The spread of Covid-19 in China could tell us just how deadly Omicron really is

The rapid spread of Covid-19 in China has led to reports of overcrowded hospitals and flooded crematoria. It might also help answer if Omicron is really a milder version of the virus.

Iterations of the Omicron variant are spreading rapidly in China after officials relaxed zero Covid controls in place during most of the pandemic. Pharmacies say they are out of fever medication and hospitals are strained, staff said. Chinese officials have reported a modest increase in cases and deaths from Covid-19, but some public health experts and loved ones of the deceased suspect a higher figure.

Chinese officials have told citizens that Omicron is significantly less lethal than previous variants. Some studies suggest that Omicron is milder than previous versions. In countries like the US, high numbers of omicron-related infections result in less severe disease compared to previous waves.

But Covid-19 vaccines and past infections have boosted immunity in the US and elsewhere, public health experts said, lowering the risk of hospitalizations and deaths as the pandemic progressed.

China counters the Omicron variant with lower exposure to the virus and lower vaccination rates among the elderly, public health experts said. The spread of Covid-19 there will help explain how lower rates of serious illness and death are influenced by the nature of omicron compared to a population’s built-in defenses.

“China will be very important for us to understand how Omicron works,” said Dr. Melanie Ott, who directs the Gladstone Institute of Virology at the University of California, San Francisco.

Pedestrians wearing protective gear in Beijing earlier this month.


Photo:

Bloomberg News

Tracking Omicron’s impact in China will be challenging, as too few deaths could mask its lethality and blind residents to the full danger, public health experts said. They, along with families of deceased patients, have said they believe the government is not releasing the full toll taken by the virus.

China has reported a handful of deaths since ending its control policy. His definition of what constitutes a Covid-19 death is narrow by global standards.

China relied on measures such as mass testing, lockdowns and border closures to contain the virus and limit case numbers for most of the pandemic. Covid-19 vaccination campaigns and work to strengthen health infrastructure to prepare for surges were not as much of a focus.

Now China is confronting the rest of the world the rapid spread of Omicron subvariants. Shortly after Omicron was identified in late 2021 and quickly outstripping other versions of the virus, some studies and anecdotal reports from doctors suggested it caused milder disease than its predecessor, Delta. But it was clearly more transferrable.

Research on human cells and animals like hamsters has found that Omicron may not penetrate as deeply into the lungs as its predecessors, potentially leading to less severe disease. Instead, there could be a greater impact on the upper respiratory tract, said Michael Diamond, a viral immunologist and professor of medicine at Washington University School of Medicine in St. Louis.

Antigen test kits being assembled here at a factory in China’s eastern province of Jiangsu are reportedly in short supply.


Photo:

Agence France-Presse/Getty Images

“Therefore, you could get more transmissions and less serious illnesses,” said Dr. Diamond, author of one such article. He also said the animal findings may not apply to humans.

Researchers in the US found that among hospitalized patients with no prior immunity, the risk of serious consequences was lower in patients infected with Omicron than in those infected with Delta. But Omicron’s risk in hospitalized patients was similar to previous variants, including the original strain, according to the study published in Clinical Infectious Diseases this month.

With each mutation, the Covid-19 virus becomes more transmissible. WSJ’s Daniela Hernandez discusses the science of how Covid variants are better at infecting and spreading. Picture: Rami Abukalam

Overall, Omicron is still likely less severe than previous versions of the virus, said Matt Robinson, the paper’s lead author and an assistant professor in the Department of Infectious Diseases at Johns Hopkins University School of Medicine. dr Robinson said that increases in popular immunity in the United States and elsewhere have helped increase protection against serious diseases.

Virus concentrations in US sewage are showing higher levels nationwide than two years ago, when the country’s death toll was at its peak, data from tracking company Biobot Analytics shows. But mortality has gone down. States and territories reported about 2,950 Covid-19 deaths in the most recently measured week, compared with a peak of over 23,380 in a single week in January 2021, according to the Centers for Disease Control and Prevention.

Omicron’s ability to spread so easily can still result in significant death tolls, even when individuals are at lower risk. The U.S. variant sparked the second-highest death toll in the pandemic last winter, in part due to the sheer number of people infected. Covid-19 was the third leading cause of death in the United States in both 2020 and 2021, after heart disease and cancer.

Most of China’s population has received at least one dose of vaccine, but only 66% of people over 80 are fully vaccinated and just over 40% had received a booster shot, an official with China’s Disease Control and Prevention Administration said last week. China said it was The aim is to give at least one injection to at least 90% of people aged 80 and over by the end of January.

In Hong Kong, which also had tight pandemic controls and low vaccination and booster rates among the elderly, Omicron spread widely earlier this year. At its peak, the death rate was among the highest recorded anywhere in the world during the pandemic.

“There is great concern that the Hong Kong experience will be reflected across China,” said Dr. Christopher Chiu, Professor of Infectious Diseases at Imperial College London.

Write to Brianna Abbott at [email protected] and Jon Kamp at [email protected]

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