It's not really true to say "who could have known..." regarding SARS-CoV2. Of course no one could have predicted this exact virus but epidemiologists at the WHO have been pointing out for nearly two decades how vulnerable we are to a pandemic. The USA, naturally, reacted under Trump by dismantling what little capacity it had to deal with such a thing. Luckily for us, covid-19 is harmless, inducing a mortality rate in the hardest-hit countries of less than one-tenth of one percent of the population. It's terrifying to think what would have happened if a more lethal and more easily spread virus had emerged. As for conspiracy theorists, my own experience of these sad people is that it's precisely like talking with religionists: their minds swerve away and are unable to follow a rational train of thought. The best we can hope for is that once we cease our senseless self-crippling lockdowns and massive unemployment (all induced by our panic, thanks to the ever-sensationalist mass media) they fade back into the darkness for a while. As for "everyone can fall prey to conspiracy theories" this is only true if everyone is ignorant. If people would only bother to read the scientific literature and study the data, they'd be a lot less confused, a lot less scared, and a lot less likely to imagine all manner of nonsense including the nonsense we get from politicians and from the mass media.