Feb 22 (Reuters) - Moderna on Thursday reported a surprise fourth-quarter profit helped by cost cutting and some deferred payments, and the vaccine maker set out a commercial roadmap for its experimental respiratory syncytial virus (RSV) shot.

Moderna posted a profit of $217 million, or 55 cents a share, for the quarter. Analysts had expected a loss of 97 cents a share, according to LSEG data.

Moderna Chief Financial Officer James Mock in an interview said the company beat its own forecast because of unexpected deferred revenue of $600 million and cost savings of around $300 million created by the company's effort to adjust its manufacturing output last year.

"Our resizing was mostly completed at the end of the third quarter, but there is still plenty of work to do to drive additional productivity," he said.

The Cambridge, Massachusetts-based drugmaker reported fourth quarter sales of $2.8 billion from its COVID-19 vaccine, its only commercial product, which was down 43% from 2022 but in line with analysts' expectations.

Moderna recorded $6.8 billion in sales from its COVID vaccine in 2023, down from $18.4 billion in 2022 but slightly above Wall Street estimates of $6.7 billion.

Mock said production was not stalled last September after the U.S. Food and Drug Administration found control lapses at Moderna's main manufacturing plant.

The company has been banking on the success of its experimental shots including for RSV, influenza and cancer to make up for declining COVID revenue.

Moderna said it expects a U.S. approval decision for its RSV shot by May 12, in time for the U.S. Centers for Disease Control and Prevention to consider usage recommendations at a vaccine meeting in late June.

The company said it also planned to launch its RSV shot, called mRNA-1345, in Germany and Australia this year.

Analysts estimate the shot will generate $280 million in 2024.

Data posted earlier this month showed the vaccine was 63%effective at preventing RSV-related respiratory symptoms after 8.6 months, down from 84% at 3.3 months.

The results raised concerns among investors over faster efficacy declines compared with rival shots from GSK and Pfizer, both of which launched last year.

Moderna said on Thursday it also expected data from late-stage trials of its next generation COVID shot and its cytomegalovirus and COVID-flu combination vaccines this year.

In November, the company pushed back the launch of its flu shot from 2024 to the following year. It said it intends to file for approval this year.

Moderna said it was participating in the EU Health Emergency and Response Authority’s tendering procedure for up to 36 million doses of COVID vaccines per year for up to four years as part of an effort to prioritize key international markets.

Mock said he was not sure how long the EU tender would take, but would "imagine a decision in the coming months" in time for the fall market.

The company reaffirmed its 2024 forecast of $4 billion in sales, the lowest figure for annual revenue since its COVID vaccine got U.S. emergency authorization in late 2020.

Analysts on average estimate the company will bring in $4.48 billion in 2024 revenue, down 33% from 2023.

"Last year was a year of transition that we had to do, and the volume was not quite what we had expected it to be," Mock said. "We took actions to resize the company and we're excited to execute in 2024."

(Reporting by Patrick Wingrove in New York and Leroy Leo in Bengaluru; Editing by Bill Berkrot)