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Transcript of Vaccine Overview Support for this program is made possible by the AAFP Foundation through a grant...
Vaccine Overview
Support for this program is made possible by the AAFP Foundation through a grant from Pfizer Inc.
Vaccine Overview
Developed for AFMRD by
Gail Colby, M.D. and Wendy Biggs, M.D.
Midland Family Medicine Residency
2010
Ehab Molokhia, MD and Gerald Liu, MD
University of South Alabama Family Medicine Residency
Updated 2012
Vaccine Overview
Objectives• Medical knowledge
– Describe the differences in active, passive and herd immunity
– Explain the difference between a live-attenuated and an inactivated vaccine
– State 3 true contraindications to vaccines
• Interpersonal communication– Explain to parents or guardian the reasons
for immunization
Vaccine Overview
Objectives• Systems-based practice
– Utilize resources to find vaccine recommendations and schedules
– Access the Immunization Information System for your state
– Explain the content of Vaccine Information Sheets
– Discuss the purpose and limitations of the Vaccine Adverse Event Reporting System
Vaccine Overview
Mr. and Mrs. A have recently moved to your town, and are now new patients. They bring their 4-month-old girl, 3-year-old and 5-year-old boys to you for well-child exams. The oldest children have no health issues. The baby, born by C-section, initially had some respiratory problems, but has been healthy since hospital discharge at day 4 of life.
Case
Vaccine Overview
When you inquire about immunizations, Mrs. A states “Well, the two oldest children were immunized. I’m too worried about the baby, so she has not had any shots. No one gets those diseases anymore, so I didn’t think she needed them any way.”
Case
What do you tell Mrs. A about why we vaccinate?
Vaccine Overview
Why Do We Vaccinate?• Prevent disease from occurring• Reduce morbidity and mortality if
disease acquired
Vaccine Overview
Do Vaccines Work?• Disease incidence declined rapidly after
vaccine available for that disease• Current U.S. sources of vaccine
preventable illnesses are:– Foreign born people living in the U.S.– Unvaccinated U.S. citizens
Vaccine Overview
Do Vaccines Work?Measles Example
Photo from www.cdc.gov. Image in public domain.
Vaccine Overview
Do Vaccines Work?• During the 1970’s, the hospital in your
town had one floor (50 beds) dedicated to pediatric patients. In 1996, the unit was down-sized to 30 beds. In 2004, volume was so low, the inpatient pediatric unit was closed.
What happened?
Vaccine Overview
What Happened?• The Hemophilus influenza
type b vaccine
Vaccine Overview
Hemophilus influenza type b • Hemophilus influenza type b (Hib)
causes serious infections• Prior to vaccine
– 1:200 children <5 years developed invasive Hib disease
– Estimated 20,000 cases invasive Hib/year prior to vaccine
Vaccine Overview
Hemophilus influenza type b• Vaccine introduced 1988
• 85-92% reduction in Hib invasive disease
– Dramatic reduction
• 1987 – Incidence 41/100,000
• 2000 – Incidence 1.6/100,000
• 2004 – Incidence 0.14/100,000
Vaccine Overview
Hemophilus influenza type b
– HIB meningitis now rare
– Inpatient pediatric units’ decline in
admissions parallel decline in
invasive Hib
Vaccine Overview
What if We Don’t Vaccinate?• Pertussis (Whooping cough)
– 1974: Great Britain decreased vaccination– 1978: epidemic of >100,000 cases of pertussis
and 36 deaths
• Diphtheria– Newly Independent States (NIS) (former
Soviet Union)– 1989: 839 cases of diphtheria– 1994: >157,000 cases and 5000 deaths
Vaccine Overview
What if We Don’t Vaccinate?• The diseases are still around
– 2002: Measles epidemic in Italy– 2003: Adult dies in U.S. of diphtheria – 2008: Child dies of diphtheria in Great
Britain– June 2009 - January 2010: Over 1,500
cases of mumps in the U.S.
Vaccine Overview
What if We Don’t Vaccinate?• Herd immunity
keeps the diseases
in check
– What is herd immunity?
Vaccine Overview
Herd Immunity• Most of population immunized
• Disease itself still exists, but spread
prevented by lack of available hosts
• Unimmunized person less likely to
come in contact with infected person
Vaccine Overview
Mr. and Mrs. A thank you for taking the time to explain why vaccines are given. You tell them that the 4-month-old is now “behind” in immunizations. Today she will receive vaccines for tetanus, diphtheria, pertussis, Hib, Hepatitis B, polio, and pneumococcus. Mr. A exclaims “Are so many vaccines at one time safe?”
