NYC cases of COVID variant known as ‘mu’ show steady decline: health officials

“What drives variants is transmissibility, not how harmful they are,” said Dr. Mitchell Katz, the head of the city’s Health + Hospitals network. “Viruses are not actually trying to harm us. They’re just trying to replicate, and part of why delta is so dominant is not because of its harmfulness, but because of its wild contagiousness.