Strategies for Development and Implementation of Viral STD Vaccine Programs: Inventing an Effective Vaccine is Not Enough

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Strategies for Development and Implementation of
Viral STD Vaccine Programs Inventing an
Effective Vaccine is Not Enough

• John M. Douglas, Jr., MD
• Denver Public Health

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Innovations in Vaccine Delivery the 20th
Century
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Innovations in Vaccine delivery the 21st
Century (public health officials trying to meet
teens on their own turf)
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Implementation of Hepatitis B Vaccine

• Proven efficacious in large trials among
  neonates, MSM, IDU in late 70s-early 80s
• Efficacy 3 doses 95, 2 doses 75, 1 dose 50
• The chronology
• licensed in U.S.1982, recommended for high-risk
  groups
• mandated for HCWs 1989
• routine infant immunization 1991
• routine for young adolescents 1994
• routine for STD clinics, 1998
• still no comprehensive older adolescent/adult
  program (the missed generation) in the U.S.

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Difficulties in Reaching the Highest Risk Groups
MSM

• 3432 MSM 15-22, 7 US cities in Young Mens Health
  Survey, 1994-98
• Prior immunization in 9
• Prior infection in 11 (2 in 15 yo, 17 in 22
  yo)
• Of susceptibles, 96 had regular source of health
  care or access for HIV/STD testing
• (MacKellar DA. AJPH 2001 91 965)

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Missed Opportunities for HBV Immunization

• CDC HBV sentinel surveillance, 1996-8
• of acute HBV cases with prior encounters
• known infected contact 9
• hx STD Rx or incarceration 55

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Difficulties in Targeting High-risk
Adolescents/Adults

• 1997 survey of 65 STD programs and 89 STD clinics
• 21 of programs had HBV vaccination policies 45
  of clinics had HBV vaccine policies (mostly VFS)
• Issues funding for vaccine resources for
  pre-vaccination counseling, vaccine
  administration, and client tracking
• (Wilson BC, STD 2001 28148)

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STD clinic-based HBV Immunization the San
Francisco Experience, 1990

• Willing to receive free vaccine 44
• Already exposed 28
• No. receiving HBV doses
• 0 56
• 1 22
• 2 8
• 3 14
• (Weinstock. AJPH 1995 85 846)

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STD clinic-based HBV Immunization the Denver
Experience, 1999-2001

• No. eligible patients 5047
• Willing to receive free vaccine 60
• No. receiving HBV doses
• 0 70 (40 refused, 30 no show)
• 1 15
• 2 8
• 3 7
• Overall protection 21
• (Subiador, 2002 STD Conference)

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Age-related seroprevalence of HSV-2 and HPV-16 in
the population

• Age HSV-2 HPV-16
• 12-19 5.6 5.1
• 20-29 17.2 14.6
• 30-39 27.8 14.7
• 40-49 26.6 17.0
• 50-59 25.1 10.6
• (Fleming. NEJM 1997 337 1105 Stone 2000 Nat
  STD Prevention Conf)

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Age-related HSV-2 seroprevalence among STD Clinic
Populations (Gottlieb, data from Project RESPECT)
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Strategies for Reaching Persons with STD Vaccines
Before Young Adulthood

• Childhood immunization
• Opportunistic immunization of sexually active
  adolescents (eg, family planning, STD clinics)
• Routinely recommended immunization of
  pre-adolescents
• primary health care providers
• school-based programs

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Chain of vaccine program implementation

• Professional organization recommendation
• Infrastructure for immunization
• routine well-adolescent visits
• school-based clinics
• Support by payors
• Legislation (e.g., school entry requirements)

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Routine adolescent immunization (AI) visits

• Recommended in 1996 by ACIP, AAP, AMA, AAFP
• Intent establish a routine visit to allow
  improve immunization coverage for VZV, MMR, DT,
  and HBV, and provide other recommended prevention
  services

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School-based clinics for adolescent immunization

