- The World Health Organization reported record numbers of cases of Covid-19 globally for a single week amid the omicron surge.
- A report from the WHO published Tuesday noted that the highest numbers of new cases over the week came from the U.S., with 4.6 million new cases.
- But hospitalizations are lower than in previous surges, though the death rate remains unsustainably high.
A record 15 million new Covid-19 infections were reported across the globe in a single week as omicron rapidly replaces delta as the dominant variant across the globe, and "we know this is an underestimate," World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus told reporters at a press briefing Wednesday.
"The sheer volume of cases is putting a burden on health-care systems," said Maria Van Kerkhove, WHO's technical lead on Covid-19. "Even though omicron is less severe than delta, it is still putting people in the hospital. It is still putting people into ICU and needing advanced clinical care. It is still killing people."
The U.S. saw the biggest jump in cases with 4.6 million new infections reported for the week through Sunday, a 73% increase over the prior week, compared to a 55% global increase in cases over the same period, according to a the WHO's weekly epidemiology report published Tuesday.
Tedros noted that hospitalizations are not quite as high as seen in previous surges, possibly due to decreased severity of omicron compared to delta and widespread immunity from vaccines and prior infection. But, he added, the death rate is still unsustainably high, with an average of about 48,000 deaths per week, which hasn't fluctuated much since October, Tedros said.
"We're seeing omicron out-compete delta in many populations," Van Kerkhove said. While delta cases similarly peaked in a few months, it didn't take over the globe as quickly nor were the cases as high as omicron. "This is off the charts," she said.
Among more than 357,000 cases sequenced in the last 30 days, nearly 59% were omicron, the WHO said in the epidemiological report. The WHO, the United Nations' health organization, cautioned that the data may not fully show how far omicron has spread due to reporting delays and limits sequencing in some countries.
According to the report, omicron has a shorter doubling time than other variants, meaning the number of days it takes for cases to double, and it can more readily evade prior immunity, allowing it an advantage over other variants.
While omicron has appeared to rip through populations where it was detected early and then drop down to lower levels, Van Kerkhove said delta had a similar trajectory at its height, but never peaked at such levels as omicron.
But, she emphasized, the direction of omicron can still be influenced by the world's actions, including vaccination and taking steps to minimize spread.
"There is no inevitability about this virus and how it circulates," she said. "We have control, some measure of control, in terms of limiting its spread with tools that we have access to: masks, distancing, ventilation, avoiding crowds."
Van Kerkhove said the WHO expects the virus will continue to evolve to become more fit and either more or less severe, that there will continue to be outbreaks of disease among the unvaccinated and that as different populations mix, outbreaks of other viruses will sometimes occur at the same time as those of Covid.
"The virus is well on its way to becoming endemic," Van Kerkhove said. "But we'
re not there yet."
WATCH: World Health Organization warns of Covid 'tsunami' from delta and omicron variants