Immunization concerns revised 3-2-2011 - final [compatibility mode]


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Immunization concerns revised 3-2-2011 - final [compatibility mode]

  1. 1. Immunization Concerns: Separating Fact from Fiction Nancy R. Kelly MD, MPH UT Southwestern Medical Center OutlinePublic health impact of vaccinesVaccine schedulesSchool requirementsVaccine refusal fGeneral vaccine concernsCommon vaccine-specific concerns vaccine-Reputable and not-so-reputable resources not-so- Public Health ImpactVaccines are one of the greatest success storiesin modern medicine. 1
  2. 2. Recommendations Advisory Committee forImmunization Practices (ACIP) Recommendations Advisory Committee forImmunization Practices (ACIP) 2
  3. 3. Why Do Parents Refuse Vaccines? Misperceptions – Child not susceptible to disease – Disease not serious – Vaccines don’t work – Vaccines not safe Parents don’t want to do anything that might harm their childWhen Parents Refuse Vaccines Listen to their specific concerns Address parental concerns Provide information from reputable sources Know websites and resources parents are using Help parents feel their decision to vaccinate is the right one 3
  4. 4. Problems with Vaccine Refusal Puts individual child at risk of disease Puts community at risk of disease outbreaks – 95% vaccination rate needed for “herd immunity” – Some individuals can’t get vaccinated or don’t respond to vaccine General Vaccine Concerns Concern“I don’t think vaccines are safe. How are they tested and monitored?” 4
  5. 5. Vaccine Safety - LicensureVaccines must be FDA approved for usein the US– Process takes up to 10 years!– Animal studies– Human clinical trials– Review by FDA (studies, vaccine plant inspection)– Licensure by FDA– Monitoring of samples from each vaccine lotVaccine Safety - MonitoringThe Vaccine Adverse Event ReportingSystem (VAERS)– National program of CDC and the FDA– Monitors safety of vaccines after licensure– Anyone can report a problem after a vaccine– Method of detecting possible adverse effects– Doesn’t prove vaccine caused problemVaccine Safety - MonitoringVaccine Safety Datalink– Created by CDC– Partnerships with 8 large HMOs– Patients’ medical records used to analyze vaccine related information– 5.5 million people in WA, OR, CA, CO, MN, MA– Compare outcomes in vaccinated vs. unvaccinated children 5
  6. 6. Concern “Vaccines Don’t Work”If vaccines works so well, then why do vaccine- vaccine-preventable diseases occur more often in vaccinated people than unvaccinated? 100 college students living in dorm 95 vaccinated 5 not vaccinated MEASLES OUTBREAK 6/95 (6%) 4/5 (80%) get measles get measlesUnvaccinated people were 35 x more likely to get measles than vaccinated (JAMA, July 1999) JAMA, 6
  7. 7. Concern “ Vaccines aren’t Necessary”Since almost everyone else is immunized, and there is not much disease going around, around why does my child have to be immunized? Concern “Vaccines aren’t Necessary” Three good reasons: – prevalent diseases (ex: pertussis) a child is at pertussis) high risk if not vaccinated – less common diseases still present in diseases, environment (ex: measles) outbreaks occur measles) when immunization rates decrease. – diseases eliminated from our country (polio), (polio), outbreaks still occur in other countries and can cause disease in the US given increased international travel. Concern “Babies are Too Young to Get Vaccinated”I would rather wait until my baby gets older and stronger to give him his immunizations. immunizations 7
  8. 8. Concern “Babies are Too Young to Get Vaccinated” Infants are vaccinated to protect them from disease when they are most susceptible tibl – Pertussis – infects 8000/yr and kills 5-10 in 5- the US, most under 1 year of age – Children < 2 at greatest risk for Haemophilus influenza B (Hib) infection Concern“Is it Better to be Naturally Infected than Immunized?” Wouldn’t it be better for my child just to get natural disease rather than the vaccination and then have better immunity against that disease? Concern“Is it Better to be Naturally Infected than Immunized?” Natural infection causes better immunity than vaccination (exceptions: Hib, pneumococcal and tetanus) Vaccines require several doses Trade off for better immunity is risk of morbidity from natural infection – paralysis from polio – mental retardation from Hib – liver failure from hepatitis B – deafness from mumps – pneumonia from Varicella 8
  9. 9. Concern Illness and Vaccination My child has a cold and I don’t think she should get her vaccinations today. Concern Illness and Vaccination Mild illness NOT a contraindication to getting vaccines – Represents a missed vaccine opportunity – No increased risk of adverse effects – No evidence of decreased immune response Moderate or severe illness, with or without fever is reason to delay vaccines – Evolving signs of illness may be confused with an adverse reaction to vaccine Concern “Should I Use an ‘Alternate’ or‘Selective’ Immunization Schedule?” Alternate schedules - Delay vaccines Selective schedules – Defer some vaccines No evidence that vaccines given at age <2 years are harmful to recipient Some of most serious childhood illnesses attack children < 2 years No evidence that giving multiple vaccines at one time is harmful 9
  10. 10. Vaccine-Vaccine-Specific ConcernsWhat vaccine should be given to thisnewborn baby prior to discharge from thehospital? 10
  11. 11. Concern “If I don’t have Hepatitis B, why should I immunize my baby at birth? She will not be sexually active for y years.” Hepatitis B Hepatitis B – Virus transmitted via blood or body fluids – causes liver disease Person-to- Person-to-person spread can occur with close non-sexual contact non- – Virus can survive in environment >1 week – Transmission can occur by sharing washcloths, razors, toothbrushes – Some people with hepatitis B don’t have symptoms but still can spread diseaseA healthy 2 month old girl is seen at the localhealth department for her vaccinations. Shereceived hepatitis B vaccine at birth.What immunizations does she need today? 11
