Science reports:

Surveying large swaths of the public for antibodies to the new coronavirus promises to show how widespread undiagnosed infections are, how deadly the virus really is, and whether enough of the population has become immune for social distancing measures to be eased. But the first batch of results has generated more controversy than clarity.

The survey results, from Germany, the Netherlands, and several locations in the United States, find that anywhere from 2% to 30% of certain populations have already been infected with the virus. The numbers imply that confirmed COVID-19 cases are an even smaller fraction of the true number of people infected than many had estimated and that the vast majority of infections are mild. But many scientists question the accuracy of the antibody tests and complain that several of the research groups announced their findings in the press rather than in preprints or published papers, where their data could be scrutinized. Critics are also wary because some of the researchers are on record advocating for an early end to lockdowns and other control measures, and claim the new prevalence figures support that call.

Some observers warn the coronavirus’ march through the population has only just begun, and that even if the antibody results can be believed, they don’t justify easing controls. “You would have hoped for 45% or even 60% positive,” says Mark Perkins, a diagnostics expert at the World Health Organization. “That would mean that there is lots of silent transmission, and a lot of immunity in the population. It now looks like, sadly, that’s not true. Even the high numbers are relatively small.” [Continue reading…]