WHO warns of 'tsunami' of cases from Delta and Omicron variants

NEW YORK • The World Health Organisation (WHO) has warned that continued circulation of the Delta variant and the emergence and rapid spread of Omicron could create a "tsunami" of coronavirus infections that overwhelm healthcare systems globally.

Wednesday's warning came even as top US health officials stressed that early data showed Omicron infections produced milder illness.

The global number of daily new cases crossed one million for the third consecutive day on Wednesday, according to data from Johns Hopkins University (JHU). A Straits Times tally based on the JHU data indicated that the average number of cases worldwide in the seven days up to Wednesday was 1,047,995, far higher than the levels seen in previous waves in the pandemic.

"Delta and Omicron are now twin threats driving up cases to record numbers, leading to spikes in hospitalisation and deaths," WHO director-general Tedros Adhanom Ghebreyesus said at a news conference in Geneva. "I am highly concerned that Omicron, being highly transmissible and spreading at the same time as Delta, is leading to a tsunami of cases."

But along with the warnings, US officials and the leading scientists at the UN agency said that early data offered some positive signs.

Dr Rochelle Walensky, the US Centres for Disease Control and Prevention (CDC) director, said at a White House news conference that even as cases had risen some 60 per cent over the past week to 240,000 cases a day, hospital admissions and deaths were hinting at a milder wave of the virus.

"While our cases have substantially increased from last week, hospitalisations and deaths remain comparatively low right now," she said, pointing to a seven-day average of US hospitalisations at 9,000 a day, a 14 per cent jump from last week. The seven-day average of daily deaths stood at roughly 1,100 per day, a drop of about 7 per cent.

"This could be due to the fact that hospitalisations tend to lag behind cases by about two weeks," she said, but added this may also be in line with early indications from other countries like South Africa and Britain of milder symptoms from Omicron, especially among the vaccinated and people who had received booster shots.

Citing a series of international studies, top US infectious diseases expert Anthony Fauci said that "the pattern and disparity between cases and hospitalisations strongly suggest that there will be a lower hospitalisation-to-case ratio when the situation becomes more clear".

Dr Soumya Swaminathan, chief scientific officer for the WHO, warned that evidence on Omicron is just emerging. While vaccinated people are being infected with Omicron, the early evidence on the protection that vaccinations provide was positive, she said.

Vaccines still "appeared to be protective" against severe illness and death, she said, but it was a complicated equation that needed to take into account a host of factors, including the clinical vulnerability of those being infected.

Dr Mike Ryan, the head of the WHO emergencies programme, said that Omicron had yet to work its way into all parts of society - including the most vulnerable populations and the unvaccinated.

The Omicron outbreaks around the world, he said, started in primarily younger age groups, and the variant is only now moving into older populations.

"I think we will still see decoupling from cases and severe disease," he said. But the sheer number of daily cases could lead to a surge in patients and increased pressure on healthcare systems.

He also noted that even in countries with plentiful vaccine supply, there were large pockets of unvaccinated people and it was simply too early to know if Omicron is less virulent than other variants.

Dr Tedros said the "narrative going on right now that it is milder or less severe" might be dangerous since high transmission rates alone could lead to more hospitalisations and death. "We should not undermine the bad news with the good news," he said. "There are both elements here."

NYTIMES