Pfizer/BioNtech's COVID-19 vaccine has shown to be effective against severe disease and death caused by the heavily-mutated Omicron variant but less effective in preventing transmission.

With cases soaring, some countries have expanded COVID-19 vaccine booster programmes or shortened the gap between shots as governments scramble to shore up protection.

In an interview with Israel's N12 News, Bourla was asked whether he sees booster shots being administered every four to five months on a regular basis.

"This will not be a good scenario. What I'm hoping (is) that we will have a vaccine that you will have to do once a year," Bourla said.

"Once a year—it is easier to convince people to do it. It is easier for people to remember.

"So from a public health perspective, it is an ideal situation. We are looking to see if we can create a vaccine that covers Omicron and doesn't forget the other variants and that could be a solution," Bourla said.

Bourla has said Pfizer could be ready to file for approval for a redesigned vaccine to fight Omicron and mass produce it, as soon as March.

Citing three studies, the US Centers for Disease Control and Prevention (CDC) said on Friday that a third dose of an mRNA vaccine is key to fighting Omicron, providing 90 per cent protection against hospitalisation.

(PTI)