瑞典的流行病学家安德斯▪蒂格内尔日前指出，瑞典的部分地区最早可能在下个月实现对新型冠状病毒的群体免疫。请看本报昨日的报道：

Parts of Sweden are on track to achieve so-called herd immunity from COVID-19 disease within weeks, according to the man who devised the country’s unusual strategy for dealing with the outbreak.

Anders Tegnell said the Swedish capital, Stockholm, will be among the first places to develop such immunity.

报道中的herd immunity就是“群体免疫”。例如：

Herd immunity is when a large part of the population of an area is immune to a specific disease. If enough people are resistant to a virus, it has nowhere to go. The infection rates drop, and the disease peters out.

群体免疫就是当某一地区的大部分人群对某种疾病产生了免疫力。如果足够多的人对一种病毒有了抵抗力，这种病毒就没有地方传播了。感染率会下降，疾病也就逐渐消失。