Many countries around the world are dealing with their worst coronavirus outbreaks yet .
世界上許多國家正在經歷迄今為止最嚴重的新冠疫情爆發。
But one country , Japan , is seeing very few COVID-19 infections .
但有一個國家——日本——新冠感染病例卻非常少。
Observers are trying to learn why .
觀察人士正試圖弄清原因。
As recently as late summer , Japan's coronavirus situation was not good .
就在夏末，日本的新冠疫情形勢還不樂觀。
Deaths linked to COVID-19 were being reported each day .
每天都有與新冠相關的死亡病例報告。
Hospitals were filled with coronavirus patients .
醫院裡擠滿了新冠患者。
In September , Japan sped up its vaccination campaign .
9月，日本加快了疫苗接種工作。
The country saw a large drop in the number of reported cases .
全國通報的病例數大幅下降。
The number of deaths also sharply decreased .
死亡人數也急劇下降。
Since then , the situation has continued to improve .
從那以後，情況持續好轉。
In December , Japan has reported an average of less than one COVID-19 death a day .
12月，日本平均每天通報的新冠死亡病例不到一例。
That is a shockingly low number for a country of 126 million people .
對一個擁有1.26億人口的國家來說，這個數字低得驚人。
No one knows exactly why Japan has experienced such success .
沒有人確切知道日本為何如此成功。
There are many possible explanations .
可能的解釋有很多。
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種。
Nearly everyone wears masks .
幾乎人人都戴口罩。
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，人們仍繼續保持社交距離。
Some researchers have pointed to Japan's low rates of obesity .
一些研究人員指出了日本的低肥胖率。
Several recent studies have found that COVID-19 is more severe in overweight individuals .
最近的幾項研究發現，超重人群感染新冠後病情更嚴重。
Cultural customs may also play a part .
文化習俗可能也起了作用。
For example , Japanese do not generally kiss , hug , or even shake hands when they meet .
例如，日本人見面時一般不親吻、不擁抱，甚至不握手。
Many Japanese are also quiet in public settings , notes Kentaro Iwata .
岩田健太郎指出，許多日本人在公共場合也很安靜。
He is an infectious disease specialist at Japan's Kobe University .
他是日本神戶大學的傳染病專家。
“Masking and keeping silent in public places is very important [for fighting the virus ].
「在公共場所戴口罩、保持安靜（對抗擊病毒）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，這些原因無法解釋為什麼鄰國韓國正在經歷迄今為止最嚴重的新冠疫情。
South Korea shares many of the same cultural customs .
韓國也有許多相同的文化習俗。
Another possible explanation is that Japan is testing fewer people than other countries , said Kenji Shibuya .
澀谷健司說，另一種可能的解釋是日本的檢測人數比其他國家少。
He is an epidemiologist and researcher at the Tokyo Foundation for Policy Research .
他是東京財團政策研究所的流行病學家和研究員。
In the first half of December , Japan tested an average of 44,623 people a day , according to government data .
據政府資料，12月上半月日本平均每天檢測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 .
澀谷在給美國之音的電子郵件中說，由於日本檢測不足，很難相信官方病例數反映了真實情況。
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，如果原因是檢測不足，日本的住院人數或死亡人數很可能會上升。
Because there is not any clear explanation , some researchers have tried to search for a so-called X-factor .
由於沒有明確的解釋，一些研究人員試圖尋找所謂的「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 .
一項研究甚至提出，許多日本人具有一種與白血球有關、有助於抵抗新冠的共同遺傳特徵。
Others think that the coronavirus version spreading in Japan may have changed itself so much it is disappearing .
還有人認為，在日本傳播的新冠病毒變種可能已經自我變異到正在消失的程度。
But , the battle is not over , said Shibuya .
但澀谷說，這場戰鬥還沒有結束。
He said he still expects the country to see a winter wave of infections .
他說，他仍然預計日本會出現冬季感染潮。
Japan identified its first cases of community spread of the omicron version of the virus .
日本發現了首批Omicron變種的社區傳播病例。
Scientists have said omicron spreads much faster than any earlier version of the virus .
科學家說，Omicron的傳播速度比此前任何一種變種都快得多。
Officials say many of those found to be infected with omicron in Japan have no recent history of foreign travel .
官員說，日本發現的許多Omicron感染者近期都沒有出國旅行史。