New research from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London has assessed parental preference for a mandatory childhood vaccination scheme and finds that, when rating different options for a mandatory vaccination scheme, the incentives for vaccinating, and penalties for not vaccinating, were the most influential factors in parents’ decisions.

Rates of uptake for most child vaccines have been declining in recent years, raising questions as to how this can be improved. While there aren’t currently any plans to introduce a mandatory vaccination scheme in England, the study, published in The Lancet Regional Health – Europe, explored parental preferences for a range of factors that might be considered by policymakers, in the event that childhood vaccination were to be made mandatory.

The investigators explored the opinions of 1001 parents of children aged 5 years and under. Participants were shown a series of comparisons of hypothetical mandatory vaccination schemes and asked which they preferred. Schemes differed by:

• Which vaccine would be made mandatory (6-in-1 or MMR)
• What age vaccination would be mandatory in (2 years and above or 5 years and above)
• Who could opt out of the scheme (medical exemptions only or medical and religious belief exemptions)
• The type of incentive for vaccination offered (a £130 cash pay out to the parent per vaccine dose, a £130 voucher for the child per vaccine dose, or no incentive)
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• Whether there should be a penalty for not vaccinating (a £450 fine for each dose missed, the child being unable to attend school or day-care if unvaccinated, or the parent not being able to claim Child Benefits if the child is not vaccinated)
• Availability of a compensation scheme for severe adverse side effects (offered or not offered). Parents were shown different combinations of these factors, and their relative preferences for each factor were calculated.

The results showed that the most influential factor in parents’ decisions was being paid an incentive (either to the parent or the child). Participants were also strongly influenced by the penalty for not vaccinating, with parents preferring schemes where unvaccinated children could not attend school or day care, and for those withholding financial benefits for parents of unvaccinated children, compared to receiving a fine.

Parents also preferred schemes that offered a compensation scheme, mandated vaccination in children aged two years and above, mandated the 6-in-1 vaccine, and that offered only medical exemptions. However, patterns of preferences differed by attitudes towards vaccination.

Dr Louise Smith, the study’s Primary Investigator said, “Vaccines are an effective means of containing the spread of highly contagious illnesses, but vaccination rates have been falling. Our intention was to explore parents’ preferences so that their views could be taken into account in the event that a mandatory vaccination scheme is proposed.”

“Our findings present a diverse picture that reflect the complexity surrounding this issue. While our results suggest that if a mandatory vaccination scheme were suggested, parents prefer schemes that offer direct financial rewards, preferences may not indicate that someone feels a scheme is acceptable.”

Dr Ben Carter, the study’s last author from King’s IoPPN said, “Making vaccines mandatory can have unintended negative consequences, including having the potential to make vaccination attitudes more negative in some people. Therefore, any proposal of such a scheme needs to be made with caution. Care also needs to be taken to ensure that schemes do not disproportionately affect those who are from lower income backgrounds.”