Sanofi Suspends Flu Vaccine In China Due To Potency Concerns

Sanofi has temporarily paused the distribution and sale of its flu vaccines in China due to concerns about reduced effectiveness. A representative from Sanofi confirmed this decision to Fierce Pharma. The suspension affects the company’s two flu vaccine brands approved for use in China—Vaxigrip and VaxigripTetra—for the 2024-25 influenza season. This action follows the detection of decreased potency in the vaccines during a routine quality check of doses that were manufactured but not yet distributed, according to the Sanofi spokesperson.

The spokesperson, said in a statement, “We believe the efficacy could possibly be impacted before the end of the product’s shelf life for one of the antigens in the vaccine. The Vaxigrip and VaxigripTetra shots Sanofi manufactures have met good manufacturing practices and Chinese standards, and “the decision to stop their supply and sale is a preventive measure. All vaccines already distributed meet the necessary specifications for release and are both safe and effective.”

Sanofi has identified “unforeseen issues” at its influenza vaccine production facility in Shenzhen, China, as the cause of the problem. A company representative noted that this issue is localized to the Shenzhen plant, which supplies flu vaccines solely for the Chinese market. In contrast, in the United States, Sanofi continues to provide flu vaccines through its Fluzone, Fluzone High-Dose, and Flublok brands.

Sanofi anticipates that the current issue will not significantly affect flu protection levels in China. In 2023, the company recorded global sales of flu vaccines totaling 2.67 billion euros, reflecting a 5.5% decline from the previous year at constant exchange rates. Although Sanofi is a leading global vaccine producer, the Chinese market for flu shots is largely controlled by domestic companies. This disruption follows recent price reductions that have heightened competition among flu vaccine manufacturers in China. Since flu vaccines are not part of China’s national immunization program, individuals must pay for them privately.

Following a 31% price cut by state-owned Sinopharm on its quadrivalent flu vaccine, reducing the cost to 88 Chinese yuan (approximately $12) per dose in May, Hualan Biological Vaccine, which is the leading supplier of flu shots in China by a significant margin, and Sinovac matched this pricing reduction in June. Sanofi’s VaxigripTetra, a quadrivalent flu vaccine, faces direct competition from these local products. For the 2024-25 flu season, the U.S. is shifting to trivalent flu vaccines instead of the broader quadrivalent options. This decision comes after the FDA reported that the B/Yamagata strain of the influenza virus has not been detected globally since March 2020.

The company spokesperson said, “Sanofi remains dedicated to supporting flu prevention in China, a commitment that has guided our efforts for nearly three decades. We will continue to collaborate with our partners to ensure that influenza vaccines are available for the 2025-2026 season, protecting the health of Chinese population.”