In an earnings forecast released Tuesday, Pfizer (PFE  ) gave lower-than-expected 2023 sales figures for its COVID-19 treatment and vaccine, signaling the start of what Pfizer's CEO Albert Bourla calls a "transition" year for the company.

"We are building on a significant capital position that we know how to deploy to create growth," Bourla said on a call with investors and analysts. "We are building an R&D engine that is more productive than ever."

Pfizer said it expects to see a 64% drop in sales of the Comirnaty vaccine and a 58% decrease in sales of the coronavirus treatment Paxlovid. The two products are predicted to bring in a combined total of $21.5 billion for the year, $3 billion less than Wall Street's forecasts.

Part of the reason for the drop is an anticipated slow start for commercial sales of Comirnaty and Paxlovid this year. The company also expects to see the end of lucrative government contracts to supply a large number of vaccines, with the focus moving to sales on the commercial market.

"We see little here to change our cautious view on Pfizer's ex-COVID business," said Citi (C  ) analyst Andrew Baum.

For 2023, the pharma giant predicts its adjusted earnings will fall between $3.25 and $3.45 per share, compared to analyst forecasts of $4.34 per share. Pfizer says the low earnings expectations are the result of anticipated increases in research and development expenses.

Pfizer has a total of 10 products that see more than $1 billion in annual sales. Two are vaccines, Comirnaty and the pneumonia vaccine Prevnar, and the company has plans to introduce more vaccines in the coming year. Pfizer also brings in billions of dollars from its primary care and cancer drugs.

Last year, Comirnaty alone brought in $37.8 billion in worldwide sales, helping the company top $100 billion in total revenue for the first time. In contrast, Pfizer expects its 2023 revenue to fall closer to $67 billion to $71 billion.

Pfizer saw its profits grow by 43% in 2022 to $31.4 billion. For the fourth quarter, the company reported $24.29 billion in revenue, nearly half of which came from the coronavirus vaccine. The drugmaker reported adjusted earnings for the fourth quarter of $1.14 per share.