Transcript Vaccination
Vaccination An Underappreciated Component of the Modern Medical Armamentoarium Vocabulary • Vaccine: – A preparation that contains microorganisms or their parts to which immune systems. • Toxoid: – An inactive toxin that is no longer harmful but retains its unique Ag determinants. Immunizations • Idaho is ranked 50th in immunization for children 19-35 months of age. – 4:3:1 – 4 doses of DTP – 3 doses of oral polio – 1 dose of measles vacine “Involuntary experiment” • 1980-sensationalized and highly inaccurate news accounts of alleged side effects of pertussus caused many parents in the United Kingdom to refuse the pertusus toxoid in DTP. • An epidemic of whooping caugh occurred in the United Kingdom, in which 100,000 children were infected and 36 died. Many of the survivors sustained brain damage. Annual morbidity before the vaccine became available compared to morbidity in 1998 Disease Smallpox Diphtheria Pertussis Tetanus Polio Measles Mumps Rubella Annual morbidity 48,164 175,885 147,271 1,314 16.317 503,282 152,209 823 1998 morbidity 0 1 6,279 34 0 89 606 5 % Decrease 100 100 95.7 97.4 100 100 99.6 99.4 Vaccines-a Health Care Bargain • A good vaccine can provide lifelong immunity to an infectious disease. • Vaccines are much cheaper than diagnosis and treatment of infections after they have started • They prevent human suffering and may be the only form of treatment known for some ailments. Vacinations • Vaccines currently under development – Contraception – Cancer – cocaine addiction • There is no absolute limit to the number of vaccines that can be given to a person. – All standard vaccines recommended for children can be given to the same person, at separate anatomical sites, on the same day Why aren’t there more Vaccines? • Many of the barriers to vaccine development are financial, legal, and political rather than scientific. • Vaccines are not nearly as profitable as mind altering drugs or heart medications. • The development of vaccines have focused on diseases that are widespread and usually not serious. • Numerous lawsuits based on alleged, rare side effects of vaccines. Types of Vaccines • 2 Types of vaccines – Whole-agent • Attenuated (Weakened) • Inactivated (killed) – Subunit (some part of agent) Attenuated • Contain live viruses • Attenuated tend to mimic an actual infection and usually provide better and longer lasting immunity. • Replicates in the body, increasing the original dose over time provides herd immunity • Life long Without boosters • Examples measles, rubella, mumps, oral polio (sabin) all are attenuated and Attenuated Vaccines Cont. • Attenuated viruses are usually derived from mutations accumulated during long term cell cultures. • Danger of such vaccine is that they can back mutate to a virulent form, although this very rarely happens. Innactivated Vaccines Whole Organisms that have been killed – Usually killed by formulin – Never killed by heat. Why? – Boosters: Because immunity is not always long lasting boosters are needed to maintain immunity. – Examples; rabbies, influenza vaccines Subunit vaccines • Vaccines in which antigenic fragments of microrganisms that are best suited to stimulate immune resp. • Recombiant vaccines – example Hepatitis B virus – Portion of the viral protein coat. – (Less effective) - safer Cannot reproduce in host contain little or no extraneous material thus – less side effects DTaP • D (dephtheria toxoid) T (tetnus toxoid) aP (acellular pertussis toxoid and surface adhesin) – subunit vaccine that is very safe – Soluble, elicit a humoral response • Old pertussis vaccine was made from inactivaed whole unit bacteria (Bordetella pertussis)