Pfizer IncSales of the COVID-19 vaccine developed by the company in cooperation with Germany's BioNTech are expected to bring in $15 billion in revenue, or about 1/4 of total revenue, the company said on Tuesday.

Pfizer Inc said that if the company signs more supply contracts, revenue of the vaccine could exceed 15 billion US dollars. COVID-19 vaccine is expected to become the largest product of Pfizer Inc this year.

Pfizer Inc aims to produce 2 billion doses of COVID-19 vaccine by 2021. Albert Bourla, chief executive, said in an exclusive interview that Pfizer Inc wanted to be conservative about his goals and was studying a number of plans to exceed production targets.

"We have increased weekly production batches, we have doubled the average batch production, we have significantly increased the quality rate, and we have improved the process of the assembly line," Frank D'Amelio, chief financial officer, said in an exclusive interview.

"these are the things we are constantly reviewing to determine what else can be done to produce more vaccines faster," he added.

Pfizer Inc also said that it is expected that there may be a long-term demand for COVID-19 vaccine to combat the emergence of new variants of the virus and to enhance the weakening immune response of the public.

Pfizer Inc estimates that 200 million doses of vaccine will be supplied to the US government by the end of May.

Pfizer Inc will have to produce an average of 10 million doses of vaccine a week to achieve that goal, which is more than twice as fast as Pfizer Inc and BioNTech shipped to the US by the end of January, according to Reuters calculations.

Pfizer Inc estimates that the revenue of the camp in 2021 is expected to be between US $594 and US $61.4 billion. Adjusted earnings estimates for the full year were also raised by $0.1 at each end to $3.10 to $3.20 a share.