Pfizer Inc on Tuesday forecast $26 billion in COVID-19 vaccine sales this year, a more than 70% jump from its last projection, reflecting new contracts with governments around the world trying to halt the pandemic through rapid vaccination.

The raised goal assumes 1.6 billion doses of vaccine, which is co-developed with BioNTech SE, will be delivered in the year, with the two-shot vaccine emerging as the best-selling product for the US drugmaker in the first quarter.

It is expected to make up for more than one-third of Pfizer's full-year sales, with the company in supply talks with several countries for 2022 and beyond.

"Based on what we've seen, we believe that a durable demand for our COVID-19 vaccine - similar to that of the flu vaccines - is a likely outcome," Chief Executive Albert Bourla said in his prepared remarks.

Cost and gross profit from the vaccine are split 50-50 between Pfizer and BioNTech. The two drugmakers had said they aim to produce up to 2.5 billion doses this year, of which 900 million doses have not been included in Pfizer's forecast.

If it sells that number of doses, the vaccine sales in 2021 could be at least 50% higher than the projected $26 billion.

The company has said it expects to profit from the vaccine, while some drugmakers including Johnson & Johnson have said their vaccine will be available on a not-for-profit basis until the end of the pandemic.

Pfizer aims to manufacture at least 3 billion doses of the vaccine next year. It generated $3.5 billion in revenue in the first quarter and beat estimates of $3.28 billion, according to six analysts polled by Refinitiv.

Rival Moderna has forecast $18.4 billion in 2021 sales of its COVID-19 vaccine.

Pfizer said it was using the technology used in the COVID-19 shot known as messenger RNA to develop two flu vaccines that are expected to enter clinical studies in the third quarter.

Shares the company were up 1.4% in premarket trading.