Case
Vaccine Overview
Common Misconceptions• Many people believe giving multiple
vaccines must increase the risk of harmful side effects– URI exposes child to 4-10 antigens– Strep pharyngitis exposes to 25-50 antigens– Body generates a greater immune response
to multiple antigens– Studies show vaccine combinations are safe
and effective
Vaccine Overview
Mrs. A states, “I know someone whose child got the pertussis vaccine, but then she still was diagnosed with whooping cough and hospitalized. How is that possible?”
Case
Vaccine Overview
Common Misconceptions• Some believe vaccines don’t work since
vaccinated children still get disease– No vaccine is 100% effective (most 85-95%)– Example: A measles outbreak occurs in a
high school• Vaccination rate 98%• 27 measles cases occur
– 70% in vaccinated teens (n=19) » “Vaccine failures”
Vaccine Overview
Mrs. A exclaims, “But I thought Emily couldn’t get vaccines today. She’s had a runny nose all week.”
Case
Can You Give Vaccines with a URI Present?–Yes
Vaccine Overview
Other Common Misconceptions• Child needs to have
physical exam first• Can’t be on antibiotics• Had fussiness after last
vaccine• Brother had an adverse
reaction
Vaccine Overview
True Contraindications • Which of the following are true
contraindications to giving vaccines?1. Encephalopathy within 7 days of DTaP2. Prematurity3. Family history of seizures4. Progressive neurological disorder (infantile
spasms)5. Anaphylaxis after DTaP6. Is less than 6 weeks old and needs Hib
Vaccine Overview
True Contraindications1. YES - Encephalopathy within 7 days of DTaP
2. NO - Prematurity
3. NO - Family history of seizures
4. YES - Progressive neurological disorder (infantile spasms)
5. YES - Anaphylaxis after DTaP
6. YES - Is less than 6 weeks old and needs Hib
Vaccine Overview
Mr. A wonders, “I heard that live vaccines are more dangerous. Which of those vaccines she’s getting today is a live one?”
Case
Which Vaccine is Live?–None
Vaccine Overview
Types of Immunity
• Herd Immunity
• Active Immunity
• Passive Immunity
Vaccine Overview
Active Immunity• Vaccinations provide active immunity
• Acquired by surviving infection or receiving vaccination
• Protection produced by the person’s own immune system
• Usually permanent
Vaccine Overview
Immunity• T-cell dependent immunity
– T helper cells carry antigen to activate B
cells to produce antibodies
– Strong memory response generated
– Seen with all vaccines except
polysaccharide vaccines
Vaccine Overview
Immunity• T-cell independent immunity
– Antigen directly stimulates mature B-lymphocytes
– Produces mostly IGM– No memory cells due to lack of plasma cell
stimulation– Poor response by children < 2 years old– Seen primarily with polysaccharide
vaccines
Vaccine Overview
Types of Vaccines• Live-attenuated• Inactivated
– Whole– Fractional– Polysaccharide– Conjugated
Vaccine Overview
Live-attenuated Vaccine (LAV)• Modified “wild-type”
– Retains its ability to replicate– Usually non-infectious– Immune response identical to natural
infection
• Most LAV for viruses• 2 LAV for bacteria
Vaccine Overview
Live-attenuated Vaccine (LAV)• Measles• Mumps• Rubella• Varicella• Zoster (same virus
as varicella vaccine but in higher concentration)
• Rotavirus• Intranasal influenza• Yellow fever• Vaccinia (smallpox)• Oral polio vaccine
(no longer available in the United States)
Currently available live-attenuated viral vaccines
Vaccine Overview
Live-attenuated Vaccine (LAV)• Current LAV against bacteria
– Typhoid
– BCG (not available in U.S.)
