Nearly £5bn wiped off value of GSK as US restricts blockbuster respiratory vaccine

Nearly £5billion was wiped off the value of GSK after a top US health agency limited the scope of its blockbuster respiratory vaccine.

In a further setback for the UK pharmaceutical giant, the US public health agency, the CDC, said that respiratory syncytial virus (RSV) jabs should not be given to under-60s.

The ruling came just weeks after GSK was given the green light by the US Food and Drug Administration (FDA) to expand the use of its Arexvy vaccine from those aged over 60 to those aged between 50 and 59.

While the FDA is the body that gives the formal licence for vaccines in the US, it is up to the CDC to recommend how they are used, and by whom.

Vaccine blow: GSK shares tumbled as much as 7% – wiping £4.8bn off its value – before closing down 4.6%, or 73.5p, at 1526p

GSK shares tumbled as much as 7 per cent – wiping £4.8billion off its value – before closing down 4.6 per cent, or 73.5p, at 1526p.

RSV causes cold-like symptoms but can be dangerous for the elderly and vulnerable as well as babies.

The jab has the potential to prevent thousands of hospital admissions each year.

But in a shock move, the CDC did not vote on implementing the FDA’s age guidance.

According to estimates from Jefferies, the recommendation could slash the number of jabs GSK administers in the US from 93m to 55m.

Peter Verdult at Citi said peak sales would be ‘materially’ lower than the £3billion a year pencilled in by analysts.

Shares in Moderna and Pfizer, which also make RSV vaccines, fell 1.5 per cent and 1.1 per cent respectively yesterday.

GSK’s setback comes just days after the FTSE 100 group lost out to Pfizer in a deal that will see the US group provide 4.9m RSV jabs to older adults and pregnant mothers in England and Northern Ireland over the next two years.

GSK said that it was ‘disappointed’ by the result but remained ‘very confident’ in its jab.

The success of Arexvy up until recently has been a major boost for chief executive Emma Walmsley as she pushes ahead with her turnaround strategy at the pharma giant.

It has offloaded its consumer healthcare division Haleon as she refocuses on vaccines and infectious diseases.

The shift came after GSK fell behind rival AstraZeneca and Pfizer to create a Covid vaccination during the pandemic.

Arexvy brought in some £1.2billion of sales in 2023 – well ahead of the £699million that its rival Pfizer generated from its own shot.