MedImmune Inc. said yesterday that federal regulators asked only a few final questions about its nasal-spray flu vaccine FluMist, signaling an earlier-than-expected willingness to approve the drug.

A letter from the Food and Drug Administration, which arrived Wednesday, requested additional information about FluMist but asked for no new human tests, the company said. Chief executive David M. Mott said he did not regard any of the questions as "impediments" to approval. Such a letter, which was not expected until the end of February, typically presages a decision on a new drug.

An FDA advisory panel last month recommended that FluMist be approved, but only for use by healthy people ages 5 to 49. Such approval would exclude very young and older patients, who are most susceptible to influenza.

MedImmune's stock closed yesterday at $29.86 a share, up $1.96.

The Gaithersburg biotechnology company also reported yesterday that fourth-quarter earnings fell 14 percent. Higher sales of its respiratory drug Synagis were offset by the cost of purchasing and operating vaccine-maker Aviron last year.

MedImmune said that for the three months ended Dec. 31, profit fell to $84.6 million (33 cents a share), from $98.5 million (45 cents a share) in the fourth quarter of 2001.

A 25 percent increase in Synagis sales for the quarter boosted revenue to $381.8 million, from $292.7 million in the same period a year earlier. Synagis, which accounts for nearly 80 percent of MedImmune's revenue, fights a serious lower respiratory infection that generally strikes in the winter.

"Synagis has no competition," said Dennis Harp, a Deutsche Bank analyst. "And it's growing faster outside the United States than it is growing inside the country."

For the year, MedImmune reported a loss of $1.1 billion ($4.40 a share), compared with a profit of $149 million (68 cents) in 2001. The company said the loss included a $1.2 billion charge related to the purchase of Aviron, now called MedImmune Vaccines, the deal through which it acquired FluMist.