1. Vaccine Beliefs of Parents who Oppose Compulsory Vaccination
Allison Kennedy, MPH
National Immunization Conference
May 12, 2004

2. Compulsory Vaccination
First compulsory vaccination and school laws in 19th century Massachusetts1
Have been upheld by Supreme Court (1905 Jacobson v. Massachusetts)
Modern enforcement of school laws a response to measles control efforts of the late 1970s
The first compulsory vaccination laws in the US appeared in 19th century Massachusetts regarding smallpox vaccine. Public school entry requirements soon followed.
The constitutionality of compulsory vaccination has been upheld by the Supreme Court, most notably in Jacobson v. Massachusetts in 1905, in which an adult citizen of Cambridge refused vaccination because he feared a possible bad reaction to the vaccine. He protested the law all the way to the Supreme Court, where the court ruled that the city had the right to compel vaccination for the protection of the public’s health.
As additional vaccines were licensed, laws were updated on a state-by-state basis. In more recent decades, the enforcement of school entry laws was associated with significant reductions in measles cases in the late ’70s.
(1Hinman et al., 2000)

3. Exemption Laws Medical : 50 States Religious: 48 States
Philosophical: 19 States
All 50 states offer exemption to their school entry laws, but the type of exemption offered varies by state:
Medical exemptions are available in all 50 states, and usually require the signature of a licensed physician stating that vaccination is contraindicated.
Religious exemptions are available in 48 states and the District of Columbia (all but Mississippi or West Virginia), allowing parents to opt out of vaccines for religious reasons. These laws range from strictly defined (“member of an organized religion”) to very broadly construed personal religious beliefs, in which essentially anyone that applies is granted the exemption. This often makes it difficult to categorize or distinguish between religious exemptions and the third type of exemption…
Philosophical exemptions. These are “officially” available in 19 states, and apply to parents whose personal (apart from religious) beliefs prohibit immunization. They range in ease from a signature on the back of the immunization certificate, to providing a written and notarized letter outlining beliefs. There has been some evidence that these exemptions are taken for convenience, as one study showed that states with easy to obtain exemptions had higher rates of non-medical exemption than states with difficult to obtain exemptions (Rota et al., 2001).

4. Vaccine Exemptions By State
Red= Allow philosophical exemptions
Tan= Allow religious exemptions
Gray=
Allow medical exemptions
This map contains the same information as the previous slide. States in gray have only medical exemptions, states in tan offer medical and religious exemptions, and states in red offer medical, religiuos, and philosophical exemptions to school entry. Note also that Missouri and Nebraska offer philosophical exmeptions to daycare, but not school, immunization requirements.
19 states classified as having a formal philosophical exemption for school entry: Maine, Vermont, Michigan, Ohio, Wisconsin, Minnesota, North Dakota, Arkansas, Louisiana, Oklahoma, Texas, Arizona, Colorado, Idaho, New Mexico, Utah, California, Washington, and Pennsylvania.
Source: Johns Hopkins Institute
for Vaccine Safety

5. Consequences
Several outbreaks of measles, polio and pertussis among exempt populations have been documented
In outbreak situations, exemptors are more likely than non-exemptors to get measles and pertussis2,3
Although an unimmunized child avoids the small risk of side effects from vaccination, they then risk contracting or transmitting vaccine-preventable diseases. Outbreaks of measles, polio, and pertussis have been documented among populations of religious and philosophical exemptors or non-vaccinators in the US and abroad, and in outbreak situations, exemptors are not surprisingly more likely to contract measles and pertussis than non-exemptors.
(2Salmon et al, 1999; 3Feikin et al, 2000)

6. Objectives
Determine the vaccine-related beliefs that predict opposition to compulsory vaccination among parents
Determine if availability of a philosophical exemption in a parent’s state of residence is associated with opposition to compulsory vaccination
Given the importance of school entry laws in helping to promote childhood immunization and control vaccine-preventable disease, and given the fact that, although these immunizations are often compulsory, many parents do have the option of refusal, we wanted to better understand parents who were opposed to vaccination laws for school entry.

7. 2002 HealthStyles Survey Mail panel survey (July-August, 2002)
Data weighted to U.S. Census Current Population Survey
Outcome variable: Opposition to compulsory vaccination (dichotomized 5-point Likert scale)
HealthStyles is a followup to the annual ConsumerStyles survey. ConsumerStyles is drawn from a mail panel of 500,000 households that have perviously agreed to participate in occasional surveys. 10,000 participants received the 2002 ConsumerStyles survey, and 6065 responded. These respondents were then sent the Healthstyles survey. The data were then weighted to the US population using the 2000 CPS. Our analysis was restricted to the subsample of respondents who has at least one child aged 0-18 (n=1527).
Children should be allowed to go to public school even if they are not vaccinated. Parents who strongly agreed or agreed were considered “opposed” to compulsory vaccination. Parents who were neutral, disagreed, or strongly disagreed were considered “supportive” of compulsory vaccination.

8. Analysis
Demographic, belief, and behavior variables chosen and collapsed or dichotomized to increase power
Chi square tests of association used to determine variables for inclusion in a logistic regression model
Logistic regression model used to calculate adjusted odds ratios
Looked at demographic variables (parent age, race, gender, education, income, and household size), as well as vaccine safety and necessity beliefs, and vaccine behavior (intention to vaccinate youngest child).

