The explanation I saw, and which sounded reasonable to me was that ivermectin did help reduce covid mortality -- in countries where water-bourne parasites are c

The explanation I saw, and which sounded reasonable to me was that ivermectin did help reduce covid mortality -- in countries where water-bourne parasites are common. People could have a parasitic infection without realizing it and this would act to stress the immune system making it harder to fight the covid virus. When the took ivermectin, it cleared that parasitic infection giving them a better chance again covid. In areas that don't have many parasitic infections, like in northern countries, ivermectin had no effect on covid.