BIO220H1 Lecture Notes - Lecture 23: Smallpox, Antigen, Epitope

• School: UTSG
• Department: Biology
• Course: BIO220H1
• Professor: James Thomson

Document Summary

1. 5 million deaths among kids under 5 were due to vaccine preventable illnesses. The a determinant is an antigen and the immune system can respond to this. Part of the imjune response is targeting the a determinant. The a determinant is conservative across all hep b virus strains. A single bp substitution can alter the amino acid in the a determinant, makingthe mutant able to escape the immune system. Theres an increase of mutant frequency in people who have been vaccinated. If these escape mutants get i(cid:374)to a(cid:374) u(cid:374)(cid:448)a(cid:272)(cid:272)i(cid:374)ated i(cid:374)di(cid:448)iduals, the(cid:455) do(cid:374)"t do (cid:449)ell (cid:271)e(cid:272)ause the(cid:455) get out(cid:272)o(cid:373)peted. O(cid:374)l(cid:455) 25% of adults are vaccinated for hepatitis b. We do(cid:374)"t k(cid:374)o(cid:449) ho(cid:449) da(cid:374)gerous the es(cid:272)ape (cid:373)uta(cid:374)t is. The (cid:448)a(cid:272)(cid:272)i(cid:374)e has driven selection and it selectes for the mutant versions. There was the rtss vaccine that came about a few years ago. Rtss is an antigen of the parasite, so we develop immunity to the antigen.