As China faces an increase in Covid-19 contamination, there are concerns about the emergence of new variants and subvariants. As authorities announced the end of mandatory quarantine upon arrival in the country on Monday, could this surge mark a turning point for the pandemic beyond China’s borders?
It was the last remnant of China’s “zero Covid” policy. After most of the strict health restrictions in place in the country since 2020 were lifted on December 7, health authorities announced on Monday December 26 the end of mandatory quarantine upon arrival in their territories. From January 8th, only a negative test within 48 hours will suffice.
The announcement immediately sparked tears of joy in the country, with many Chinese rushing to book flights abroad. But while the country has also been facing a massive outbreak of contamination for several weeks, this announcement sparks concern abroad and raises the question: Could this wave of Covid-19 have health implications beyond China’s borders?
The variant BF.7 singled out
According to several American media outlets, including The Financial Times, which quote the deputy director of the China Center for Disease Control and Prevention, 250 million people, or 18% of the total population, have been infected in China since December 1. A figure that is not officially confirmed and impossible to verify – local health authorities have put an end to systematic screening tests and the publication of figures on the pandemic – but which, together with the numerous testimonies reporting overwhelmed hospitals and crematoria, confirm the magnitude of this wave of contamination.
To explain this situation, specialists cite several factors. First, a large proportion of the population has never encountered Covid-19 and is not naturally immune to it. Then “the elderly and vulnerable population is little or badly vaccinated: 60% of those over 80 would have received only two doses or less,” explains Antoine Flahault, an epidemiologist at the University of Geneva. However, several studies show that Chinese vaccines, which are used exclusively across the country, are only effective from three doses.
The epidemiologist adds another parameter to this. “Subvariant BF.7, descendant of Omicron, would be the main contributor to this wave”. And this one, first discovered in Belgium last May and then also sighted in France, the United States, Great Britain or even Germany, would be particularly contagious.
“BF.7 would have an R0 (reproduction rate of the virus) of 10 to 18.6. In other words, an infected person transmits the virus to 10 to 18.6 other people on average, compared to Omicron’s average of 5.08,” he explains a highly transmissible strain of the virus.”
Currently, BF.7 accounts for only 0.99% of sequencing in France and 1.5% of infections in the United States, according to the Cov-Spectrum tool. “This number could even increase,” confirms Mircea Sofonea, lecturer in epidemiology at the University of Montpellier. “But that’s not so worrying. Europe has already experienced several waves of Omicron-related Covid-19 and we are better immunized. We have now decided to live with it.”
The fear of new variants
For the two specialists, it is therefore not primarily about BF.7, but about the emergence of a new variant from this epidemic outbreak in China. “Each infection offers the virus the opportunity to mutate and thus the possibility for a subvariant or variant of SARS-Cov2 to appear,” recalls Mircea Sofonea. “We have to prepare for it,” says Antoine Flahault, “the risk is obvious given that the virus is circulating in a country of 1.4 billion people and in a population with low immunity.”
“In the short term, the most likely hypothesis is that if a subvariant emerges, it is a derivative of Omicron,” Mircea Sofonea continues. “Like BF.7, it would only add to those already in existence and certainly would not pose any real threat to the well-immunized Western population.”
“The real fear is that a distant variant of Omicron will emerge that eludes our immunity, natural and vaccine-containing,” he warns. As a reminder, for a new variant to catch on, it must be more contagious than its predecessor, as was the case with Omicron vs. Delta, or it must evade popular immunity.
Especially since, if experts agree that the peak of contamination in Beijing may already have passed, it will take several months for the situation across the country to normalize. “China must expect to experience several consecutive waves, as was the case in western countries,” continues Antoine Flahault. “In any case, the emergence of new, more easily transmissible and possibly more virulent variants outside of what is happening in China must remain a major concern everywhere and justify our not completely lowering our vigilance,” he stresses.
In addition, alongside this threat, the health situation will certainly have economic repercussions with a slowdown in production chains in the country that is the world’s factory, as was already the case in 2020. More worryingly, although authorities have announced the requisition of production from certain pharmaceutical companies, it could also exacerbate the drug shortages hitting several Western countries this winter. In 2020, the country concentrated 50% of the world production of paracetamol.
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introduce border controls?
Amid concerns raised by the reopening of China’s borders, neighboring countries India and Japan have already decided to impose tests on travelers arriving on their territories from China. The United States “is considering taking similar action,” officials said. A measure that Antoine Flahault also advocates in Europe. “The entire Schengen area would do well to quickly reintroduce health checks to test and sequence the viruses identified in all travelers from China. This is the only way we can observe the arrival of these new variants that we fear at an early stage. And that would allow us to better anticipate the actions to be taken eventually,” he stresses.
For his part, Mircea Sofonea calls above all for the continued use of barrier gestures. “We must not forget that the Chinese are the first victims of this situation,” he concludes. “The zero Covid strategy was untenable and today they are paying for its sudden and ill-prepared repeal. Your government must act quickly to avoid a health catastrophe.”