每日英語跟讀 Ep.K142: San Francisco may be first major US city to hit herd immunity, experts say
San Francisco may have become the first major American city to hit herd immunity to the coronavirus, experts say.
San Francisco is still recording a small number of coronavirus cases, about 13.7 per day, said Dr George Rutherford, professor of epidemiology at University of California San Francisco, but they don’t appear to be gaining enough of a foothold in the population to trigger wider outbreaks.
“That is what herd immunity looks like,” Rutherford said. “You’re going to have single cases, but they’re not going to propagate out.” Health officials still lack agreement on exactly what percentage of the population must be immune to COVID-19 to achieve the much-vaunted status of “herd immunity,” when so many people have antibodies against the virus that it can no longer spread widely through the community.
Throughout the pandemic, the vaccination goals to hit herd immunity have been a moving target, a briefing from Yale School of Medicine notes, with experts initially estimating that the virus would have difficulty spreading if 60 to 70 percent of the population was immune. With several variants in circulation, some of which are more contagious, the estimates have been climbing. Many experts now estimate that herd immunity will be achieved when 80 to 90 percent of residents have been vaccinated.
San Francisco has been close to that target. Nearly 80 percent of San Francisco residents eligible to receive the coronavirus vaccine have received at least one shot, according to data from the city’s health department, and 68 percent are fully vaccinated.
舊金山已接近了這個目標。根據該市衛生部門的數據，有資格接種冠狀病毒疫苗的舊金山居民中，近百分之八十至少接種了一劑疫苗，百分之六十八的人已完整接種了疫苗。Source article: https://www.taipeitimes.com/News/lang/archives/2021/06/14/2003759109