A period of cold is important for the onset of flowering in many plants. This is why an adequate cold period is a prerequisite to having a bountiful harvest, especially fruits.
Also, many of us with AA blood genotype suffer a lot during this period. I am still battling with my own fair share of malaria. Do'nt also forget COVID19, the infection rate is usually high during this period.
Honestly speaking, I am just learning about the association of malaria with this season. Thanks for the enlightenment sir