Why do mutations makes it difficult to create a vaccine ? (4 marks - has the potential to be worth more in an exam)

If the mutation rate is high then this can change the DNA composition of the cells. If the DNA changes then so do all the protiens in the cell. This is becauase DNA codes for all the protiens in the cell. This leads to a differences between the antigen (protien present on the surface of a pathogenic cell). A vaccine has a very specific antigen and if its composition changes it will be able to evade the immune system.Thus leading to a lack of complementory antibodies. Key words and points that examiners look for (extra information is included above to make explanations easier) 1.DNA ( needs to be linked to how it influences change in the antigen) 2.Antigen 3.Immune system 4.Antibodies