  12. 12. Concern “I don’t want my baby to getrotavirus vaccine. I heard it causes bloody diarrhea”Rotavirus – Causes vomiting and diarrhea – Risk of dehydration in youngIntussusception – a condition in which oneportion of the intestine telescopes into a nearbyportion causing intestinal obstruction ConcernRotavirus Vaccine & Intussusception Rotashield® rotavirus vaccine tested in 10,054 children before licensed in 1998 Vaccine given to 1 million children (1998-1999) (1998- 15 cases of intussusception in infants after receipt of vaccine reported to VAERS Vaccine attributable risk ~ 1/11,000 Rotashield® taken off the market in 1999 Example of how VAERS surveillance works 12
  13. 13. New Rotavirus VaccineRotaTeq®– licensed in 2006– Pre-licensure clinical trial >70,000 infants Pre-– Post-licensure studies - NO increased risk of Post- intussusception– Decreased need for hospitalization or ED visit by 85% Another New Rotavirus VaccineRotarix®– licensed in 2008– Requires only 2 doses– Recent data from studies in Mexico suggest slight increased risk of intussusception after 1st dose (1/100,000)– Risk of serious rotavirus disease > risk of intussusception– Vaccine label changed to reflect slight increased risk Concern “I don’t want to get the flu shot because it will make me sick.”Can the flu shot cause the flu in otherwise healthy individuals? NO! 13
  14. 14. Influenza Vaccine Influenza – Contagious seasonal viral respiratory infection Two Immunization Methods – Injection Inactivated trivalent influenza vaccine (TIV) contains only non-infectious virus non- – Nasal Spray Live attenuated influenza vaccine (LAIV) weakened virus can’t replicate in the lungs Influenza VaccineIs it possible to get the flu if you received an influenza vaccine? YES ! Vaccine strains may not match circulating viral strains Individuals may not mount adequate immune response Takes ~ 2 weeks to mount a responseA healthy 11 year old girl comes to the health department for her vaccines. She has had all the recommended vaccines through age 4 years.What vaccines does she need today? 14
  15. 15. Concern“I heard the Meningococcal Vaccine Causes Guillain-Barre” Guillain- Meningococcemia – Bacteria causes blood infection or meningitis – A risk At i k – Children with immune-deficiencies – Healthy children < 1 yr and adolescents 15-18 yrs – Freshman living in college dorms – Recommendations – MCV4 vaccine for healthy 11-12 year olds – Booster dose at 16 yrs What is Guillain-Barre? Guillain-Guillain-BarréGuillain-Barré Syndrome (GBS) - disorder involving inflammatory de-myelination de-of peripheral nerves, characterized by the progressive, symmetrical weakness 15
  16. 16. ConcernMeningococcemia Vaccine and Guillan- Guillan-BarreFebruary 2008, > 15 million doses MCV4distributed. pVAERS reports - 26 cases of GBS within 6 wks ofvaccinationInitial data - possible small increased risk of GBSWarning added to vaccine information statementFurther research - 1.4 million patients studied andNO cases of GBS within 6 wks of vaccinationwarning about GBS removed Concern“I don’t want my child to get theMMR vaccine because I heard it causes autism” MMR VaccineMeasles – Contagious respiratory infection – 1/20 may develop pneumonia – 1/1000 may dieMumps – Respiratory virus causing fever and swollen salivary glands – Can cause orchitis in older males, encephalitisRubella – Usually mild illness (fever and rash) in children – Can cause birth defects if pregnant woman infected 16
  17. 17. Concern “Does MMR Cause Autism?”“Wakefield Study”– Andrew Wakefield, British gastroenterologist– Published in Lancet, 1998– suggested a connection between MMR vaccine, gastrointestinal symptoms, and autism– Study of 12 children with developmental delay (8 with autism) Wakefield Study FlawsVery small sample sizeNo control group– Should study prevalence of autism in vaccinated vs. unvaccinated childrenPossible bias in data collection– Endoscopic and neuropsychological assessments not blinded– Data not collected systematically or completely Wakefield StudyIn 2004, 10 of the 13 authors retracted thestudy’s interpretationIn February 2010, Lancet retracted themanuscriptIn January 2011, British Medical Journalclaimed study was fraudulent 17
  18. 18. The Lancet RetractionStudy Found to be Fraudulent The Damage… Vaccination rates dropped 80% in UK in 2003-2004 (95% needed for 2003- herd immunity) Measles epidemic in England and Wales in 2008 Parental mistrust in vaccines Resources spent on this rather than finding true cause of autism Mistrust in medical community 18
  19. 19. Why Did Parents Believe This? Study in literature must be true Signs of autism appear around the same time children receive the MMR vaccine - misinterpreted as causal relationship i i t t d l l ti hi The cause of autism is unknown MMR was something to blame Media coverage /TV shows/celebrity testimonialsRe: Airing of television show “Eli Stone” in early 2008 No Evidence that MMR Causes Autism Numerous larger studies (> 23) found NO association between MMR vaccine and autism 1 year birthday video study - signs of autism present prior to MMR In 2004, Institute of Medicine (IOM) concluded no association between MMR vaccine and autism 19
  20. 20. Reputable and Not-so- Not-so-ReputableImmunization ResourcesI i ti R 20
  21. 21. Reputable Vaccine Centers for Disease Immunization Action Coalition1-800-CDC-INFO 800-CDC- Telephone advice re: Email for vaccine Childhood Immunization Support hhs gov/nvpo National Vaccine Program National Network for Immunization Information (NNii) MI school shot TX school shot requirementsMyers MG, Pineda D. “Do Vaccines Cause That? A Guide for “DoEvaluating Vaccine Safety Concerns” 2008 Concerns” 21
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