Despite repeated claims they're committed to transparency, Johnson & Johnson and the US Food and Drug Administration still aren't revealing crucial details one week after the pharmaceutical giant's Covid-19 vaccine trial went on pause.

Public health experts have encouraged transparency in the Covid-19 vaccine clinical trials, considering that hundreds of millions of Americans will eventually be asked to roll up their sleeves and take a vaccine.

The Johnson & Johnson trial was put on hold October 12 due to a study participant's "unexplained illness," according to a company statement last week. Johnson & Johnson voluntarily stopped enrolling study participants while the illness is being reviewed by an independent monitoring board.

The company and the FDA declined to answer two questions from CNN: One, whether the study volunteer who became ill received the vaccine or the placebo, and two, if this is the first pause for the trial.