Vaccine Overview
True Contraindications for Live Vaccines• NO live vaccines if
– Pregnancy
• During pregnancy
• Up to 4 weeks prior to conception
– Immunosuppression
• HIV with severe suppression (CD4 count < 200)
• On prednisone 20mg daily or 2mg/kg for > 2 weeks
Vaccine Overview
True Concerns for LAV’s• Severe reactions possible
– Usually in persons with immunodeficiency
• Antibody interference– Other live vaccines
• LAV’s must be given together or separated by 28 days
– Exogenous or trans-placental antibodies• Immune globulins like IVIG
• Fragile– Heat and light can damage LAV– Requires careful storage and handling
Vaccine Overview
Inactivated Vaccines• Produced by inactivating virus or
bacteria with heat or chemicals• Cannot replicate or cause disease• Less interference from circulating
antibodies• Generally requires 3-5 doses• Antibody titer decreases with time
Vaccine Overview
Inactivated Vaccine Types• Inactivated whole virus
• Fractional
• Toxin
• Polysaccharide
• Conjugated
Vaccine Overview
Inactivated Vaccines• Inactivated whole virus vaccines
– Polio– Hepatitis A– Rabies
• Toxin vaccines– Diptheria– Tetanus
Vaccine Overview
Inactivated Vaccines• Fractional vaccines
– Composed of virus sub-units
• Influenza
• Hepatitis B
• Acellular pertussis
• Human papilloma virus
• Anthrax
Vaccine Overview
Inactivated Vaccines • Polysaccharide vaccines
– Unique sub-unit vaccine
– Long chain sugar molecules that compose the capsule of an organism
– Minimal booster effect
– Poor response in children < 2 years old• Related to immature immune system
Vaccine Overview
Inactivated Vaccines• Available polysaccharide vaccines
– Pneumococcal 23-valent vaccine
– Meningococcal polysaccharide vaccine (Menomune®)
– Salmonella Typhi vaccine
– The 1st Hemophilus influenza type b vaccine• No longer available in U.S.
Vaccine Overview
Inactivated Vaccines • Conjugated vaccines
– Developed in the late 1980’s– Polysaccharide vaccine conjugated to a
protein– Changes to T-cell dependent immunity • Triggers a strong memory response
– Increased immunogenicity in infants/children
– Allows for booster effect
Vaccine Overview
Inactivated Vaccines• Available conjugated vaccines
– Hib was first – Pneumococcal conjugate• PCV 7 and PCV 13
– Meningococcal conjugate• Menactra™ and Menveo®
Vaccine Overview
Passive Immunity• Transfer of antibody to humans
• Provides temporary disease protection
• Trans-placental transfer to infant is
most common
Vaccine Overview
Passive Immunity• Immune Globulins (Homologous Pooled
Human Antibody) – Made from combined IGG fraction of donated
plasma from thousands of adults– Polyclonal, contains antibodies to multiple diseases– Interferes with live vaccines – Examples
• Post-exposure prophylaxis Hepatitis A (Hep A immune globulin)
• Post-exposure prophylaxis to Measles
Vaccine Overview
Passive Immunity• Homologous Human Hyperimmune
Globulin– Made from human serum with high titers of
desired antibody – Other antibodies may be present due to
human serum– Examples
• Hepatitis B Immune Globulin• Rabies Immune Globulin• Varicella Immune Globulin• Tetanus Immune Globulin
Vaccine Overview
Passive Immunity• Anti-toxins (Heterologous Hyperimmune
Serum)– Animal antibodies made to a disease– Usually made from horses– Risk of serum sickness • Immune reaction to horse protein
– Examples• Botulism anti-toxin• Diphtheria anti-toxin
Vaccine Overview
Passive Immunity• Monoclonal Antibodies
– Developed in laboratory– Clone of single B-cell line specific to disease– Will not interfere with live vaccines– Being used to treat other diseases• Rheumatoid arthritis, non-Hodgkin’s lymphoma,
Crohn’s disease
– Example• RSV (Synagis®)
Vaccine Overview
When Do You Give Vaccines?• Need to know
– Recommended age for dose
– Minimum age for that dose
– Recommended interval to next dose
– Minimum interval to next dose
Vaccine Overview
How Do You Know What to Do?• Epidemiology and Prevention of Vaccine-
Preventable Diseases. The Pink Book: Course Textbook 12th Edition
• On-line resources– www.cdc.gov/vaccines
• (National Immunization Program)
– www.immunize.org/childrules • (Immunization Action Coalition)
– www.cdc.gov/vaccines/programs/iis/contact-state.htm • State Health Department immunization programs
Vaccine Overview
Resources• Centers for Disease Control and
Prevention (CDC) publishes grids for children, adults and catch-up schedules– Laminated cards– Available for hand-held devices– Keep on hand (difficult to memorize)– Need to know general concepts
Vaccine Overview
Recommended Immunization Schedule for Persons Aged 0 through 6 Years
Vaccine Overview
Recommended Immunization Schedule for Persons Aged 7 Through 18 Years
Vaccine Overview
Vaccine Overview
Summary of Adult Vaccinations
Vaccine Overview
What Do You Do if the Child Falls Behind in Immunizations?• DO NOT RESTART THE SERIES
– Follow the minimum interval guidelines
– Some doses may not need to be given
Vaccine Overview
What Do You Do if the Vaccines are Unavailable?• Vaccine shortages occur
– Companies leaving the vaccine market
– Manufacturing or production problems
– Insufficient stockpiles
• Can affect vaccine administration
schedule
Vaccine Overview
What Do You Do if the Vaccines are Unavailable?• Temporary changes may be made in
recommendations for use
– Need to keep records of children who
missed a dose
– Use catch-up table for updates
Vaccine Overview
Vaccine Overview
Immunization Information Systems (IIS)• Mandatory vaccine reporting
• All states and US territories (except New
Hampshire and the Marshall Islands) have
a system
– www.cdc.gov/vaccines/programs/iis/contact-
state.htm
Vaccine Overview
Immunization Information Systems (IIS)• What are some of the benefits of IIS?
