Shares of Merck are sliding in early trading after the drugmaker surprised Wall Street with a lower-than-expected 2025 sales forecast due partly to a pause in shipments of one of its top-selling products to China.

The continued decline of Merck & Co.’s HPV vaccine Gardasil in China has come to a head as the New Jersey drug giant is halting shipments to the world’s second-most populous country. | The recent decline of Merck & Co.

Merck said on Tuesday it would not ship its HPV vaccine Gardasil in China until at least the middle of this year due to weak discretionary spending, a move that dented its full-year forecast and sent shares tumbling over 8% in premarket trading.