Merck & Co.’s blockbuster vaccine Gardasil has had a roller-coaster ride in China. A post-Covid surge in demand for the cancer-preventing shot quickly deflated last year, to the point the US pharmaceutical giant made the call earlier this week to halt shipments.

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.

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.