RIO DE JANEIRO, BRAZIL - A new variety of Covid-19 which seems to have developed in far-western Amazonas state is faster, stronger, and more lethal to young people, according to frontline medical personnel interviewed for this article. Further, it seems to be affecting those previously infected with the original variant. It is running rampant in Manaus, the state capital, where it was thought that up to 40% of the population was already infected, which suggests vaccines . . .