That depends, are you expecting the first victims to respect social distancing, even before they knew they were infected and that infection would most likely result in death? Are you expecting the first trollifying victims to quietly accept death or eternal restraint, or would they be more likely to try to escape that fate, even at the cost of spreading the disease further? Judging from how well social distancing is currently obeyed ...
But perhaps it would've bought enough time for some not-yet-massively-infected countries to prevent the complete collapse of society.