Pfizer's (PFE) COVID-19 vaccine is nothing short of a blockbuster drug for the company, bringing in $3.5 billion in revenue in the first three months of this year, nearly a quarter of its total revenue, Pfizer announced today in its first-quarter results. The company now expects full-year sales of $26 billion from the vaccine, up from its previous forecast of about $15 billion.

Unlike smaller biotechs whose valuations have soared from vaccine sales — including vaccine partner BioNTech (BNTX) — Pfizer's stock has remained relatively stable — even on days with news of positive clinical trials.

"We do think our stock is undervalued, but we do not worry that investors cannot see it," CEO Albert Bourla told Yahoo Finance Tuesday.

CFO Frank D'Amelio said the company's stock has had a nice run up, but "there's a lot more value to unlock. Investors will start to warm up more to the story," especially if the company can continue to deliver results like it did this quarter in concert with its longer-term view, D'Amelio added.

"We had a blowout quarter. We really had a solid quarter," he said. "We believe we can grow the top line at least 6% through 2025 and bottom line 10-11%," D'Amelio added.

The company, which has a broad portfolio that includes traditional vaccines, was one year into a new strategy moving away from generics and into more targeted products when the pandemic hit and it pivoted to developing MNRA shots. The company is also looking to supplement growth with mergers and acquisitions.

Vaccine sales

Bourla said during an earnings call Tuesday that "basically all governments in the world" are discussing dose commitments through 2024. And the company is able to meet new demand for the year, with a 2.5-billion dose production target. So far, the projected $26 billion in sales accounts for 1.6 billion doses.

In the U.S., vaccine demand is waning and some of the harder-to-reach or hesitant populations remain.

The addition of the pediatric population, starting with a likely authorization for 12-15 year-olds in the near future, will help to buoy any slowdown in revenues, Bourla said.

Chief Scientific Officer Mikael Dolsten told Yahoo Finance Tuesday that the younger population is likely to need boosters annually, even though as of now the initial booster market focus is for the elderly and other vulnerable people.

"We are likely to see regular immunization," Dolsten said.

More from Anjalee:

• Moderna can't afford to share its vaccine technology, CEO says

• China, Russia playing 'greater-than-expected' roles in global pandemic response

• Biden COVID-19 adviser: Vaccine news is great, but we still have a ways to go

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