Immunization PDF

Immunization Immunization Immunization is the means of providing specific protection against most common and damaging pathogens. Specific immunity can result from either passive or active immunization and both modes of immunization can occur by natural or artificial processes ...

Immunization Immunization Immunization is the means of providing specific protection against most common and damaging pathogens. Specific immunity can result from either passive or active immunization and both modes of immunization can occur by natural or artificial processes  Immunization 1 2 3 4 Naturally acquired passive Artificially acquired Naturally acquired Artificially acquired active immunity passive immunity active immunity immunity  I. Passive Immunity 1- Naturally acquired 2- Artificially acquired passive passive immunity immunity Immunity is often artificially transferred Immunity is transferred from by injection with gamma globulin from mother to fetus through other individuals or from an immune placental transfer of IgG or animal (antiserum). colostral transfer of IgA. Passive transfer of immunity is practiced in numerous acute infections (diphtheria, tetanus, measles, rabies, etc.), poisoning (insect-,reptile-bites, botulism), and as a prophylactic measure This form of immunization has the advantage of providing immediate protection, it is effective for a short duration only.  II. Active Immunity This refers to immunity produced by the body following exposure to antigens. 1- Naturally acquired active immunity 2- Artificially acquired active immunity Exposure to different pathogens leads to sub clinical or clinical Immunization may be achieved by infections, which normally result administering live or dead in a protective immune response pathogens or their components against these pathogens. (Vaccination).  Vaccine It is an antigen, when introduced to human body it stimulates the body to form antibody.( It is acquired artificial active immunity). It must be prepared from cultures of non sporing bacteria. It is prepared either as stock or autogenic vaccine. Stock vaccine: Prepared from standard laboratory strains. Autogenic vaccine: prepared from infecting strain ( from patient).  Types of vaccine C- Sub-unit vaccines A- Live attenuated vaccines D- Other novel vaccines B- Killed vaccines A- Live attenuated vaccines The ability of the organism to produce the disease is weakened. Examples live vaccines for measles, mumps, rubella and chicken pox (varicella) are used routinely. Vaccination by these weakened organisms will produced a limited infection and the immune system of normal healthy people quickly kill and eliminate them from the body with production of antibodies which give the immunity to the persons. Advantages 1- The antigen antibody reaction is mild without symptoms. 2- A single dose produces long lasting immunity which reinforced by booster doses. Disadvantages 1- They carry a serious risk of causing disease in immunocompromised individuals. 2- Since live vaccines are often attenuated (made less pathogenic) by passage in animal or thermal mutation, they can revert to their pathogenic form and cause serious illness. It is for this reason, polio live (Sabin) vaccine, which was used for many years, has been replaced in many countries by the inactivated (Salk) vaccine. B- Killed vaccines These consist of whole organisms inactivated by heat, chemicals or UV irradiation treatment. Many killed viral and bacterial vaccines are available. Some of these are used to immunize people at risks (e.g. influenza, hepatitis A, etc.) while others are used to immunize travelers to different countries (e.g. cholera, typhoid etc.). Advantages: They can be used for immunocompromised patient. Disadvantages Several doses are required to produce immunization usually three successive doses, 4-6 weeks in between and booster doses are necessary. C- Sub-unit vaccines They are inactivated bacterial toxins, such as polysaccharide material or proteins components or purified viral antigen such as HB Ag which stimulate the body to produce immune response. Such as tetanus and diphtheria. Disadvantages They are small molecules and require large adjuvant molecule to produce response. D- Other novel vaccines DNA vaccines: Vaccines consisting of DNA fragments that can be transformed into host tissue. In the body, DNA converted into protein which acts as FORIGN material and stimulate the immune system to produce an immune response.  Adjuvants Weaker antigens may be rendered more immunogenic by the addition of other chemicals. Such chemicals are known as adjuvants. There are many biological and chemical substances that have been used in experimental conditions. However, only Aluminum salts (alum) are approved for human use and it is incorporated in DTP vaccine. Furthermore, pertussis itself has adjuvant effects. Adjuvants used experimentally include mixtures of oil and detergents.  Transport and storage of Vaccine preservative vaccines Vaccines must be stored at Preservative are used in temperature 2 to 8 c from the place some vaccines to prevent of manufacture to the point of bacterial or fungal administration. contamination. Vaccines must not be freeze or Thimerosal, a mercury- subject to higher temperature. containing preservative, has ZOSTRAVAX required to be frozen been used from 1930. But (≤ –15 C) now, it is illustrated that MMR can be stored in refrigerator these preservative are very or freezer → Bottom self of toxic and cause mental refrigerator disorder and from 2001 it is Protect from light → MCV, BCG, prohibited to use any Measles vaccine containing mercury. OPV required to be frozen (-20 C) after opening can be kept (2-8) for 6 months  Vaccination and Antibiotics Some vaccines may contain small amount of certain antibiotics (neomycin, streptomycin, gentamycin, polymyxin B) to prevent bacterial contamination during manufacture process. MMR, IPV, ZVL. Patients with allergy to these antibiotics must not be given these vaccines. Combined vaccines Combined vaccines are more attractive than single vaccine because it reduces numbers of injection and response to one vaccine will not affect other vaccines. Vaccination and egg allergy The following vaccines may contain traces of egg proteins: MMR Influenza vaccine Egg allergy with just hives → Take the vaccine Egg allergy with angioedema, respiratory distress, light headache, recurrent emesis; or who require epinephrine or emergency medical intervention → Vaccine is given under supervision of a health care provider who is able to manage sever allergy. Yellow fever vaccine Higher amounts of egg proteins → Allergy specialist is recommended before vaccination When avoid vaccines (Contraindications) 1- Live vaccines in pregnancy. 