?A terrible tragedy?: US passes 800,000 Covid deaths ? highest in the world

The US death toll from Covid-19 has passed 800,000, a once-unimaginable figure seen as doubly tragic given that more than 200,000 of those lives were lost after vaccines became available last spring.

The figure represents the highest reported toll of any country in the world, and is likely even higher.

The US accounts for approximately 4% of the world's population but about 15% of the 5.3 million known deaths from the coronavirus since the outbreak began in China two years ago.

The grim milestone comes as the world braces for rise in cases of the new Omicron variant, with the World Health Organization (WHO) warning it was spreading at an unprecedented rate.

WHO chief Tedros Adhanom Ghebreyesus told reporters on Tuesday the variant had been detected in 77 countries and was probably present in most countries worldwide.

Omicron, first detected by South Africa and reported to the WHO on 24 November, has a large number of mutations, which has concerned scientists. The new variant is posing a fresh threat as it gains a foothold in the US, though experts are not yet sure how dangerous it is.

The number of Covid deaths in the US, compiled and released by Johns Hopkins University on Tuesday, is about equal to the population of Atlanta and St Louis combined, or Minneapolis and Cleveland put together. It is roughly equivalent to how many Americans die each year from heart disease or stroke.

A closely watched forecasting model from the University of Washington projects a total of over 880,000 reported deaths in the US by 1 March.

The deadly milestone comes as cases and hospitalisations are on the rise again in the US, a spike driven by the highly contagious Delta variant, which arrived in the first half of 2021 and now accounts for nearly all infections. I

Health experts lament that many of the deaths in the US were especially heartbreaking because the widely available and effective vaccines made them preventable.

About 200 million Americans are fully vaccinated, or just over 60% of the population. That is well short of what scientists say is needed to keep the virus in check.

"Almost all the people dying are now dying preventable deaths," said Dr Chris Beyrer, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health. "And that's because they're not immunized."

When the vaccine was first rolled out, the country's death toll stood at about 300,000. It hit 600,000 in mid-June and 700,000 on 1 October.

Beyrer recalled that in March or April 2020, one of the worst-case scenarios projected upwards of 240,000 American deaths.

"And I saw that number, and I thought that is incredible - 240,000 American deaths?" he said.

"And we're now past three times that number." He added: "And I think it's fair to say that we're still not out of the woods."