9. Analysis
Classified states as either allowing or not allowing philosophical exemption
Excluded states with de facto and daycare only exemptions

10. Survey Participants Who Oppose and Support Compulsory Vaccination
Variable
n (%)*
Compulsory vaccination for school entry:
Oppose
188 (12)
Support
1339 (88)
There were 4397 respondents to HealthStyles, for an overall response rate of 72%.
*Weighted subsample of parents of children aged 0-18; n=1527

11. Results of Bivariate Analysis: Demographics
No difference:
Gender
Age
Education
Significant difference:
Household size
Respondent race
Household income
Availability of exemption

12. Household Size
Statistically significant difference at p<0.05 level.

13. Respondent Race
Statistically significant difference at p<0.05 level.

14. Household Income
Statistically significant difference at p<0.05 level.

15. Availability of Philosophical Exemption
Statistically significant difference at p<0.05 level. Again, respondent gender, age, and education level were similar for both groups.

16. Results of Bivariate Analysis: Belief and Behavior
Significant difference:
Concern that vaccine-preventable diseases (VPD) are not serious/not likely to be encountered
General safety of vaccines
Children get too many vaccines in the first two years of life
The body can protect itself from VPD
Vaccines are necessary/important to health
Plan for immunizing youngest child
The only belief/behavior question that was not similar across the two groups was the statement: Children get more vaccines than are good for them.

17. General safety of vaccines for children
Statistically significant difference at p<0.05 level.

18. Children get too many vaccines in the first two years of life
Statistically significant difference at p<0.05 level.

19. On its own, the body can protect itself from vaccine-preventable diseases
Statistically significant difference at p<0.05 level.

20. Vaccines are necessary to prevent certain diseases
Statistically significant difference at p<0.05 level.

21. How important do you think vaccines are to the health of children?
Statistically significant difference at p<0.05 level.

22. What is your plan for immunizing your youngest child?
Statistically significant difference at p<0.05 level.

23. Do demographics, beliefs and behaviors predict opposition to compulsory vaccination?

24. Adjusted Odds Ratio Variable Adjusted OR 95% CI Income $0-$24,999
2.321
$25,000-49,999
1.283
$50,000-74,999
0.975
$75,000 and over
1.000
***
Plan for immunizing youngest child
Will not receive all
4.287
Has had/will have all

25. Adjusted Odds Ratio Variable Adjusted OR 95% CI
The body can protect itself from vaccine-preventable diseases
Agree
2.268
Disagree
1.000
***
Importance of vaccines to child’s health
Not/somewhat important
1.782
Important/very important
Vaccines are necessary to prevent certain diseases
1.692

26. Is availability of philosophical exemption associated with parental opposition?

27. Adjusted Odds Ratio Variable Adjusted OR 95% CI
State of residence has philosophical exemption law
Yes
1.672 No
1.000
***

28. Summary
The final multivariate model showed that opposed parents were more likely to:
be of lower income
believe the body can protect itself without vaccines, and believe that vaccines are not important or necessary to a child’s health
report that their youngest child would not be fully vaccinated
live in a state that offers philosophical exemption to vaccination

29. Limitations
Small sample size of parents opposed to compulsory vaccination may have failed to detect significant differences
Cannot assume exemptor status based on opposition to compulsory vaccination
Cross-sectional survey
Generalizability of HealthStyles
We did collapse or dichotomize our variables to help increase statistical power. This may have resulted in an inability to detect more subtle differences or trends among parents.
In addition, we cannot assume that a respondent’s theoretical opposition to compulsory vaccination will translate into a vaccine exemption. However, our opposed parents were more likely to report that their youngest child would not be fully vaccinated and live in a state where philosophical exemptions are available.
Because this is a cross-sectional survey, we cannot determine causality: whether state laws helped shape the beliefs of parents, or whether the beliefs of parents led them to advocate for a change in the law, and this is an area which may require further study.
Although the HealthStyles survey does not use a probability sampling methodology, the data are weighted to reflect the US population, and a comparison with the BRFSS survey showed high correlation between similar items on both surveys (Pollard, 2002).

30. Conclusions
Parents who oppose compulsory vaccination are less likely to believe that vaccines are important to their child’s health
These parents are also more likely to live in states offering philosophical exemptions, and to report that their children will not be fully immunized
As we might expect, the vaccine beliefs of parents opposed to compulsory vaccination are different from the beliefs of parents who support compulsory vaccination. While this fact alone may not be surprising, it is important to remember that these parents also were more likely to report an intention not to fully vaccinate their children, and they lived in states where that option is available to them. Health education can play an important role in ensuring that parents who refuse immunizations are doing so in an informed manner, and not because of convenience or misperceptions about the risks of vaccines or vaccine-preventable diseases.

31. Future Studies
Assessment of demographics and beliefs of parents who have considered or filed for religious or philosophical exemptions
Follow survey results over time to detect trends in exemptions and beliefs of parents, as well as exemption rates
Development and evaluation of educational materials to address the concerns of parents who consider exempting or opting out of vaccines
To ensure that vaccine refusal is done in an informed manner, with a complete understanding of the risks to the individual and community.

32. Acknowledgements Deb Gust Cedric Brown Bob Chen Dan Salmon
Porter Novelli