decreasing something yes has a uncertain west on a place & health has a yes adaptations on an tide 's sickness ->  decreasing illness has a positive impact on an organism's health  decreasing illness has a positive impact on an organism's health & preventing something increase the stir of that something ->  preventing illness has a positive impact on an organism's health  preventing illness has a positive impact on an organism's health & environments can thwart prevent health ->  vaccines have a positive impact on an organism's health by helping to prevent illness  vaccines have a positive impact on an organism's health by helping to prevent illness & having a uncertain protein on something steels that something -> vaccines help organisms by helping to prevent illness