The Biden administration announced on Wednesday that travelers from China, Hong Kong and Macau must present a negative Covid-19 test before entering the United States, a move it says is aimed at slowing the spread of the virus. spread of coronavirus. The requirement will go into effect on January 5.
The announcement by the Centers for Disease Control and Prevention comes amid growing concerns about the rise in cases in China and the country’s lack of transparency about the outbreak there.
CDC officials said the testing requirement would apply to airline passengers regardless of their nationality and immunization status. It will also apply to travelers from China entering the United States through a third country and to those connecting through the United States to other destinations.
China’s Covid outbreak is getting worse in recent days, with local authorities reporting hundreds of thousands of infections every day. Videos obtained by The New York Times show Patients crowded the hospital corridors. But the situation is very difficult to monitor in real time because of China does not publish reliable Covid data.
After three years of insisting on the “no Covid” policy, China has implemented a sudden rotation in early December and lifted that policy, after mass protests over the blockade threatened the ruling Communist Party. Since then, cases have exploded in Beijing.
Scientists in Hong Kong reported that a sub-variable Omicron called BF.7 caused the outbreak in Beijing. That variant is a subline of BA.5, which until recently dominated in the United States. But BF.7, despite being available in the US for months, still shows no sign of outperforming other versions of Omicron here.
The CDC estimates that BF.7 accounted for 4% of cases at the end of December, and it has become less common since November. Other Omicron sub-variants that scientists believe may be better at detecting evading the existing immune responses that currently prevail in the United States.
Scientists have said in recent days that, at least for now, the variant driving China’s outbreak may not necessarily be the one that most effectively overcomes immune responses. . Because very few people in China have previously been infected with versions of Omicron, any highly contagious sub-variants of Omicron that have been spreading around the world recently could have broken out there.
In a population like China with very little immunity to infections, they say, the dominant variant may not necessarily be the best variant to overcome those immune responses. which is simply the variant that catches fire.
“In a sense, whatever comes first is likely to prevail there,” said James Trauer, an expert in modeling infectious diseases at Monash University in Melbourne, Australia.
This is an evolving story. Check back for updates.
