GSK shares fall after vaccine sales disappoint in Q3 results

GSK shares plunged up to 7% on October 28, 2026, after Q3 results revealed a 4% decline in vaccine revenue, driven by slumping demand in China for shingles shot Shingrix and a 22% drop in RSV vaccine Arexvy. CEO Luke Miels cited US vaccine hesitancy alongside seasonal factors. Overall quarterly revenue rose 4% to £8.89 billion, beating forecasts due to a 14% jump in specialty medicines, as GSK pivots to oncology and prepares for 2028 HIV patent expiries.

GSK Q3 vaccine sales decline

• ▪GSK Plc shares fell as much as 7% in London trading on October 28, 2026, after the pharmaceutical company reported a 4% year-on-year drop in third-quarter vaccine sales
• ▪GSK maintained its full-year 2026 forecast for core earnings-per-share growth of 7% to 9%, but specified results will land in the lower half of that range
• ▪GSK reported third-quarter 2026 revenue of £8.89 billion, up 4% to 5% at constant currency, beating analyst expectations despite a 4% decline in vaccine revenues
• ▪Chief Executive Officer Luke Miels is pursuing a cost-cutting plan announced earlier this year designed to generate £1.9 billion in annual savings by 2029, taking a £328 million charge in Q3 2026

Shingrix China demand weakness

• ▪GSK Chief Financial Officer Julie Brown stated that Shingrix faced a tough Q3 2026 comparison in China due to a unusually large shipment during the third quarter of the prior year
• ▪Declining demand in China for GSK's bestselling shingles treatment, Shingrix, significantly weighed on the company's vaccine division revenue in Q3 2026

Arexvy seasonal sales impact

• ▪Sales of GSK's respiratory syncytial virus (RSV) vaccine, Arexvy, dropped 22% in Q3 2026 amid lower demand in the United States
• ▪GSK Chief Executive Officer Luke Miels stated on October 28, 2026, that Arexvy sales were impacted by seasonality because RSV shots are typically administered alongside flu shots before flu season begins

US vaccine hesitancy concerns

• ▪GSK faced increased competition in the United States and delivery delays that reduced quarterly revenue from its flu vaccine lineup in Q3 2026
• ▪GSK Chief Executive Officer Luke Miels noted a broader background of softer enthusiasm and political uncertainty surrounding immunizations in the United States under Health Secretary Robert F. Kennedy Jr.

Specialty medicines revenue growth

• ▪GSK's specialty medicine business, which includes HIV and oncology drugs, grew 14% in Q3 2026, serving as the primary growth driver for the quarter
• ▪GSK is shifting operational focus toward specialty medicines and oncology to offset projected revenue losses when four key HIV drugs containing dolutegravir lose patent protection starting in 2028

Nuvalent acquisition for oncology

• ▪GSK acquired U.S. biotech company Nuvalent Inc. for $10.6 billion earlier in 2026 to expand its cancer therapy portfolio, marking its largest biotech deal to date
• ▪The $10.6 billion acquisition of Nuvalent Inc. contributed to higher annual interest charges of £700 million to £750 million for GSK in 2026