1. Lecture 15 Vaccines

2. History 1717- Turkey- smallpox from sick person into veins of well person Variolation- mortality rate- 1% Edward Jenner received this treatment at age of 8

3. Edward Jenner Observed milkmaids who became infected with cowpox, did not get smallpox Experiments- inoculated people with cowpox in order to prevent smallpox infection Vaccination: Vacca=cow Vaccine= Smallpox eliminated worldwide

4. Vaccines Prevention can control many communicable diseases Bacterial diseases can often be treated with antibiotics, if prevention fails Viral diseases, not easily treated Vaccination only feasible means of controlling viral diseases Herd immunity=

5. Types of Vaccines 1.Live attenuated vaccines 2.Inactivated vaccines 3.Toxoid vaccines 4.Subunit vaccines 5.Conjugate vaccines 6.DNA vaccines 7.Recombinant vector vaccines

6. Attenuated whole-agent vaccine Use living, but weakened microbes More closely mimic an actual infection generally life-long immunity 95% effective for many vaccines

7. Inactivated whole-agent vaccine Use microbes that have been killed Still provokes immune response

8. Toxoid vaccine Inactivated toxins Remember- toxins are produced by some bacteria and these are what cause the disease

9. Subunit vaccine Use only the part of the antigen that stimulates a strong immune response Safer- can not reproduce in the recipient Also, little or no extraneous material, and therefore less side effects

10. Conjugate vaccine Some types of vaccines use polysaccharides Child’s immune system do not respond well to polysaccharides until 15-24 months Polysaccharides combined with another protein to make vaccine

11. Nucleic acid vaccines Depend on ability of some cells to: –take up and translate foreign DNA –display the resulting proteins, inducing a strong immune response One has been approved for humans

12. Development of new vaccines Vaccines most desirable method of disease control Early successful vaccines cultured in animals With cell culture- could make vaccines that would not grow on anything but human cells Some vaccines do not need cell culture- recombinant vaccines and DNA vaccines Plant potential source for vaccines In future- possibility for vaccines to treat addiction, Alzheimer's, disease and cancer

13. Safety of vaccines Sometimes possibly to cause the disease while trying to prevent it Risk considered worthwhile Public reactions to such risks has changed Some believe connection between autism and MMR vaccine No studies have shown evidence of this