Today both France and Spain (two badly hit countries) have come out with seroprevalence numbers. (France is a model, paper linked below. Spain was representative sample/survey of 60K; I don't have the paper yet). Both are ~5 percent. If that holds up, that is very very bad news. https://twitter.com/hsalje/status/1260606369805320195

One hopeful scenario had been there is a lot of asymptomatic transmission we are not noticing. Maybe. But if some of the worst hit countries are still composed of almost completely immunologically naive populations, that's a different challenge. Quite confusing, to be honest.

Clarification re: my Sweden seroprevalence question. Lancet article said 25 percent for Stockholm. The question re:Spain and France only at 5 percent remains, though. If that's the real seroprevalence, big death toll despite (relatively) limited spread. https://twitter.com/oli_bou/status/1260644675083358208