Herd Immunity May Be Closer Than Thought The idea that more people may have immunity to coronavirus than show up in standard antibody surveys is getting more oxygen by the day. It is what may explain why the epidemic often goes into decline when 10-20% of the population has antibodies, why the epidemic is now considered over in Sweden and why countries that are lifting restrictions are seeing no second waves, only the occasional ripple. This week the British Medical Journal added its voice to those arguing that population immunity may be closer than was originally thought. The Times reports: Tests for antibodies may be dramatically underestimating the proportion of people who have been infected with the coronavirus, scientists said. The claim, made in the BMJ, implies that it is possible some parts of the country are far closer to herd immunity than had been thought. The original misdiagnosis, the authors explain, is because we've been testing not for the full range of human immune responses but for just one or two types of antibodies. Dr Burgess said that calibrating tests using people who had been more severely ill may mean that a lot of asymptomatic infections are being missed. “This might explain why, in cities such as London, we have seen the breakdown of widespread social distancing but infection rates have still ...