03:53 AM EDT, 05/29/2025 (MT Newswires) -- Moderna ( MRNA ) said late Wednesday its investigational pandemic H5 avian influenza vaccine showed "a rapid, potent and durable immune response" in a phase 1/2 clinical study in about 300 healthy adults.

In the study, 97.8% of participants showed immunity levels 44.5-fold higher than the baseline at day 43, or three weeks after the second vaccination, the company said.

The company said it also received a notice that the US Department of Health and Human Services will terminate the funding for late-stage development and the right to purchase its pre-pandemic influenza vaccines.

Moderna ( MRNA ) Chief Executive Stephane Bancel said that while the termination of the award "adds uncertainty" to the future of the vaccine, the company "will explore alternative paths forward for the program."

Moderna ( MRNA ) shares were up 1% in after-hours activity Wednesday.