The harmful allele of sickle-cell anaemia has not been eliminated from human population. Such afflicted people derive some other benefit? Discuss.

Sickle-cell anaemia happens due to mutation that’s why still persists in the population despite being harmful and may be beneficial against to malarial infection as the body targets the Plasmodium falciparum infected cell for destruction by mutant genotype haemoglobin HbS/HbA in comparison normal haemoglobin HbA/HbA of RBCs.