Pfizer (PFE -0.19%) enjoyed a record year in 2022. The big drugmaker's revenue topped $100 billion. Its earnings per share soared 42% to $5.47, which translates to nearly $31.4 billion in profits. Both top- and bottom-line numbers set all-time highs.

Everything is going great in Pfizer-land, right? Not so fast. While the company's 2022 full-year and fourth-quarter results announced on Tuesday were great, its guidance for this year wasn't. Pfizer's sales could sink 33% in 2023. But here's why to buy the pharma stock anyway.

Pfizer's gloomy news

We can sum up the reasons behind Pfizer's steep sales decline this year in one word: COVID-19. The company's COVID-19 vaccine Comirnaty generated sales of $37.8 billion last year. Pfizer projects sales of only $13.5 billion in 2023. Oral COVID-19 therapy Paxlovid raked in $18.9 billion last year. Pfizer expects the drug to make only around $8 billion this year.

Pfizer's great results in 2022 are part of the problem. The company sold more doses of both Comirnaty and Paxlovid last year than were actually used. This created inventory stockpiles that will be tapped in 2023, resulting in lower sales. 

That isn't the only issue, though. Pfizer also projects that the number of doses of Comirnaty administered this year will fall by nearly one-third. The company expects fewer primary vaccinations and a lower percentage of individuals receiving recommended booster doses.

Looking beyond COVID, there's even more gloomy news for Pfizer down the road. The big drugmaker expects close to $17 billion in reduced sales between 2025 and 2030 due to several key products losing exclusivity. 

The bigger story

You might think that Pfizer stock is anything but a buy right now based on all of that bad news. However, there's a bigger story for Pfizer that's much more upbeat.

For one thing, the company should enjoy solid sales growth outside of its COVID products thanks to new product launches. Pfizer thinks that the products it launches through the first half of 2024 will generate an additional $20 billion in risk-adjusted annual revenue by 2030. That more than offsets the anticipated sales declines due to older products losing exclusivity.

Pfizer also has a big cash stockpile and ample cash flow to fund additional business development deals. The company is banking on these deals to add another $25 billion or so in new annual revenue by 2030. It's already made significant progress toward this goal. Pfizer estimates that the acquisitions of Arena, Biohaven, Global Blood Therapeutics, and ReViral should generate an additional $10.5 billion in annual sales by 2030.

The longer-term outlook for Pfizer's COVID products isn't as negative as you might think, either. Pfizer believes that 2023 will be a trough year for Comirnaty. However, it expects the number of doses sold to increase significantly between 2024 and 2026. The anticipated launch of a combination COVID-flu vaccine should accelerate sales. 

Pfizer also projects greater sales for Paxlovid beginning in 2024. Importantly, the company's forecast doesn't include any potential sales of the antiviral therapy in China. Should the Chinese government purchase doses of Paxlovid in the future, Pfizer's revenue picture would improve even further. 

An expectations game

My Motley Fool colleague Adria Cimino recently wrote that Pfizer could be a surprise growth pick for 2023. That might seem unlikely considering the company expects its sales to plunge. However, I agree with Adria's conclusion.

Pfizer, like all other public companies, plays a game of expectations. Right now, many investors simply don't have high expectations for the stock. That's apparent based on the fact that Pfizer's shares trade at under 9.5 times forward earnings.

But Pfizer has multiple ways to beat investors' expectations. Its new products could exceed sales targets. Its pipeline might produce more winners than anticipated. The company could make additional acquisitions or licensing deals that boost its growth in a bigger way than investors expect. And, yes, COVID-19 just might be a greater source of long-term revenue and profits than many think it will be.

In my view, Pfizer could easily beat expectations over the next few years. Also, with its attractive dividend, the company pays investors to wait for its return to growth.