Merck Shares Under Pressure as Gardasil Sales Slump 39% on Weak China Demand

Key Facts

1Gardasil sales slumped 39% in 2025.

2The decline is primarily driven by weak demand in the Chinese market.

3Management expects no rebound in sales for the year 2026.

Merck & Co. (MRK) is facing significant financial headwinds following a sharp decline in sales for its flagship HPV vaccine, Gardasil. The company reported a 39% slump in Gardasil sales during 2025, a development that has raised concerns among investors regarding future growth. This downturn is primarily attributed to a substantial decrease in demand within the Chinese market, which remains a critical region for the product's global revenue. Compounding the issue, Merck's management has indicated that they do not anticipate a recovery in sales figures for the upcoming year of 2026. Analysts suggest that the prolonged weakness in such a key revenue driver could lead to downward revisions in earnings estimates. Consequently, the stock is expected to face continued pressure as the market digests the negative outlook for its pharmaceutical portfolio.