LONDON, March 18, 2026, 17:52 GMT
GSK’s London-listed shares closed about 2% lower on Wednesday at roughly 1,973 pence, a steeper fall than the wider market. Its U.S.-listed shares were down about 1.9% at $52.42 in afternoon trade, as European healthcare stocks sold off. 1
That matters because GSK had staged a strong recovery against several European pharma peers after a bruising 2025, helped by Luke Miels’ appointment, earnings momentum and growth in specialty medicines, Reuters reported in February. Wednesday’s close left the stock about 14% below its Feb. 18 52-week high of 2,282 pence. 2
The wider market was not helping. European healthcare stocks fell 2% after an attack on Iran’s Pars gas field rekindled fears of a broader Middle East escalation and pushed oil prices higher; the FTSE 100 finished down 0.94% at 10,305.29. 3
A company filing showed GSK repurchased 732,112 ordinary shares on March 17 at an average 2,016.45 pence under its existing share buyback, in which a company buys back its own stock. Since Feb. 17, it has repurchased more than 11.28 million shares. 4
Vaccines remain central to the story. Last week the U.S. Food and Drug Administration expanded approval of Arexvy, GSK’s shot against RSV, or respiratory syncytial virus, a common respiratory infection that can turn serious in vulnerable adults, to people aged 18 to 49 who are at higher risk of severe disease. 5
That opens a wider market, though GSK still needs a recommendation from the U.S. Centers for Disease Control and Prevention before the shot can be used in that age group. In RSV vaccines, GSK will be up against Moderna’s mRESVIA and Pfizer’s Abrysvo. 5
In the company’s statement, Sanjay Gurunathan, head of vaccines and infectious diseases research and development, said the age expansion could meet a “significant medical need” in higher-risk adults. Miels said in February that GSK needed to “accelerate” and add to its pipeline through “smart business development”, while Sheena Berry at Quilter Cheviot called his early pitch a “steady and credible start”.
There was also fresh movement in Washington. A U.S. judge on Monday blocked key parts of Health Secretary Robert F. Kennedy Jr.’s overhaul of childhood vaccine policy and halted most of his new vaccine-panel appointees, a decision Reuters said had helped U.S.-listed GSK shares close marginally higher that day alongside other vaccine makers. 6
But the relief looks fragile. Reuters reported in February that GSK expected 2026 sales from vaccines and general medicines to be flat or down low single digits and had already flagged uncertainty around its U.S. vaccine business; the administration is likely to appeal the ruling, and some public health specialists think the trust damage may last. “The genie is out of the bottle,” Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy, told Reuters. 2
