Many countries around the world are dealing with their worst coronavirus outbreaks yet .
世界上许多国家正在经历迄今为止最严重的新冠疫情暴发。
But one country , Japan , is seeing very few COVID-19 infections .
但有一个国家——日本——新冠感染病例却非常少。
Observers are trying to learn why .
观察人士正试图弄清原因。
As recently as late summer , Japan's coronavirus situation was not good .
就在夏末，日本的新冠疫情形势还不乐观。
Deaths linked to COVID-19 were being reported each day .
每天都有与新冠相关的死亡病例报告。
Hospitals were filled with coronavirus patients .
医院里挤满了新冠患者。
In September , Japan sped up its vaccination campaign .
9月，日本加快了疫苗接种工作。
The country saw a large drop in the number of reported cases .
全国报告的病例数大幅下降。
The number of deaths also sharply decreased .
死亡人数也急剧下降。
Since then , the situation has continued to improve .
从那以后，情况持续好转。
In December , Japan has reported an average of less than one COVID-19 death a day .
12月，日本平均每天报告的新冠死亡病例不到一例。
That is a shockingly low number for a country of 126 million people .
对一个拥有1.26亿人口的国家来说，这个数字低得惊人。
No one knows exactly why Japan has experienced such success .
没有人确切知道日本为何如此成功。
There are many possible explanations .
可能的解释有很多。
Nearly 80 percent of Japan's population is fully vaccinated .
日本近80%的人口已完成全程疫苗接种。
Nearly everyone wears masks .
几乎人人都戴口罩。
And , even after the government ended some restrictions this autumn , people continued to socially distance themselves .
即使政府今年秋天取消了一些限制措施，人们仍继续保持社交距离。
Some researchers have pointed to Japan's low rates of obesity .
一些研究人员指出了日本的低肥胖率。
Several recent studies have found that COVID-19 is more severe in overweight individuals .
最近的几项研究发现，超重人群感染新冠后病情更严重。
Cultural customs may also play a part .
文化习俗可能也起了作用。
For example , Japanese do not generally kiss , hug , or even shake hands when they meet .
例如，日本人见面时一般不亲吻、不拥抱，甚至不握手。
Many Japanese are also quiet in public settings , notes Kentaro Iwata .
岩田健太郎指出，许多日本人在公共场合也很安静。
He is an infectious disease specialist at Japan's Kobe University .
他是日本神户大学的传染病专家。
“Masking and keeping silent in public places is very important [for fighting the virus ].
“在公共场所戴口罩、保持安静（对抗击病毒）非常重要。
Those reasons , however , do not explain why nearby South Korea is dealing with its worst COVID-19 outbreak yet .
然而，这些原因无法解释为什么邻国韩国正在经历迄今为止最严重的新冠疫情。
South Korea shares many of the same cultural customs .
韩国也有许多相同的文化习俗。
Another possible explanation is that Japan is testing fewer people than other countries , said Kenji Shibuya .
涩谷健司说，另一种可能的解释是日本的检测人数比其他国家少。
He is an epidemiologist and researcher at the Tokyo Foundation for Policy Research .
他是东京财团政策研究所的流行病学家和研究员。
In the first half of December , Japan tested an average of 44,623 people a day , according to government data .
据政府数据，12月上半月日本平均每天检测44623人。
Because of Japan's lack of testing , it is difficult to believe that official case numbers represent reality , Shibuya told VOA in an email .
涩谷在给美国之音的电子邮件中说，由于日本检测不足，很难相信官方病例数反映了真实情况。
However , if a lack of testing were the reason , Japan would have likely seen a rise in the number of hospitalizations or deaths .
然而，如果原因是检测不足，日本的住院人数或死亡人数很可能会上升。
Because there is not any clear explanation , some researchers have tried to search for a so-called X-factor .
由于没有明确的解释，一些研究人员试图寻找所谓的“X因素”。
One study even suggested many Japanese people share a genetic feature linked to white blood cells that helps fight against COVID-19 .
一项研究甚至提出，许多日本人具有一种与白细胞有关、有助于抵抗新冠的共同遗传特征。
Others think that the coronavirus version spreading in Japan may have changed itself so much it is disappearing .
还有人认为，在日本传播的新冠病毒变种可能已经自我变异到正在消失的程度。
But , the battle is not over , said Shibuya .
但涩谷说，这场战斗还没有结束。
He said he still expects the country to see a winter wave of infections .
他说，他仍然预计日本会出现冬季感染潮。
Japan identified its first cases of community spread of the omicron version of the virus .
日本发现了首批奥密克戎变种的社区传播病例。
Scientists have said omicron spreads much faster than any earlier version of the virus .
科学家说，奥密克戎的传播速度比此前任何一种变种都快得多。
Officials say many of those found to be infected with omicron in Japan have no recent history of foreign travel .
官员说，日本发现的许多奥密克戎感染者近期都没有出国旅行史。