Merck (MRK) has reported a significant decline in sales of its Gardasil vaccine, which fell 39% year-over-year to $5.2 billion in 2025. This sharp decrease is primarily attributed to weakened demand in China, exacerbated by an economic slowdown, leading Merck to temporarily halt shipments of Gardasil to allow its partner, Zhifei, to reduce existing inventory levels. In addition to China, sales are also declining in Japan, with expectations of continued reduced demand in the first quarter of 2026, which is projected to generate $1.18 billion in sales for Gardasil.
Merck is experiencing broader challenges with its vaccine portfolio, as other products like ProQuad and Pneumovax 23 also reported declines. In contrast, the company’s new vaccine, Capvaxive, shows promise with expected sales growth. Furthermore, its recently approved RSV antibody, Enflonsia, posted fourth-quarter 2025 sales of $21 million but faces stiff competition from rivals such as AstraZeneca and Sanofi, whose product Beyfortus generated €284 million in sales during the same quarter.
Year-to-date, Merck’s shares have increased by 8.9%, outperforming the industry, which saw a 5.4% decline. However, the Zacks Consensus Estimate for Merck’s earnings per share for 2026 has dropped from $5.18 to $4.93 over the past 60 days, indicating potential ongoing challenges for the company.
