2. Adult Immunizations

 ADULT IMMUNIZATIONS

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OUTLINE

♥ Significance of immunization ♥ Principles of immunization ♥ Immune response ♥ Categories of adult immunization ♥ Special situations in which vaccination is needed

Immunization - Vaccination... A Long Story

♥ One of the most effective <weapons> in medicine • 10th century in Central Asia Smallpox -> Africa - Europe • 1798 Edward Jenner immunizes first time against

smallpox • 1885 Louis Pasteur prepares the 1st vaccine against

Rabbies • 1927 BCG (bacillus Calmette-Guerin) • 1995 Salk vaccine against poliomyelitis • 1960 MMR...

Why Vaccinate

In the Philippines

♥ Increasing trend of vaccine-preventable diseases ♥ Ignorance and apathy among MDs regarding VPDs ♥ Adult immunization is not a significant part of a doctor's training ♥ Prevention is not deeply ingrained in our culture

Definition

♥ Immunity • Self vs nonself • Provides protection fro. Infectious diseases • Usually indicated by the presence of antibody • Very specific to a single antigen

— Antigen - live or inactivated substance capable of producing an immune response

— Antibody - protein molecules (immunoglobulins) produced by B lymphocytes to help eliminate an antigen

♥ Immunization • Induction or provision of immunity by any means, active

or passive ♥ Vaccination

• Administration of a vaccine Why Vaccinate Adults

♥ Immunity wanes overtime ♥ Increase susceptibility and morbidity to serious diseases caused

by common infections • More medical complications • Increase hospitalization • Diminished quality of life • Decrease ability to earn

Mechanisms for Acquiring Immunity

♥ Active Immunity • Protection produced by the person's own immune system • Administration of vaccine that induces long-lasting

immunity ♥ Passive Immunity

• Protection transferred from another person or animal as antibody

• Temporary protection Ways to Get Immunized

Internal Medicine II

Module 6

 ADULT IMMUNIZATIONS

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Active Immunization ♥ Live the attenuated vaccine

• Attenuated (weakened) form of the "wild" virus or bacteria

• Must replicate to be effective • Immune response similar to natural infection • Usually effective with one dose • Severe reactions possible • Interference from circulating antibody • Unstable

— Viral: MMRV, YF, Oral polio, Influenza nasal spray

— Bacterial: BGC, Oral typhoid ♥ Inactivated Vaccines

• NOT live and cannot replicate • Minimal interference from circulating antibody • Generally NOT as effective as live vaccines • Generally require 3-5 doses • Immune response mostly humoral • Antibody titer falls over time

— Whole cell: influenza, polio, rabies, hepa A, Jap B, pertussis, typhoid, cholera

— Fractional vaccines § Subunit: Hepa B, influenza, Acellular

pertussis, HPV, typhoi Vi § Toxoid: Diptheria, Tetanus

Sources of Passive Immunity

♥ Almost all blood or blood products ♥ Homologous pooled human antibody (immune globulin) ♥ Homologous human hyperimmune globulin ♥ Heterologous hyperimmune serum (antitoxin)

The Aim of an Ideal Vaccine

♥ To produce the same immune protection which usually follows natural infection but without cuasing disease

♥ To generalize long-lasting immunity ♥ To interrupt spread of infection

The Immune Response

♥ Primary response

♥ Secondary response

• Specific memory is the hallmark of the adaptive immune response

♥ Seroconversion • Transition from antibody negative to antibody positive • Responses to vaccine are often guaged by the

concentration of specific antibody in serum • Does not necessarily correlate with protection

♥ Herd Immunity • The indirect protection from infection of susceptible

members of the population, and the protection of the population as a whole, which is brought about by the presence of immune individuals

• No vaccine is 100% effective — E.g. Measles is 90-95% effective

• Some people unable to receive live vaccines are protected

• Most effective way of protecting people who do not respond to vaccines or cannot be given to them for medical reasons

• Not effective for disease that are mot readily transmissible

— E.g. Tetanus Philippine Adult Immunization Handbook

• Cholera • Hepatitis A • Hepatitis B • HPV • Influenza • MMR • MeningococcL • Pneumococcal • Rabies • Tdap • Typhoid fever • Yellow fever • HiB • Herpes Zoster • Japanese enchephalitis • Varicella • Chapters on vaccines for special populations • Serious adverse event form