2- Live vaccines in immunocompromised patients a- Patient receiving cancer chemotherapy ✓ Live vaccines can be given after chemotherapy has been discontinued for at least 3 months. b- Recent hematopoietic cell transplant (HCT) c- Biologic agents (TNF inhibitors, Rituximab, Etanercept) d- All vaccines with CD4 < 200 cells/mm3 e- Receiving daily corticosteroids 3- All vaccines causing sever allergy (Anaphylactic shock) 4- All vaccines in moderate to severe illness with or without fever →→ Given with caution (Not contraindicated) Patients receiving corticosteroids ✓ Live vaccines may be administered to patients receiving the following: Topical steroids Any dose Live vaccines given immediately Systemic steroids less than 2 mg/kg/day "low or moderate Live vaccines given immediately dose“ ≥ 2 mg/kg/day for less …than 14 days Live vaccines given immediately ≥ 2 mg/kg/day for more than 14 days Live vaccines should be delayed at least 1 month after stopping the steroid Influenza (Flu) ❑ Inactivated influenza vaccine (IIV) Can be given with Influenza Antiviral Drug (IAD) like Tamiflu (Oseltamivir) ❑ Live attenuated influenza vaccine (LAIV) IAD cessation → wait 48 hours → Take LAIV LAIV → wait 2 weeks → Take IAD If IAD administered within 2 weeks of LAIV, the vaccine dose should be repeated 48 hours after the last dose of antiviral medication LAIV should not be given to: 1- Patient with severe allergic reaction to LAIV 2- Patient allergic to eggs 3- Pregnant woman 4- Child (2:17) receiving aspirin or aspirin containing 5- Child (2:4) with asthma or wheezing in past year 6- Immunosuppressed patient 7- Patient taken antiviral in the previous 48 hours  Influenza viruses undergo shift and drifts; therefore, every year new influenza (flu) vaccine is formulated and must be administered every year. New influenza season start approximately in November (11) every year The new vaccine must be started in October (10) as it takes about 2 weeks after vaccination for antibodies to develop and provide protection. Child less than 9 years given 2 doses in one flu season, one is a booster dose. → (In 1st time only) Influenza vaccine normally taken once per year but it can be taken twice (every 6 months) in high risk patients. High risk patients include (COPD, hypertension, Dyslipidemia, Female, Old) Not used for children (0:6) months Influenza vaccine is given every year even if you do not need it. Inhaled influenza vaccine → FluMist Hepatitis Hep. A Hep A vaccine is recommended for travel to most parts of the world. Total doses = 2 Hep. B Hepatitis B vaccine is given in a 3-doses series at 0, 1, 6 months. Minimum duration 4 weeks between two vaccines. Pregnant woman with Hepatitis B when she delivers the baby must be given → (HBV) + HBIG Nurse infected with Hepatis B patient blood must be given → (HBV) + HBIG HBV + HBIG → administered at different body sites. Preterm birth → Delay Hep. B vaccine until the baby is: 1- More than 2 kg body weight or 2- More than 30 days old Hep. C There is no vaccine available to provide protection against hepatitis C Others HPV ❖ Human Papilloma virus vaccine 1- ↓ incidence of infertility 2- ↓ incidence of cervical cancer 3- can cause syncope → patients remain seated for at least 15 minutes after receiving the vaccine. RV 1- The 1st dose of RV → before 14 weeks 2- The last dose of RV → before 8 months Hib Haemophilus influenza vaccine should not be given over 5 years child. BCG BCG vaccine against T.B., it has the maximum age → Life-long immunity PCV - PPSV Pneumococcal vaccine given to patients older than 65 years MCV Emergency staff at hospital should receive meningitis vaccine. IPV killed polio vaccine is available (IM injection). OPV sabine vaccine, oral polio vaccine (life attenuated) is widely used. It is affected by heat, it must store in refrigerator (2- 8) MMR It is life attenuated vaccine against measles, mumps and rubella. DPT Less than 7 years✓ DTap immunizatio Above 7 years✓ TD – Tdap n Adult ✓ Adult should receive one Td booster every 10 years. ✓ Adult should replace 1 Td booster with a Tdap dose once in their life time.  Antiserum Blood serum containing antibodies against specific antigens (an infective organism or poisonous substance) ; provides immunity to a disease  1- Antitetanic serum 3- Hepatitis B immune globulin (HBIG) It is used in treatment to It is used in prevention of neutralize the unbound toxins to Hepatitis B in people who prevent the disease from getting may have been exposed to the worse. virus by contaminated needle It is used in prevention to immunize persons with contaminated wounds. 4- Rabies immune globulin (RIG) The antitoxins obtained from It is used in the prevention of humans to avoid hypersensitivity rabies in people who may reactions. have been exposed to the 2- Botulinum antitoxin virus. It is used in the treatment of It is administered by Botulism (strong food injecting as much RIG as poisoning) as the antitoxin possible into the tissue at the neutralize the free toxins so bite site and the remainder is prevent the disease from given intramuscularly. getting worse.  Tetanus immunoglobulin (TIG) Unknown Known history history Minor wounds (10) Td If last Td dose received within 10 years → No treatment If last Td dose received more than 10 years → Td only Major wounds (5) Td + TIG If last Td dose received within 5 years → No treatment If last Td dose received more than 5 years → Td + TIG Hepatitis B immunoglobulin (HBIG) 1- Pregnant woman with Hepatitis B when she delivers the baby must be given → Hepatitis B vaccine (HBV) + HBIG 2- Nurse infected with Hepatis B patient blood must be given → Hepatitis B vaccine (HBV) + HBIG HBV + HBIG → administered at different body sites.