Can Emphasizing Herd Immunity Influence Parents' Intentions To Vaccinate Their Children?

Theoretical Background and research questions/hypothesis: Information emphasizing the benefits of vaccines to others beyond the vaccine recipient has been linked to increased vaccine intentions in adults. However, no study has tested whether this pattern holds true for parents when they are making vaccine decisions for their children. We sought to determine whether presenting information that emphasizes the various benefits of the measles, mumps, and rubella (MMR) vaccination to the child recipient versus to others beyond the child recipient (i.e., society) differentially impacts parents' intentions to have their infant vaccinated for MMR.

Methods: Parents (N=802) of infants younger than 12 months of age completed a national, online survey. They were presented with 1 of 4 messages about the MMR vaccine: 1) standard information from the CDC; 2) standard information and information concerning the MMR vaccine's benefits to the child; 3) standard information and information concerning the MMR vaccine's benefits to society; 4) standard information and information concerning the MMR vaccine's benefits both to the child and to society. Parents then indicated the likelihood of vaccinating their infants for MMR on an 11-point scale anchored at 0 (extremely unlikely) and 100 (extremely likely) in increments of 10. We also measured general attitudes/worries about vaccination and medical trust. We used linear regression models to analyze the data.

Results: Parents with generally positive vaccine attitudes, high levels of medical trust, or low levels of fear that autism is caused by the MMR vaccine reported higher vaccine intentions (p<0.01), compared to those with negative vaccine attitudes, low medical trust, or high levels of fear that autism is caused by the MMR vaccine. Compared to receiving only standard MMR vaccine information from the CDC, respondents who received either 1) additional information concerning the vaccine's benefit to the child or 2) additional information concerning the vaccine's benefits both to the child and to society indicated greater intentions to vaccinate their infant for MMR (p=0.01 and p=0.03, respectively). Additional information focusing on the MMR vaccine's benefits to society was not related to increased vaccination intentions compared to standard CDC information only (p=0.97, ns).

Conclusions: Unlike patterns demonstrated in previous literature focusing on adult populations, emphasizing information about a vaccine's benefits to society did not increase vaccine intentions among parents for their infants. Parents reported highest levels of MMR vaccine intentions for their infants when they received standard CDC information about the MMR vaccine coupled with information highlighting the benefits of the MMR vaccine directly to the child.

Implications for research and/or practice:  Results suggest that pediatric health care providers wishing to increase MMR vaccination rates should focus on emphasizing the benefits of vaccination to the child directly. Additional mention of societal benefits appears to have no added value but also does not interfere with information highlighting benefits directly to the vaccine recipient.