Fauci says 'cautiously optimistic' about Covid-19 vaccine by year end

The United States is still on track to possibly have a Covid-19 vaccine by the end of year or early next year, but the nation's top infectious disease expert, Dr Anthony Fauci, warned there is still some uncertainty.

In a video message and presentation shown during a virtual panel held by the United Nations Academic Impact initiative on Wednesday, Fauci noted that many vaccine candidates currently are being studied, including the biotechnology company Moderna's mRNA vaccine, whose phase three trial was recently delayed to start later this month or in early August, reports the CNN.

Promising results so far from that vaccine candidate and some others "makes me cautiously optimistic, although you can never, ever predict with any certainty whether a vaccine is going to be safe and effective," Fauci said during the presentation.

"The early data on these trial have us have a cautious optimism that we will be successful at least in developing a vaccine with some degree of efficacy by the end of the year, beginning of 2021," he added.