加州一个县的一项研究表明，感染冠状病毒的人的患病率比以前想象的要高得多，这可能会使是否结束大范围封锁的决定变得复杂。
四月初，3300名居住在圣克拉拉的志愿者的血液从一个手指刺伤处提取并进行分析。斯坦福大学的这项研究还没有经过同行评审，并公布在梅德西夫发现2.5%至4.5%的人抗体检测呈阳性。
根据该县200万人口推算，数据预测当时可能有48，000至82，000人感染了该病毒。上限估计比官方统计的1000例高出80多倍。
“我们的发现表明，我们县的感染人数比我们公共卫生部门报告的病例数多50-80倍，”领导这项研究的伊兰·本达维德博士告诉美国广播公司新闻。
结果还表明，冠状病毒死亡率的上限仅为0.2%，远低于全国4.1%的死亡率。
2020年4月17日，西雅图，UW医学免疫学实验室的一项临床试验正在寻找抗非典病毒的抗体。
然而，研究人员表示，还不清楚这样的结果是否适用于该国其他地区，这其中有相当多的告诫。一些科学家也对研究中使用的试剂盒的准确性和可靠性表示担忧，自然报道。
Bendavid指出，大约95%的圣克拉拉人口仍然没有抗体，很难决定是否放松限制，因为“知道90%以上的人口没有抗体将使这成为一个非常困难的选择。”
公共卫生官员表示，广泛的抗体测试有助于帮助政府决定是否让人口重返工作岗位，因为这些测试有助于找出风险较低的人群。
这项研究可以指出群体免疫尽管专家坚持认为健康政策的选择应该遵循进一步的测试。
加州大学伯克利分校的流行病学教授阿瑟·赖因戈尔德(Arthur Reingold)没有参与这项研究，他说:“这将成为安全重返工作岗位并让我们正常运转的通行证，但这种想法有两个限制:我们不知道抗体是否能保护你，保护时间有多长，而且很小一部分人甚至有抗体。”《卫报》。
ANTIBODY STUDY SHOWS COVID-19 RATE OF INFECTION MAY BE UP TO 85 TIMES HIGHER THAN REPORTED
Astudy in a county in California suggests that the prevalence of people infected with the coronavirus is much higher than previously thought, potentially complicating decisions on whether to end widespread lockdowns.
Blood from 3,300 volunteers living in Santa Clara was extracted from a finger prick and analyzed at the start of April. The Stanford University study, which has not been peer reviewed yet and was posted on medRxiv, found that between 2.5 percent of 4.5 percent of people tested positive for antibodies.
Extrapolated over the county's population of two million, the data predicts that between 48,000 and 82,000 people could have been infected with the virus at that time. The upper estimate is more than 80 times higher than the official case count of 1,000.
"Our findings suggest that there is somewhere between 50- and 80-fold more infections in our county than what's known by the number of cases than are reported by our department of public health," Dr. Eran Bendavid, who led the study, told ABC News.
The results also suggested that the upper limit of the coronavirus's mortality rate was only 0.2 percent, much lower than the nationwide death rate of 4.1 percent.
A clinical test in the Immunology lab at UW Medicine looks for antibodies against SARS-CoV-2 on April 17, 2020 in Seattle.
However there are considerable caveats with researchers saying that it is not clear whether such results would apply to the rest of the country. Some scientists have also expressed misgivings about the accuracy and reliability of kits used in the studies, Nature reported.
Bendavid pointed out that around 95 percent of the Santa Clara population were still without antibodies and it would be tough to decide whether to ease restrictions because "knowing that well upwards of 90 percent of the population doesn't have antibodies is going to make that a very difficult choice."
Public health officials say widespread antibody tests are instrumental in helping governments decide whether to return populations to work because those tests can help figure out who is less at risk.
The study could point toward the development of herd immunity, although experts insist health policy choices should follow further tests.
"The idea this would be a passport to going safely back to work and getting us up and running has two constraints: we do not know if antibodies protect you and for how long, and a very small percentage of the population even has antibodies," said Arthur Reingold, an epidemiology professor at UC Berkeley, not involved in the study, according to The Guardian.
The graphic below, provided by Statista, shows the growth of COVID-19 cases in three U.S. states.
The graphic below, provided by Statista, shows the number of confirmed COVID-19 cases, the disease caused by the new strain of coronavirus, in a selection of states.
