Anthony Fauci, America's top infectious disease expert, has said that it was not likely for a Covid-19 vaccine to be available in the US until next year, the media reported.

He made the remarks on Wednesday during a virtual session with the editor-in-chief of the JAMA medical journal, The Hill news website reported.

Fauci said that even though companies "would have enough data for the independent safety monitoring board to recommend applying for emergency authorization" by December, the Food and Drug Administration (FDA) might not grant that authorization early next year.

The director of the National Institutes for Allergies and Infectious Diseases further said that the FDA's vaccine committee is going to want to see "good enough safety data and even prolonged efficacy data".

Regarding the wearing of masks, Fauci said adding that people should stop politicising the issue, as donning them "does make a difference".

"We have to shake each other by the collar, and say: 'Look at the data! It speaks for itself'.

"Let's put aside these extraordinary excuses for not doing it, when we're dealing with a situation that's not trivial.

"We have 225,000 deaths, the modeling tells us we're going to get one hundred or more thousand as we get into the winter, that is just something that's unacceptable," The Hill news website quoted the top expert as saying.

Fauci's remarks comes as the US is trying to battle a resurgence of fresh coronavirus cases.

Presently the worst-hit country in the world by the pandemic, the US has so far reported 8,855,182 Covid-19 cases and 227,673 deaths.