Question

5. Using vaccination to fight influenza has faced numerous challenges. What are the limitation of the current vaccine and the current vaccination process? How do we improve vaccination coverage for influenza and limit the damage from this infection

Answer 1

Antigenic shift: A major change in one or both of the surface antigens, a change that yields an antigen showing no serologic relationship with the antigen of the strains prevailing at the time is called antigenic shift. Antigenic shift has been demonstrated in type A influenza virus only.

Antigenic drift: Repeated minor antigenic changes, on the other hand, generate strains that retain a degree of serologic relationship with the currently prevailing strain. This is called antigenic drift. The epidemics are caused by influenza A virus undergoing antigenic variations due to antigenic drift resulting from mutations and selections. Antigenic drift variants occur very frequently, virtually every year. This is responsible for emergence of the strains that cause yearly influenza epidemics.

These antigenic shift and drift makes result in variation and evolution of serotype and subtypes of the influenza strain lowering the efficacy of the influenza vaccine.

We can prevent the these problems by expanding the coverage of vaccination and by preventing the emergence of the new strains in a population.

We need to include more strains in the vaccine.