Reflections of a Vaccinologist: Lessons Learned About What We Can Do to Improve Trust in Vaccines and Vaccine Programs

"...trust in vaccines is essential for the success of immunization programs."

Motivated by the belief that public trust in vaccines can be improved by learning from past mistakes, vaccinologist Neal A. Halsey begins this article with some examples from efforts around the oral polio vaccine (OPV). Mistrust of vaccines and immunisation programes has resulted in vaccine refusal and disruption of immunisation efforts, as when suspicion about OPV in Nigeria stopped polio vaccination for 13 months in 1 district and enabled the exportation of wild poliovirus (WPV) to at least 26 countries. In the United States (US), OPV caused 6 to 10 cases of vaccine-associated paralytic polio each year in the 1990s, until it was replaced by the safer inactivated polio vaccine (IPV), enhancing public confidence in vaccines.

Lessons learned from a resurgence of measles in the US in 2014/2015 included the public understanding that unvaccinated individuals pose serious risks to children who cannot receive vaccines and that unvaccinated children can grow up to be susceptible adults and contribute to outbreaks of disease in settings such as Disneyland (a theme park in California, US, where an outbreak occurred). Halsey's own experience witnessing deaths from measles in Nicaragua and North Dakota, US, introduced him to the power of epidemiology to answer public health questions. Halsey points out that "We cannot expect the general public to recognize bad science, but we can do a better job of reporting in medical journals...Reports of unexpected serious illnesses after vaccines have resulted in the termination of national immunization programs....Instructive case reports are an integral part of our medical education and are included in highly respected journals. Case reports are a form of storytelling, which has been used for teaching since the beginnings of recorded time in cultures throughout the world." According to Halsey, developing standard guidelines for reporting causality assessment in case reports could help educate physicians and prevent future unnecessary concerns based on false assumptions of causal relationships.

Halsey describes the 2009–2010 H1N1 influenza immunisation campaign, which "stimulated interest in vaccine safety and the need to coordinate safety information. The National Vaccine Program Office [in the US] established a committee to review studies from multiple federal agencies....This forum allowed for open discussions and sharing of study methods and preliminary data as the response evolved. Although several signals of possible relationships between adverse events and the vaccines were identified and openly discussed..., a standing committee should be maintained to provide a forum for addressing questions about vaccine safety and helping to address these questions in a timely manner as they arise."

On the issue of nonmedical exemptions from school requirements for immunisation, Halsey quotes Larry Gostin, a public health attorney and ethicist, who stated, "Harsh penalties could fuel public opposition to vaccine policy. The wiser course could be to require a rigorous process for claiming the exemption, relying on behavioral economics to encourage compliance." Halsey suggests that all physicians who participate in possible changes to legislation should consult a review of religious concerns regarding immunisations by John Grabenstein. "This information should be shared with families who raise religious concerns about these vaccines."

A poll in August 2014 revealed that 59% of US persons aged 18-29 years believe that immunisations should be mandated, and that figure increased with age to 79% for persons aged 65 years or older. This may be due to the fact that older individuals are more likely to be familiar with the diseases against which vaccines protect, which influences their beliefs. "We have a great deal of educating to do with regard to the risks of diseases and the safety of vaccines in young parents."

In concluding, Halsey stresses that increasing trust in vaccines "does not mean that we should not talk about safety issues. Parents are getting information that needs to be addressed. We need to acknowledge when mistakes are made and when safety issues have not been detected in prelicensure studies. We need to educate people about the strengths of our vaccine safety systems, and we need to provide sufficient support to make sure that these systems are robust and can address key questions. The public needs to know that we make vaccines as safe as possible."