Riley MaendelTC3 BIOL 216 secM01Dr. James R. Jacob4/16/2020Learning Objectives from Chapter 18: Practical Applications of ImmunologyVaccineA vaccine is a suspension of organisms or fractions of organisms that is used to induce immunity. Edward Jenner was the individual who came up with the practice of vaccination.Principles of VaccinationVaccination works because of herd immunity. Controlling a disease does not require everyone to be immune to it, only most of the population. This is called herd immunity, which limits outbreaks to sporadic cases because not enough susceptible people are in the population.Types of VaccinesAttenuated vaccines consist of weakened microorganisms. Lifelong immunity is mostly obtained. The measles, mumps, and rubella vaccines are all attenuated. Inactivated vaccines consist of killed bacteria or viruses. The vaccine for Hepatitis A is an inactivated virus.Toxoids are vaccines directed at the toxins produced by a pathogen. The tetanus and diphtheria toxoids are two examples.Subunit vaccines use antigenic fragments of a microorganism which stimulate the best immune response. The hepatitis B virus consists of a portion of the viral protein coat that is produced by a genetically modified yeast. Conjugated vaccines combine the desired antigen with a protein that boosts the immuneresponse. The vaccine for Haemophilus influenzatype b was developed in this way.