The leading U.S. infectious disease expert is warning the coronavirus outbreak the world is experiencing maybe a cyclical occurrence and could return even stronger if the proper precautions are not taken.

Speaking late Wednesday during the daily White House coronavirus briefing, U.S. National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci said cases of the virus are starting to appear in South Africa and other southern hemisphere countries where winter is coming.

He said if a substantial outbreak occurs in those areas, it would be a strong indication that the virus could become cyclical and countries in the northern hemisphere should be prepared for a second round of the virus next year.

Fauci said that puts greater emphasis on the need to continue working on a vaccine that can readily available if that second round of coronavirus comes, as well as a menu of drugs that can be effective and safe in treating patients who get it.