– Consolidate immunizations given into one source
– Simplifies record keeping– Easily find records for new patient in practice– Provides official copies of immunization records – Facilitates vaccine reviews of a practice– Is up-to-date with recommendations, so new
vaccines can be flagged to be given to patients– Is free to providers
Vaccine Overview
Immunization Information Systems (IIS)• What could be some parent concerns?
– Confidentiality• IIS must protect privacy of all users• IIS can provide a copy of their confidentiality
statement• Since it is a public health activity, reporting to
IIS is exempt from HIPAA (Health Insurance Portability and Accountability Act of 1996) Privacy Rule
Vaccine Overview
Example:Michigan Care Improvement Registry (MCIR) –Michigan’s Immunization Information System
Vaccine Overview
Vaccine Information Sheets (VIS)• One-page (2-sided) information sheets
describing risks and benefits of vaccines
• Produced by CDC• Federal law mandates VIS must be
given for each vaccine listed in the National Childhood Vaccine Injury Act of 1986
Vaccine Overview
Vaccine Information Sheets (VIS)• As of June 2009, must
give VIS for– DTaP – MMR – Polio – Hepatitis A – Hepatitis B – Hib – Varicella – Influenza – Pneumococcal Conjugate
Vaccine Overview
Vaccine Information Sheets (VIS)• Given to each recipient or his/her
parent/guardian prior to administration of each dose of vaccine.– May be available electronically or on paper– May be read before the visit– Edition date of the VIS must be recorded in
permanent medical record
Vaccine Overview
Vaccine Information Sheets (VIS)• Are updated as needed
• Available at http://www.cdc.gov/vaccines
or from state health department
• Available in 37 languages
Vaccine Overview
Sample VIS
Vaccine Overview
Vaccine Adverse Event Reporting System (VAERS)• National vaccine safety surveillance system co-
sponsored by CDC and FDA• Collects information about adverse events and
possible side effects• VAERS Table of Reportable Events Following
Vaccination indicates what providers must report (http://vaers.hhs.gov/resources/VAERS_RET.pdf)– Examples: anaphylaxis, encephalopathy,
thrombocytopenic purpura
Vaccine Overview
Vaccine Adverse Event Reporting System (VAERS)• Individuals can report adverse reactions
on-line, fax or mail form http://vaers.hhs.gov/esub/index
• Limitations– Under-reporting? – Selective reporting?– Does not establish causality– Can not calculate rates of adverse reactions
from data
Vaccine Overview
Summary• Medical knowledge
– Types of Immunity• Herd – most of population immune to the disease• Active – acquired by the disease or immunization• Passive – antibodies given
– Live-attenuated vaccine – non-infectious virus/bacteria stimulates immune response
– Inactivated vaccine types – Whole, fractional, polysaccharide, conjugated
Vaccine Overview
Summary• Medical knowledge
– True contraindications to vaccines• NO live vaccines to pregnant or immune-
compromised patients• Anaphylaxis• Progressive Neurological Disorder (infantile
spasms)• Encephalopathy within 7 days of DTaP• Hib should only be given to an infant 6 or more
weeks of age
Vaccine Overview
Summary• Interpersonal communication
– Explaining reasons for immunization to
parents or guardian takes time.
• Evidence supports vaccines decrease disease
and are safe and effective
• CDC provides tools to assist giving information
to patients
Vaccine Overview
Summary• Systems-based practice
– Each state has an Immunization Information System accessible on the internet at www.cdc.gov/vaccines/programs/iis/contact-state.htm
– Through IIS, providers know what vaccines a person has received and which vaccines they need.
Vaccine Overview
Summary• Systems-based practice
– Vaccine Information Sheets (VIS) list the risk and benefits of each vaccine and must be given prior to the administration of most vaccines
– Individuals and health care providers can report possible vaccine side effects to the Vaccine Adverse Event Reporting System (VAERS)