Yeah, not all that lethal but did cause hospital overload in places that got caught out by it. Delta is no more lethal but more transmissible. Things could change though I suppose.
Our homegrown Hendra virus was a stud in comparison - 57% lethality but very hard to catch.
There is something about increased immunity due to exposure to some gastro style bugs. I had a couple of Malaysian mates who used to go back to Kuala Lumpar every year. They were born there and were used to drinking the water without ill effect, but when ever they went back they got the chronic shits for the first few days until they got used to the water again. They preferred the shits routine rather than try and not drink the water (crazy mother fuckers)
gastro illnesses are actually big killers in those countries. The idea 3rd worlders have some special defence to disease is heavily outweighed their high density living, low nutrition, high wormloads and lack of medical services. Its why they die more often, from more things than us.
