out bad behaviorafter three years of insisting on a zero covid policy china made an abrupt turnabout in early december and lifted that policy after mass protests over lockdowns that threatened the ruling communist party since then there has been a dramatic uptick in the number of cases in beijinga major concern among public health officials is that the chinese population has little natural immunity allowing the virus to spread rapidly rapid spread in turn creates new opportunities for the virus to evolve posing a risk that new variants may emerge and spread to other parts of the worldscientists say that does not necessarily mean that a more dangerous variant will soon emerge in china over the past year people in the united states have gotten infected with waves of omicron subvariants but because people in china have essentially been walled off from those versions of the virus scientists said that any of them could take off therein some sense whatever took off first is probably going to be dominant there said james wood an infectious disease expert at the university of new south wales in sydneysome past variants are believed to emerged when the virus mutated during lengthy infections in people with compromised immune systems suggesting that the amount of transmission in a given place may not on its own determine the likelihood of new variants developingwhile there is an argument that with more people being infected there may be more opportunity for mutation and the development of a new variant said jeffrey shaman an infectiousdisease modeler at columbia university we still dont know whether new variants predominantly develop during passage from person to person or within persons who experience extended infectionswatch us to require negative covid19 test for travellers from china