GSK Plc raised its guidance for the second time this year as demand surges for its breakthrough vaccine to prevent a common respiratory virus in adults.

The UK pharmaceutical company now expects sales to increase by as much as 13% and adjusted earnings per share to rise as much as 20% this fiscal year. The high end of each range is 3 percentage points above previous forecasts.

The pickup in performance has been driven in part by the successful launch of Arexvy, the new respiratory syncytial virus vaccine for older adults.

Arexvy was launched in the US in August and is also available in some other markets. Demand has been high and third-quarter sales of £700 million ($850 million) were double what analysts were expecting. GSK said its RSV shot, which can provide protection for two winter seasons, should now hit as much as £1 billion this year.

On Tuesday, Pfizer Inc., which has a rival RSV shot, Abrysvo, for adults that provides protection for one season, said it recorded $375 million of sales in the quarter, its first full three months on the market.

The successful launch of Arexvy comes as GSK seeks to build its pipeline of new treatments after splitting its pharma business from the consumer-products unit that made Centrum vitamins last year. Led by Chief Executive Officer Emma Walmsley, GSK is pursuing a number of development areas, which could help compensate for the loss of exclusivity on some of its best-selling drugs, including a key HIV treatment.

GSK’s vaccine sales rose by 33% during the period, also helped by its blockbuster shingles vaccine Shingrix. The UK company recently signed a £2.5 billion deal with China’s Zhifei as it aims to double global sales of Shingrix by 2026.

Walmsley, who has faced pressure from investors to revamp the pipeline, said GSK is now on a strong and broad-based trajectory of growth.

--With assistance from Chloé Meley.

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