'Pfizer And Partner BioNTech Say They Will Stop U.S. Covid-19 Vaccine Study In Healthy Adults Ages 50 To 64 Due To Slow Enrollment' - Reuters Exclusive

Pfizer and BioNTech have ceased recruitment for a U.S. trial of their updated COVID-19 vaccine targeting healthy adults aged 50 to 64 due to insufficient enrollment, which was closed on March 6. The companies aimed to enroll 25,000 to 30,000 participants but faced challenges amid tougher FDA requirements and low vaccine uptake. They clarified that the study's termination is not related to safety concerns but rather the inability to gather necessary data. Surveillance for COVID illness among participants will stop after April 3.