> Back in February, Lipsitch gave a very rough estimate that, absent intervention, herd immunity might happen after 40 to 70 percent of the population had been infected.

Which is actually a mischaracterization of what the previous article[1] said:

> Lipsitch predicts that within the coming year, some 40 to 70 percent of people around the world will be infected with the virus that causes COVID-19.

At no point does he mention herd immunity. So, no, he's not saying herd immunity at 40%.

[1] https://www.theatlantic.com/health/archive/2020/02/covid-vac...