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

Nearly £5bn has been wiped off GSK’s value after a top US health agency limited the scope of its successful respiratory vaccine.

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

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

While the FDA is the formal licensing body for vaccines in the U.S., it is up to the CDC to recommend how and by whom they are used.

GSK Share fell as much as 7 percent, losing £4.8 billion of its value, before closing down 4.6 percent, or 73.5 pence, at 1,526 pence.

RSV causes cold-like symptoms, but can be dangerous for older and vulnerable people, as well as babies.

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

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

According to Jefferies estimates, the recommendation could reduce the number of shots GSK administers in the U.S. from 93 million to 55 million.

Citi’s Peter Verdult said peak sales would be “materially” lower than the £3bn a year forecast by analysts.

Shares of Moderna and Pfizer, which also make RSV vaccines, fell 1.5 percent and 1.1 percent 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 4.9 million RSV jabs to older adults and pregnant mothers in England and Northern Ireland over the next two years.

GSK said it was “disappointed” by the result but remained “very confident” in its shot.

Arexvy’s success until recently has been a big boost for chief executive Emma Walmsley as she presses ahead with her turnaround strategy at the pharmaceutical giant.

It has shed its consumer healthcare division, Haleon, to focus again on vaccines and infectious diseases.

The change came after GSK fell behind rivals AstraZeneca and Pfizer in creating a Covid vaccine during the pandemic.

Arexvy generated around £1.2bn in sales in 2023, well ahead of the £699m its rival Pfizer generated with its own vaccine.