NEW YORK, Nov 10 (Reuters) - AstraZeneca on Friday said it was prioritizing the U.S. market for additional doses of its respiratory syncytial virus (RSV) drug Beyfortus, which was approved in July to prevent the disease in infants and toddlers, as a surge of cases is outpacing supply.

AstraZeneca CEO Pascal Soriot in an interview at the Reuters office in New York said the U.S. Centers for Disease Control and Prevention (CDC) had been asking for more of the antibody therapy that was co-developed with French drugmaker Sanofi .

“We’ve had to deliver what is needed (for the U.S.) and next year the volume suddenly will go up quite a bit,” Soriot said, noting that the British drugmaker was seeing a surge in demand for the medicine "everywhere."

The CDC was did not immediately respond to a request for comment.

Sanofi on Oct. 20 said it was seeing an "unprecedented level" of demand for Beyfortus. Three days later, the CDC issued an alert saying there was a limited supply of the drug, and advised physicians to prioritize those under 6 months of age or with underlying health conditions.

RSV cases in the U.S. began a sharp upward trend in the middle of October and were at the highest level since January last winter with 4,952 cases detected through testing in the week ended Nov. 4, according to the CDC website. The website also shows an increase in hospitalizations largely among children ages 4 years and under during the same period.

RSV is the top cause of hospitalization among infants, leading to around 1% to 3% of children under 12 months of age being hospitalized in the United States each year, according to the American Academy of Pediatrics.

The U.S. last year saw a surge of children under age 5 being hospitalized for respiratory viruses, including RSV.

Before the approval of Beyfortus, Swedish Orphan Biovitrum had the only approved preventive therapy in the United States for high-risk infants, called Synagis. (Reporting by Patrick Wingrove Editing by Caroline Humer and Bill Berkrot)