The COVID-19 pandemic has reached a new grim milestone with more than 11,000 new daily deaths recorded globally for the first time this week over several days in a row, making it the deadliest week yet.

Starting on Tuesday, the daily death toll this week has surpassed 11,000 fatalities linked to COVID-19, the disease caused by the novel coronavirus. That’s according to official data the Johns Hopkins University tracks on the pandemic.

Friday’s total death toll was not yet available, but it appeared to be on track to be another ghastly day with Italy reporting 699 new deaths, Poland recording 626 new fatalities and several other countries, including Mexico, Iran, Russia and Ukraine each reporting more than 400 deaths.

With 66,009 deaths recorded between last Friday and Thursday, this has been the deadliest week yet since the World Health Organization declared the deadly novel coronavirus that emerged in China last year a pandemic in March.

And yet, these staggering daily record death tolls do not appear to be the peak. The number of new infections around the world is also rising and that will likely lead to an even greater number of daily deaths in the coming weeks.

“More cases of COVID-19 have been reported in the past four weeks than in the first six months of the pandemic,” said Tedros Adhanom Ghebreyesus, the WHO director-general, in a news briefing on Friday. “Across Europe and North America, hospitals and ICU units are filling up or full.”

Since late October, the world has detected more than 500,000 new infections every day with a new record reached on Thursday when 650,433 new confirmed cases were reported, according to Johns Hopkins data. The Baltimore university’s data corresponds to that published by the WHO, though the United Nations’ health agency’s data lags by a few days.

With deaths and infections mounting during what has been termed a second wave of the pandemic, health experts hope the global health crisis can be reined in with new vaccines, a few of which appear to be getting close to wide-scale deployment around the world.

In recent weeks, vaccines being developed in Europe, the United States, China and Russia have announced good results from advanced clinical trials that manufacturers say show their products are very effective. This week, the U.S. pharmaceutical giant Pfizer and BioNTech, a German company, said their vaccine, which uses a novel technique involving gene-editing, is highly effective in people over the age of 65, an age group considered at risk from COVID-19. On Friday, the companies applied to have their vaccine approved on an emergency basis by U.S. authorities.

“This week, there has been more good news from vaccine trials, which continues to give us hope of ending the pandemic,” Tedros said during the news briefing at the WHO headquarters in Geneva.

WHO experts also were heartened by a new British study showing that people infected by the virus had antibodies against it six months later. The study by Oxford University Hospitals was based on samples between April and November collected from 12,180 of its healthcare workers.

“This is really good news to see that we are seeing sustained levels of immune response in humans,” said Dr. Mike Ryan, the head of emergencies at WHO.

He said the study was “potentially significant news” if it proves that people who are infected build up long-lasting immunity.

“It also gives us hopes as well on the vaccine side that if we start to see similar immune responses to the vaccine, we may hope for longer periods of protection,” he added.

Maria Van Kerkhove, the WHO’s technical lead on the pandemic, said the British study backs up what other researchers are finding around the world. She said there are more than 300 studies looking at how people respond to the new virus.

She added that it is crucial to understand the virus better and she welcomed the vast trove of scientific studies into the virus. She said the virus will be better understood the longer it stays around in humans.

Despite all the research, there are many gaps in science’s understanding of how and when the virus first got into the human population. For example, earlier this week Italian researchers with Italy’s National Cancer Institute found that the virus was circulating in Italy since September 2019, a finding that backs up previous research suggesting the virus was in Italy long before clusters of infection were discovered in late February, sparking panic and marking the beginning of the pandemic.

Italian researchers said they found that 11.6% of 959 healthy volunteers who enrolled in a lung cancer screening trial between September 2019 and March 2020 had developed coronavirus antibodies.

China officially announced it detected the first cases of the virus in Wuhan, a large industrial city in central China, in late December. It’s believed the virus jumped from bats to other animals before it started infecting humans. Research has suggested it likely emerged in China a few months before the clusters of sick people were found in Wuhan.

The WHO is coordinating efforts by a team of international scientists to go to China and trace the origins of the virus. Those experts have held their first online meetings but they have not yet reported any findings.

At news briefings, the WHO has been tight-lipped about the progress of the inquiry, which has become a major political issue after President Donald Trump accused China and the WHO of covering up the origins of the virus.

The U.S. and China have both accused each other of creating the virus in bioweapons laboratories, something the vast majority of scientists reject as impossible. Scientists believe the virus is common in bats and somehow found its way into humans. Previous coronavirus outbreaks – the SARS and MERS epidemics in 2002-2004 and 2012, respectively – were traced to bats and camels. Before the pandemic, scientists warned another coronavirus might be even worse.

This novel coronavirus, scientifically known as SARS-CoV-2, has become the biggest crisis since the end of World War II, according to many experts. It has caused massive economic and political shock and killed about 1.4 million people globally.

— Courthouse News reporter Cain Burdeau is based in the European Union.