IMMUNIZATION in children updated information
- 2. Outline • Definition • History • Types of immunity • Types of vaccines • Immunization in Uganda 1. Childhood immunisable diseases 2. Routine for immunization 3. Storage of vaccines
- 3. DEFINITION • Immunization : This refers to the process by which a person becomes protected against a disease through vaccination. • Vaccination : refers to the introduction of a killed or inactivated microbe into the body to stimulate an immune response against the disease causing microbe. • Vaccine : this is a preparation that is given to an individual to provide active acquired immunity to a particular infectious or malignant disease.
- 4. Cont……….. The process of giving a vaccine is called immunization however most medical personnel refer to it generally as immunization.
- 6. Types of immunization There are 2 types of immunization • Active immunization • Passive immunization
- 7. Passive immunization • In passive immunization, antibodies are given directly to an individual. These antibodies are obtained from several sources eg 1. Blood from humans 2. Lab grown antibody producing cells 3. From mother to baby through breast milk or via the placenta. • This type of immunization provides a type of immunity known as passive immunity.
- 8. Cont……….. • This does not confer long-term protection but is useful for situations of imminent danger when there is no time to generate antibody by the patient and in cases of immunodeficiency where antibody cannot be made. • The isotype transferred is IgG because it is the most long lasting (with a half-life of 28 days) and it confers the best protection eg anti- rabies igG is used after an animal bite.
- 9. Active immunization • In active immunization, vaccines are used to stimulate the body’s immune system. The body’s immune system responds to the vaccine by producing antibodies that recognize and attack the specific pathogen contained in the vaccine. • The type of immunity acquired is called active immunity. It can be acquired naturally or it can be vaccine induced.
- 10. Cont…………. Naturally acquired active immunity: This is acquired from exposure to the disease organism through infection from the disease organism. Recovery from a disease usually provides a lifelong protection from the disease eg recovery from chicken pox. Vaccine induced immunity: This is acquired through the introduction of a killed or inactivated form of the pathogen through vaccination.
- 11. Types of vaccines (For active immunity) • Immunization may be achieved by administering live or dead pathogens or their components. Vaccines used for active immunization consist of live (attenuated) organisms, killed whole organisms, microbial components or secreted toxins (which have been detoxified).
- 12. Cont……………….. Live attenuated: a virulent organism is weakened so that it produces antigenic response without serious consequences to the host individual eg BCG, Measles, MMR, varicella, yellow fever. Killed or inactivated: pathogens are killed by chemical treatment or heat. They are suitable for both healthy and unhealthy individuals eg pertusis, Hepatitis A, influenza
- 13. Live attenuated vaccines vs Killed vaccines Live vaccines Killed vaccines ADVANTAGES Single dose is enough No danger of spread Produce local immunity Stable and safe Induce cell mediated immunity More convenient for mass immunization DISADVANTAGES Reversion to virulence ie unstable Multiple dosages usually required Difficulty in storage Easily contaminated in storage Not for immunocompromised individuals
- 14. Cont……. Conjugated vaccines: these vaccines do not contain any whole bacteria or viruses at all. They contain components such as polysaccharrides from viruses or bacteria which trigger an immune response eg typhoid Toxoid vaccines: some bacteria produce toxins when they attack the body to trigger an immune response. Some vaccines are made with the inactivated versions of these toxins eg Diphtheria, tetanus
- 15. Cont…….. Recombinant/Sub-unit vaccines : Sub-unit vaccines refer to vaccine agents that are a component of the pathogen rather than the entire pathogen. In general, they are very safe because the immunizing agent is not a whole organism and cannot cause disease. Some viral vaccines (Hepatitis-B and Human papilloma virus vaccines) consist of purified antigenic proteins manufactured after expression from a gene cloned into a suitable vector (e.g., yeast).
- 18. Childhood immunisable diseases • The major diseases immunized in childhood are 1. Polio 2. Measles 3. TB 4. Diphtheria 5. HepB 6. Influenza B 7. Whooping cough/pertussis
- 19. Poliomyelitis
- 20. TB
- 21. Diptheria • Characterized by a white leathery coating on the throat • Fevers, swellings in the neck
- 23. Hepatitis B
- 26. CONT…. • HPV Vaccine is often given to females of reproductive age from 12-26 years.. • Tetanus diphtheria vaccine is given to women aged 15-49 years(5 doses at an interval of +1 month,+6 months,+1 year and +1 year preceding the last dose). Its also often given during pregnancy
- 27. Sites where vaccines are administered
- 35. Vaccine Adverse rxns • Local – Pain and swelling at site of injection – Redness at sign of injection • Systemic – Fever – Malaise – Headache • Allergies – Rare
- 36. Precautions and recommendations • Live vaccines should not be administered to children with immuno-deficiencies • Injections should be given in the lateral thigh • Deep injection and massage reduces the occurrence of cysts • DPT injections might cause fevers within 12-24 hours. So paracetamol can be given • Children above 2 years should not receive pertussis vaccine • In cases of an epidemic measles vaccine can be given at 6 months of age
- 37. Precautions cont….. • Immunization should only be delayed in cases of extreme fever so that any sign of illness is not attributed to the vaccine
- 38. Conditions not contraindicated to immunization • Minor illnesses eg flu or diarrhoea • Allergy, asthma • Prematurity • Malnutrition
- 39. Storage of vaccines • The system of transport of vaccines is at low temperature from manufacturer to the site of vaccination ie cold chain storage. • This is to prevent vaccine failure as vaccines are sensitive to temperature ie potency decreases when they are exposed to inappropriate temperatures. • Heat sensitivity for vaccines is as follows – OPV> IPV, MMR >Cholera, Rotavirus>BCG, HPV> HepB
- 40. Storage cont….. Can be stored in 1. Deep freezer Temp between -15 to -25°C and its used for storing OPV and freezing ice packs 2. Ice lined box/refridgerator/carrier Temp between +2 to +8°C It has 2 parts. The upper part is for storing vaccines like DPT, TT, HepB and the lower part is for storing vaccines such as OPV, BCG, Measles
- 41. Storage cont……….
- 42. References • MSD MANUAL CONSUMER • Nelson,W.E(2019)Nelson Textbook of pediatrics.21st Edition,Elsevier,Amsterdam