Moderna on Monday reaffirmed its forecast of $6 billion to $8 billion in COVID vaccine sales for the year, after rival Pfizer slashed forecast for its vaccine last week.

Moderna said it will have "improved visibility" about the expected U.S. market size for vaccines after observing trends through October 2023.

Shares of Moderna were down about 4% in premarket trading.

(Reporting by Bhanvi Satija in Bengaluru; Editing by Shilpi Majumdar)