GENEVA - The World Health Organization (WHO) cautioned on Wednesday that the more transmissible Omicron together with the currently circulating Delta variants might lead to "a tsunami of cases," putting immense pressure on national health systems. Recapping WHO's response since the onset of the COVID-19 pandemic, Director-General of WHO Tedros Adhanom Ghebreyesus said at a press briefing that he's "highly concerned that Omicron being more transmissible, circulating at the same time ...