More research needed into asymptomatic spreading of virus - WHO

''Since early February we have said that asymptomatic people can transmit COVID-19 but that we need more research to establish the extent of asymptomatic transmission, that research is ongoing and we are seeing more and more research being done,'' Ghebreyesus told an online briefing.

Some experts on Monday (June 8) questioned WHO technical lead Maria van Kerkhove's statement that transmission of COVID-19 by people with no symptoms was "very rare", saying this guidance could pose problems for governments as they seek to lift lockdowns.

Van Kerkhove, citing disease-modelling studies, clarified on Tuesday (June 9) that some people do not develop symptoms, but can still infect others.