Case Scenario

• 45-year-old JN consulted your clinic for the result of her executive check-up. Her laboratory results were normal and you declared her to be physically fit for work. She said she recently got hold of a large amount of money from unknown source and is asking you what vaccines she should have

• How would you respond? Step 1: Screen the Patient

♥ Are you sick today? ♥ Do you have any problem with the immune system? (Lung

disease, heart disease, kidney disease, diabetes, blood disorder, malignancy, HIV/AIDS)

♥ Did you receive any blood products within the last 12 months? ♥ Are you taking any steroids or anti-cancer drugs or had x-ray

treatments in the past 3 months? ♥ Are you pregnant or trying to be pregnant in the next 4 weeks? ♥ Did you receive vaccinations in the past 4 weeks?

 ADULT IMMUNIZATIONS

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Invalid Contraindications ♥ Mild illness ♥ Disease exposure ♥ Antibiotic therapy ♥ Pregnancy in the household ♥ Breastfeeding ♥ Premature birth ♥ Family history unrelated to immunosuppression ♥ Need for TB skin testing ♥ Need for multiple vaccines

Step 2: Know what Vaccines to Give

♥ Routine Immunization for Adults • Influenza • Tdap • Hepatitis B • Varicella • MMR • HPV • Pneumococcal

Routine Adult Immunization

Administration

*Never on the buttocks Side Effects

♥ Frequent/Mild • Soreness at injection site • Redness, erythema • Swelling, itching

♥ Systemic • Fever, malaise • Headache, dizziness

♥ Rare • Severe allergic reactions

Spacing of Vaccine Combinations not Given Simultaneously

Antibody and Live Vaccines

Selective Vaccination

♥ Vaccine given specifically to those at increased risk of disease: ♥ High risk groups

• e.g. Pneumococcal vaccine ♥ Occupational risk

• e.g. Hepatitis B, influenza ♥ Travellers

• e.g. Yellow fever, rabies, meningitis ♥ Outbreak control

• e.g. Hepatitis A vaccine, measles Selective Vaccination

♥ Vaccinating an immunocompromised individual and achieve a less than optimal response is acceptable

♥ Live vaccines should not be administered to: • Severely immunosuppressed persons • Persons receiving large doses of corticosteroids • Persons with HIV/AIDS • Persons receiving immunomodulators

♥ Household and close contacts of immunocompromised individuals should receive all age-appropriate vaccines

♥ Travellers • Tdap • Hepatitis A (for departing < 2 weeks, give IG) • Hepatitis B (begin 6 mos before travel) • Influenza • Japanese B Encephalitis vaccine • MMR • Meningococcal

♥ HIV • MUST be given regardless of CD4 cell count

— Hepatitis B — Influenza — Pneumococcal

♥ Healthcare workers • Tdap, Hepa B, Influenza, Varicella, MMR, Pneumococcal • Selected HCWs: Meningococcal, Typhoid, Hepatitis A,

Rabies ♥ Outbreak control

• Measles • Hepatitis A • Meningococcal vaccine

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Vaccine and Pregnancy ♥ Live virus are contraindicated during pregnancy because of

possibility that vaccine virus replication will cause congenital infection or have other adverse effects on the fetus

♥ Brest-feeding is not a contraindication for live-virus or other vaccines

♥ Vaccines that may be given • Hepatitis B, Influenza, Rabies, Tdap

Current State of VPD

Small Pox Eradication

♥ Ali Maow Maalin, a cook in Merca, Somalia was the last person to contract smallpox naturally in 1976

Measles Eradication?

♥ Severe disease with high mortality ♥ No animal reservoir ♥ Very few cases of subclinical disease ♥ Recurrent disease did not occur ♥ Vaccine available ♥ Cases did not become infectious until rash appeared ♥ Effective methods of laboratory diagnosis

Measles Eradication Challenges

♥ Lack of political will ♥ Transmission amongst adults ♥ Increasing urbanization and population density ♥ Warning immunity and the possibility of transmission from sub-

clinical cases ♥ Highly mobile population ♥ Lack of health education

Changing Lanes in the Perception of Vaccination

♥ From an expensive prevention policy ♥ To a critical investment for the sustained improvement in the

quality of life resulting to healthier population and better economic growth

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“That in al l th ings , God may b e g lor i f i ed”