COVID death toll surpasses 5 million worldwide

The coronavirus is responsible for more than five million confirmed deaths around the world as of Monday, according to data from the Center for Systems Science and Engineering at Johns Hopkins University. Such a loss would wipe out almost the entire population of Melbourne, Australia, or most of the nation of Singapore.

Experts say that five million is an undercount. Many countries are unable to accurately record the number of people who have died from Covid-19, like India and African nations; experts have questioned the veracity of data from other countries, like Russia.

“All of these estimates still rely on data being available, or someone going and collecting it before antibodies and local memories wane,” said Adam Kucharski, an associate professor at the London School of Hygiene & Tropical Medicine who mathematically analyzes infectious disease outbreaks. “Globally, there will have been numerous local tragedies going unreported.”

The real number of people lost to Covid-19 could be underestimated by “a multiple of two to 10” in some nations, said Denis Nash, an epidemiologist at the City University of New York Graduate School of Public Health and Health Policy. Overall, he said, the true global toll could be as high as twice the reported figure (not up to 10 times, as an earlier version of this item incorrectly implied).

The pace of confirmed deaths seems to have slowed slightly since the world reached four million in early July, despite the rapid spread of the Delta variant since then — a sign that the spread of vaccines could be having an impact, at least in some parts of the world. It took nine months for the virus to kill one million people, three and a half more to reach two million, another three to claim three million and about two and a half to exceed four million.

The United States leads all other countries, with more than 745,000 deaths confirmed in total. The nations with the highest reported death tolls after the United States are, in order, Brazil, India, Mexico and Russia.

The global rate of reported deaths climbed over the past two weeks after trending downward for much of September and the first half of October, but at an average of over 7,000 deaths per day remains about 3,000 less than its August peak. The World Health Organization said last week in a report on pandemic conditions that confirmed deaths had increased in Europe and Southeast Asia, and declined in parts of Africa, the Middle East and Asia.

Dr. Nash said that the death rate appeared to be slowing “in places around the world where we are doing a good job at counting deaths, which also happen to be places in the world that have the best access to vaccines.”

But, he continued, “I think there are places where there are increases in the death rates, but we’re just not measuring them.”

The 20 countries that have recorded the most reported deaths per capita in recent weeks are mostly in Eastern Europe and the Caribbean, and most of them have vaccinated far less than half of their populations.

Coronavirus cases are rising in Europe, even though three-quarters of the European Union’s adult population has been fully vaccinated. Those inoculation rates plummet in countries like Bulgaria and Romania, and are even lower in nations that are outside of the bloc, like Armenia.

That vaccination gap persisted even when shots became more widely available. A September report on perceptions of the pandemic by the European Council on Foreign Relations said that the disparity seemed to be driven largely by misinformation, distrust and skepticism.

Vaccine hesitancy is also a major problem for Caribbean nations, and many of them also face unequal distribution of doses and logistical hurdles, the W.H.O. said in October.

W.H.O. officials have pressed wealthy nations to provide more vaccines to poorer ones. They and others have decried vaccine hoarding and most booster shot programs when much of the world has yet to be inoculated. Worldwide, about 76 percent of shots that have been administered have been so in high- and upper-middle-income countries, according to the Our World in Data project at the University of Oxford. Only 0.6 percent of doses have been administered in low-income countries.

Dr. Nash said he was hopeful that expanded access to vaccines and new pharmaceutical treatments, including an antiviral pill by Merck, would eventually rein in the virus.

Dr. Kucharski said that the actual number of dead would not be known for a long time.

“People need to be aware that it may take years to truly understand the toll of Covid-19,” he said.