• Broad access/coverage 99 of children enrolled
  until age 13, including those with no other
  sources of preventive care
• Full-scale school support
• publicity through school
• incentive programs
• peer pressure
• teacher and prinicipal support
• education through health classes
• organized school vaccination days
• More effective tracking and reminders
• Student parent convenience
• (Middleman. J Adol Hlth 2000 26 320)

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Completion of HBV Immunization in Adolescents

• Statewide targeted HBV vaccine program for 10,716
  adolescents (11-18) 1996-97 in Oregon
• Completion rates within the school year
• school-based centers 91
• LHD outreach to schools 85
• LHD clinics 64
• (Nystrom. J Adol Hlth 2000 26320)

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Middle School-based HBV Immunization the Denver
Experience, 1996-7

• Partnership with local MCOs to reimburse school
  clinics for HBV immunization
• No. students 4543
• Consented/exempted 74/12
• No. receiving HBV doses
• 0 1
• 1 5
• 2 8
• 3 85
• More cost-effective than network HMO (31 vs.
  68/dose not including indirect work-loss costs)
• (Deuson AJPH 1999 89 1722)

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Mandated HBV Immunization

• Colorado school entry law
• Effective August, 1997, three doses of HBV
  vaccine required for entry into 7th grade
• In subsequent years, the law extended to 8th and
  then 9th grade for that cohort
• Goal In six years (May, 2003) all students
  between kindergarten and 12th grade will be
  immunized against HBV
• Currently, approximately 45 states have
  regulations mandating HBV vaccine for school
  entry
• Requires collaboration between state/local HD,
  schools, local NGOs, health care providers
• May benefit from model legislation templates

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Adolescent Immunization the trickle-up effect
among Denver STD clinic patients

• Year History of HBV vaccine
• 1999 48
• 2000 58
• 2001 72
• (Subiador, 2002 STD Prevention Conference)

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Other issues for STD vaccine delivery programs

• Willingness of parents to consent to vaccines
• Willingness of payors to cover vaccines
• Willingness of boards of health to require
  vaccines
• Willingness of school boards to allow STD
  vaccines in school-based clinics
• Should the STD nature of the infections be
  downplayed (eg,vaccines to prevent birth
  defects or cervical cancer naming
  issues--CIN-VAX)

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Thoughts for the Future

• lack of openness and mixed messages regarding
  sexuality create obstacles to STD prevention for
  the entire population and contribute to the
  hidden nature of STDs. The Hidden
  Epidemic, 1997
• Our ultimate ability to broadly immunize young
  adolescents against infections STD will depend on
  societal ability to acknowledge and discuss
  adolescent sexuality

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Implementation of STD vaccines Issues beyond
delivery systems

• Role for serologic pre-screening (HSV-1 or -2,
  various HPV types)
• Impact on disease presentation (eg, more
  asymptomatic and less easily recognized)
• Impact on other screening programs (eg, cervical
  cytology)
• Defining the need for booster doses

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Other issues for STD vaccine delivery programs

• Willingness of parents to consent to vaccines
• Willingness of payors to cover vaccines
• Willingness of boards of health to require
  vaccines
• Willingness of school boards to allow STD
  vaccines in school-based clinics

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Hepatitis B Vaccine Reasons for Failure of
Risk-Targeted Programs

• Adult providers not vaccine-attuned
• High-risk persons (and some providers) didnt
  understand/care about long-term HBV consequences
• High-risk groups hard to access, require risk
  factor elicitation, 10-30 already infected
• No payor for high-cost vaccines
• Limited infrastructure to deliver 2 follow-up
  doses of vaccine over 6 months and limited
  attention to partial benefit (1 dose 50, 2 doses
  85)
• AIDS effect attention distracted from HBV and
  in highest risk groups, those with ongoing risky
  behavior likely to contract and die of HIV before
  vaccine benefit realized

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Value of School-Based Immunization Programs

• Broad access/coverage 99 of children enrolled
  until age 13, including those with no other
  source of preventive heath care
• Convenient for parents students and can reduce
  costs of transportation and lost parent work time
• Efficient for large MCOs to deliver contracted
  vaccine benefits
• Vaccine programs can complement general sexual
  health curriculum
• May be convenient for other adolescent prevention
  activities