Coronavirus: 2022 ends with imminent risk of new variant, public health experts warn

CNN
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As the world enters a new year, many public health and infectious disease experts are predicting that monitoring new coronavirus variants will be an increasingly important part of Covid-19 mitigation efforts – and some are turning their attention towards an increase in cases in China.

Subvariants of the Omicron coronavirus variant continue to circulate around the world, and « we see Omicron doing what viruses do, which is picking up mutations along the way that help it to escape some immunity induced by previous infection or vaccination ». said Andrew Pekosz, a microbiologist and immunologist at the Johns Hopkins Bloomberg School of Public Health in Baltimore.

« We haven’t seen any major leaps in terms of the evolution of Omicron for some time, » he said. But « it gets to that point where it’s something we have to keep monitoring. »

In the United States, Omicron subvariants BQ.1.1, BQ.1, XBB, BA.5, BF.7 and BN.1 are responsible for almost all Covid-19 infections, according to data from the United States Centers for Disease Control and Prevention. .

Omicron’s offshoots also appear to be dominating globally, but as the coronavirus continues to spread – particularly in China following Beijing’s rapid easing of restrictions – there are now concerns about the direction the coronavirus might take. Covid-19 trends in 2023 and the risk of emergence of new variants.

« It’s a concern, » said Dr. William Schaffner, a professor in the Division of Infectious Diseases at Vanderbilt University Medical Center in Nashville and medical director of the National Foundation for Infectious Diseases. « And that, of course, led to the very recent announcement by the CDC that they’re going to require people who come to this country from China to be tested and test negative before they can enter the country. »

US health officials announced on Wednesday that starting Jan. 5, travelers from China will be required to present a negative Covid-19 test result before flying to the country. Passengers traveling to the United States from China will be required to get tested no later than two days before the flight and present proof of the negative test to their airline before boarding.

Officials also announced that the CDC is expanding the traveler-based genomic surveillance program at Seattle and Los Angeles airports, bringing the total number of participating airports to seven with approximately 500 weekly flights from at least 30 countries covered, including approximately 290 weekly flights from China and surrounding areas.

The Chinese government hasn’t shared much information about the genetic makeup of the viruses it sees there, Schaffner said.

“Because the Chinese government wasn’t doing that, that’s the main reason the CDC put in place this new travel requirement. It is certainly not to prevent the simple transmission of Covid from China here. We have a lot of Covid. It would be like telling people not to pour a bucket of water into a swimming pool,” he said. « This travel testing requirement is a way to save us time and help create a sort of buffer between us and China, should a new variant suddenly appear in that country. »

He added that the United States will need “as much time as possible” to update vaccines and antivirals to respond to a potential emerging variant of concern.

US testing requirements for travelers will « buy time », but they will not prevent new cases of Covid-19 from arriving in the United States or new variants from emerging, said Dr Carlos Del Rio, Associate Executive Dean of Emory. Grady School of Medicine and Health System in Atlanta.

« I don’t think we’re going to see a lot of upside, honestly, » he said of the travel requirements. « The most important thing that we need right now is that we need the Chinese to have more transparency and tell us exactly what’s going on, and that’s pretty much a diplomatic decision. That’s a question of diplomacy.

When it comes to publicly available genetic data on China’s coronaviruses, « it’s really a bit of a black hole, » Pekosz said. Nearly 250 million people in China may have caught Covid-19 in the first 20 days of December, according to an internal estimate from the country’s top health officials, Bloomberg News and the Financial Times reported last week.

« For me what’s really concerning are the ongoing infections and if they produce more variants in China that might be of particular concern to us, and testing people before they get on a plane won’t answer. to this question, » Pekosz said. .

« What we really need is to do a much better job of sequencing viruses from people who travel from China so that we can help understand what kinds of variants are circulating there, » he said, adding that throughout the pandemic, Chinese officials have not been very transparent about their variant data.

The constant spread of a virus is what can lead to the emergence of variants. The more a virus spreads, the more it mutates.

“For a variant to emerge – and this is true not only for Covid, but for influenza and for many other viruses – the most critical thing is that the more cases you have, the more likely it is that the virus will start to spread. ‘accumulate mutations that might have the ability to evade immunity more efficiently or transmit themselves more efficiently,’ Pekosz said.

« So when you have a situation like the one that’s starting to happen in China, where you’re going to have millions and millions of infections, each one of those infections is just another opportunity for the virus to pick up a mutation random that might make it better at infecting people, » he said. « Combine that with the fact that people in China are using less than optimal vaccines and apparently haven’t been as good at putting boosters in its population than other countries, it means that there is probably lower immunity in the population. .”

Chinese health authorities have « significantly increased » the number of coronavirus genome sequences and other related data they submit to the global database GISAID, an initiative that maintains databases allowing scientists around the world to share flu virus and coronavirus data.

But many experts say that’s not enough.

GISAID said in an email to CNN on Wednesday that the Chinese Center for Disease Control and Prevention and several regional centers in the country « have significantly increased the number of submissions of genomic sequences and associated metadata from collected samples. the last days ».

The GISAID Data Science Initiative announced that it has released genome sequence data from 167 SARS-CoV-2 samples collected during the current outbreak in China. SARS-CoV-2 is the name of the virus that causes Covid-19. GISAID also confirmed that the sequences from China « all closely resemble known variants circulating globally observed in different parts of the world between July and December 2022 », compared to the 14.4 million genomes in the GISAID database. GISAID.

« These latest data provide a snapshot of the evolution of Omicron variants and show that these most recently shared sequences from China are closely related to variants that have been circulating for some time, » according to the GISAID Data Science Initiative.

Covid-19 is currently in a relatively ‘stable’ state in the United States, but the nation still sees about 350 disease-related deaths every day, said Dr. Jessica Justman, associate professor of medicine in epidemiology at Columbia University. Mailman School of Public Health and Senior Technical Director of the ICAP Global Health Program.

As Covid-19 levels remain well below those of previous surges, trends are on the rise in parts of the US, new hospital admissions jumped nearly 50% in the month last, and there are growing fears that the number of cases will skyrocket after the winter holidays.

To reduce the risk of further spread of Covid-19, Justman said, it will be important for people in the New Year to continue keeping up to date with their Covid-19 vaccinations.

According to CDC data, only 14.6% of the US population ages 5 and older received their updated booster dose.

“So where are we going? This brings me to China,” Justman said.

“I fear that China is currently a giant incubator of SARS-CoV-2. There is the potential to have so many infections and with that new variants,” she said.

« I think we’re going to be looking at new variants of concern » in 2023, Justman said. “The question is, are we going to return to a point where we have a concerning variant that causes disease so severe that we do not benefit from our protection against previous infections and previous vaccinations? … I’m going to be optimistic and say I don’t think we’re going to get back to that point.