Seniors losing interest in vaccine trial now that more are eligible for shots

• "The window is closing on the ability to conduct a randomized trial,'' Gregory Glenn, the president of research and development at Novavax, which is enrolling a trial for a potential vaccine, told the Post.

Between the lines: One alternative to placebo-controlled trials are trials that compare an investigational drug against an existing one.

• But the Pfizer and Moderna vaccines' high rates of efficacy could make this kind of trial difficult.

The bottom line: “The future of large-scale trials [for coronavirus vaccines] is in doubt,'' Arthur Caplan, a clinical trial specialist at the New York University Langone medical center, told the Post.

• "The more vaccines appear with either emergency approval, expanded criteria or plain licensing, there's no way that people are going to sign up for trials with placebo controls."