Director-General of the World Health Organisation Dr Tedros Adhanom Ghebreyesus speaks during a news conference in Geneva, Switzerland on January 30, 2020. Reuters
Director-General of the World Health Organisation Dr Tedros Adhanom Ghebreyesus speaks during a news conference in Geneva, Switzerland on January 30, 2020. Reuters

WHO: there may never be a 'silver bullet' for Covid-19