issues associated with acceptability of viral std vaccines

Issues Associated with Acceptability of Viral STD Vaccines

Susan L. Rosenthal, Ph.D

Overview

Theoretical models of health behaviors Influences on attitudesCharacteristics of the vaccines  Review of studies using health belief

modelsFuture research questions

Theoretical Model of Health Behaviors 

Important Health Beliefs

Perceived severityPerceived susceptibility Barriers to implementing the behavior Important others’ beliefs

Health Beliefs

Perceived Severity– Seriousness of the disease– Consequences of the disease

Perceived Susceptibility – Risk of acquiring the disease– Expectation that behavior would reduce the

likelihood of harm(What will be the impact of partial efficacy?)

Health Beliefs

Barriers to Implementing the Behavior – Access– Need for shots– Concerns about real or imagined side

effectsBeliefs of Important Others

– Normative beliefs– Motivation to comply with preferences of

relevant others

Influences on Attitudes

Health Care Providers

Health Care Providers– Comfort with talking about sexuality– Knowledge about disease– Knowledge about side effects – Expectations about parental attitudes and

need for consent

Mrs. Smith, now that your daughter is 13, it’s time for her to get vaccinatedfor gonorrhea, chlamydia, and herpes

Zimet, 2000

Societal/Cultural Beliefs

Beliefs about immunization in generalRisk behavior and STDs

Societal/Cultural Beliefs

National Vaccine Injury Compensation Program– “If you believe that you or a loved one has been

injured as a result of a vaccination, we may be able to help.“

The National Vaccine Information Center – “NVIC is dedicated to the prevention of vaccine

injuries and deaths through public education”

Psychosocial/Behavioral Factors and Vaccine Effectiveness

VaccineAccepted

DiseaseIncidenceDecreased?

False Reassurancere: Target STD

FalseReassurancere: Other STDIncreased

RiskBehaviors

Zimet, 2000

Characteristics of the Vaccine

Vaccine Characteristics

Method of delivery– Shot– Frequency

EfficacyCost

HPV Vaccine Characteristics

Characteristics of the vaccine:– Cost (150, 50, free)– Efficacy (50% or 90%)– Disease targeted (genital warts, cervical cancer,

both)

– Physician recommended Results for adolescents and young women:

– Most acceptable: 90% efficacy, physician recommended, and moderately priced

– Disease target made no difference

Zimet, et al, 2000

HPV/HSV Vaccine Acceptability Among College Students

Provided reproductive, sexual, and combined cues in description of the vaccine

Cue did not predict acceptance and there was no gender/cue interaction.

Boehner, et al, 2002

Predictors of Vaccine Acceptance

HBV Immunization Among Adolescents

Predictors for adolescents’ acceptance– Perception that immunization was important to

parents

– Belief that it is important for everyone to be vaccinated

Predictors for parents’ acceptance– Perception that immunization was important to

provider

– Concern about adolescent’s risk for HBV

Rosenthal, et al, 1995

HIV Vaccine Acceptability in Adolescents

Generic HIV vaccine acceptable– Mean 5.12 out of 6

Greater vaccine acceptability associated with:– Susceptibility to HIV– Benefits of being vaccinated

Lower vaccine acceptability– Fear of vaccine causing HIV– Not being a member of risk group– Fear of needles

Zimet, et al, 1999 and Webb, et al, 1999

Herpes Vaccine Acceptability in College Students

Number (%) accepting the vaccine – 207 (40% ) would get vaccine– 211 (41%) not sure– 100 (19%) would not

Greater likelihood of acceptance – Low cost– Belief that it would work (for yes/not sure)– All teens – All sexually experienced individuals (yes/no)

Rosenthal, et al., 1999

Other Findings

Different predictors of vaccine acceptance for HPV and HSV vaccine acceptance among college students

For vaccine trial participants, acceptance of HSV vaccine was related to decreased exercise and lower alcohol use

For vaccine trial participants, acceptance of HPV vaccine was influenced by perceptions of support from church/synagogue

Chain of Vaccine Acceptance

Professional Organizations’ Recommendations

Health Care Providers

Parents

Adolescents

STD Vaccine Acceptance

Summary of STD Vaccine Acceptability Studies

Positive attitudes about STD vaccines across populations

Vaccine efficacy is important, but probably not disease targeted

Acceptability associated with positive and negative health beliefs, but less so with health behaviors

Issues for Future Research

Issues for Future Research

Efficacy– Level at which acceptance decreases – People’s understanding of partial efficacy– Physicians response in terms of

recommendations

Issues for Future Research

Access/provider issues – Enhancing access– Cost to patient – Increasing provider comfort

Universal recommendation – Developing policy to accomplish