LONDON, March 18, 2026, 17:52 GMT
GSK shares in London finished Wednesday down nearly 2%, slipping to around 1,973 pence—worse than the broader market drop. Over in the U.S., the stock traded lower by about 1.9% at $52.42 during the afternoon, with European healthcare names broadly under pressure.
The point is, GSK had bounced back sharply from a rough 2025, outpacing a number of European pharma rivals, with Luke Miels stepping in, earnings beating expectations, and specialty medicines driving growth, Reuters noted back in February. By Wednesday’s close, shares were sitting roughly 14% under their Feb. 18 52-week high of 2,282 pence.
The broader market offered little relief. European healthcare shares slid 2% following an attack on Iran’s Pars gas field, stoking fresh concerns about a wider Middle East conflict and sending oil prices up. The FTSE 100 dropped 0.94% to 10,305.29.
GSK bought back 732,112 ordinary shares on March 17, paying an average price of 2,016.45 pence, according to a filing tied to its ongoing buyback program. The company has scooped up over 11.28 million shares since Feb. 17.
Vaccines are still playing a key role. The U.S. Food and Drug Administration last week broadened approval for Arexvy, GSK’s RSV vaccine, giving the green light for use in adults 18 to 49 who face higher risks of severe illness from respiratory syncytial virus, a common respiratory bug that can get dangerous for some.
That expands the market, but GSK still has to secure a nod from the U.S. Centers for Disease Control and Prevention before the shot is cleared for this age group. When it comes to RSV vaccines, GSK faces competition from Moderna’s mRESVIA and Pfizer’s Abrysvo.
Sanjay Gurunathan, who leads vaccines and infectious diseases R&D, pointed to a “significant medical need” for the age expansion among higher-risk adults, according to the company’s statement. Back in February, Miels talked up the need to “accelerate” and bulk up GSK’s pipeline with “smart business development”. Sheena Berry of Quilter Cheviot described his early approach as a “steady and credible start”.
Washington threw up its own twists Monday. A federal judge blocked significant elements of Health Secretary Robert F. Kennedy Jr.’s push to revamp childhood vaccine rules, putting a stop to most of his newly chosen vaccine-panel members. The move, according to Reuters, nudged GSK’s U.S.-listed shares up slightly, with other vaccine stocks showing similar gains.
Still, any relief comes with strings attached. Back in February, Reuters reported GSK was bracing for 2026 vaccine and general medicine sales that could be flat or even slip a little. Uncertainty in the U.S. vaccine division was already flagged. The company faces a likely appeal, and some public health experts warn trust damage could linger. “The genie is out of the bottle,” said Michael Osterholm, who heads the University of Minnesota’s Center for Infectious Disease Research and Policy, speaking to Reuters. Reuters
