Pfizer is ending its study of updated COVID-19 vaccines after Americans refused to participate in their trials. According to a report from Reuters, Pfizer and BioNTech paused the development, saying trial participation was too low for the data needed.
In a letter to trial investigators, Pfizer said it would stop surveillance for the vaccine after April 3. The enrollment for the trial was between 25,000 to 30,000 people, adults aged between 50-64.
“This is a very difficult population to recruit,” said an executive an at organization involved in the trial. “Even when patients are willing to participate in COVID studies, more than 80% fail at pre-screening because they don’t meet the health criteria. It’s been a real challenge to enroll enough patients, particularly given the scale of these trials.”
“This study is not ending as a result of any safety or benefit-risk concerns. We intend to stop the study due to slow enrollment and therefore the inability to generate relevant post-marketing data,” the companies said.
Moderna is conducting a similar study, aiming to enroll 30,000 people. Its trial is also seeing recruitment struggles.
Pfizer is also pushing a Lyme disease vaccine, although it did not meet the target in a clinical trial. According to the companies, the “fact that the 95% confidence interval lower bound was above 20 in the second pre-specified analysis” gave Pfizer confidence in the inoculation.
Thomas Lingelbach, CEO and Board member of Valneva, which partnered with Pfizer on the vaccine, said the results “bring us a step closer to our goal of delivering a much-needed vaccine to help protect against Lyme disease. We are grateful to our partner Pfizer for their strong commitment which we both share in developing this vaccine as quickly as possible.”
