中新网北京8月20日电(蒋鲤)近日，美国农业部对本国白尾鹿血液样本进行检测发现，2019年的鹿血样本中有1例携带了新冠病毒抗体，这意味着，早在2019年，美国白尾鹿族群内就已出现了新冠病毒感染。这一发现无疑将新冠病毒全球溯源工作向前推进了一大步。

研究还发现，今年1至3月在美国东北部采集到的385个白尾鹿血液样本中，约40%验出抗体。这说明，北美大陆常见的野生动物白尾鹿已大规模感染新冠病毒，但美国农业部声称没有找到原因。

美国农业部认为，2019年的样本里只有一个阳性，因此很可能是“假阳性”，但这一结论显然站不住脚。其研究方法使用的是极为精准的中和抗体检测技术，并且采取了两种技术进行双重检测，相互印证的结果是抗体仍旧显示阳性。

科学技术是检验病毒最可靠的手段。然而，尽管美国农业部对外公布了这一调查结果，但一直“叫嚷”着要求进行新冠病毒溯源的部分政客和媒体，无一例外地对此选择了“闭嘴”和“无视”，这又是为什么呢？

显然，这一调查结果将会推翻美国一直别有用心炒作的针对武汉实验室的有罪推定式调查。同时，也会阻碍美国将新冠溯源政治化以嫁祸中国的图谋。

事实上，5月10日，美国农业部传染病研究专家米切尔?帕尔默团队就在《病毒学》发表论文称，目前的证据表明新冠病毒可能从动物宿主传染给人类，而白尾鹿与人类在新冠病毒受体方面高度同源，因此，新冠病毒很可能通过中间动物宿主(例如白尾鹿)传给人类。这一发现支持将野生鹿科动物纳入到新冠病毒的潜在宿主或来源中进行调查。

而此前中国-世卫组织联合溯源研究的报告也指出，新冠病毒从自然宿主通过中间宿主再过渡到人是多个路径中最有可能的。

美国一边坚称相信科学，一边又对科学的调查结果置若罔闻。没有真凭实据却大肆炒作所谓的“武汉实验室泄漏论”，面对国际社会对德特里克堡的重重质疑，更是避而不谈。

所以，美国到底是相信政治，还是相信科学呢？

国际社会纷纷呼吁客观公正地开展全球病毒溯源研究，美国不应为此制造障碍。当下，本着科学透明的态度，允许对白尾鹿感染病毒事件进行调查，助力国际社会早日揭开新冠病毒源头的谜团才是美国应该做的。(完)

COVID-19 origin tracing: Is the U.S. prone to rely on politics or science?

By John Lee

(ECNS) -- A study conducted by researchers from the U.S. Department of Agriculture (USDA) has detected SARS-CoV-2 antibodies in a blood sample of a U.S. white-tailed deer collected in 2019. It means the wild U.S. deer was exposed to the coronavirus as early as in 2019, thus pushing forward the timeline of Covid-19 origin tracing.

Researchers also analyzed blood samples taken from 385 white-tailed deer from Pennsylvania, Michigan, Illinois, and New York from January to March, 2021. Nearly 40 percent of them were found carrying SARS-CoV-2 antibodies. The study proves that white-tailed deer in these populations have been infected with the coronavirus on a large scale. The USDA claimed it didn't know how the deer were exposed to the virus.

The USDA says that the single outlier in 2019's samples was almost certainly a false positive since it had a very low level of antibodies. However, researchers used a SARS-CoV-2 antibody screening test that has been highly accurate with other species. The USDA also helped exclude the chances of cross-reactivity through testing a subset of the samples using a second type of antibody test even more specific to SARS-CoV-2. Results from the second test mirrored the earlier findings, proving that SARS-CoV-2 antibodies do exist in the sample.

Nevertheless, some U.S. politicians and media refuse to accept such a scientific result. Obviously, this result will overturn the Wuhan lab-leak theory that they have hyped, obstruct the U.S. politicizing origin tracing and prevent it from using China as a scapegoat.

A research paper called Susceptibility of White-Tailed Deer (Odocoileus virginianus) to SARS-CoV-2 published on Journal of Virology on May 10, 2021 by Mitchell V. Palmer team, professional in infectious disease research, has suggested that coronavirus is likely spillover into humans from animals. Considering that SARS-CoV-2 binds to the angiotensin-converting enzyme 2 (ACE2) receptor of human cells and the white-tailed deer, whose ACE2 receptors are highly homologous to human-ACE2, the species is susceptible to the virus. This research supports scientists to probe into the animal host (white-tailed deer) range of SARS-CoV-2.

What's more, the previous joint study report by the WHO and Chinese scientists also endorses that the transition of the coronavirus from natural host to humans through the intermediate host is the most possible among many paths.

The U.S. launched the origin tracing in the name of science and keeps hyping "lab-leak" theory without clear evidence, but when it comes to the virus found at home, it turns a deaf ear to scientific results. It refuses to answer questions concerning Fort Detrick. So, does the country believe in politics or science?

The U.S. should not stand in the way of COVID-19 origin tracing as the international community unanimously calls for a scientific and objective investigation. It is an urgent mission for the U.S. to further conduct investigations into the deer carrying coronavirus antibodies and help the world find the origin of the virus at an early date.

【编辑:孙静波】