The development of new and more effective vaccines has had a major impact on childhood health over the past 50 years. The tremendous reduction in morbidity and mortality from infectious diseases during the vaccine era is a hallmark of the effectiveness of this singular public health effort.1 During the early 1950s, there was a major effort to develop a new polio vaccine and parents were pleased when it was accomplished. However, currently physicians are regularly confronted by increasing numbers of parents who are hesitant about accepting vaccines or who refuse some or all of them for their children.2 Although the underlying desire of parents to protect their children from harm has not changed, it has shifted from a demand for new and improved vaccines to a hesitancy about using them even though the goal of vaccine development has been, and continues to be, the prevention of serious illness. The increasing hesitancy seen in recent years presents a unique challenge to the practicing pediatrician who shares the goal of improving children's health with parents but who must also counter such hesitancy.
Vaccine Confidence and Hesitancy
The efficacy of modern vaccine programs can be seen in the reduction of rates of once pervasive bacterial and viral diseases, such as Haemophilus influenzae type b and measles.3Table 1 demonstrates the significant decrease in annual cases of vaccine-preventable diseases after vaccine introduction.4,5 Despite these successes, outbreaks of measles and pertussis continue to occur in the United States, often occurring in populations with higher than average rates of vaccine refusal.6 Although most parents follow the immunization schedule recommended by the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP), some parents delay vaccines or refuse some or all of the vaccines. As defined by the World Health Organization, “vaccine hesitancy” refers to delay in acceptance or refusal of vaccines despite availability of vaccine services.7
Comparison of Annual Cases of Vaccine-Preventable Diseases Before and After Vaccine Introduction
A national telephone survey demonstrated that approximately 3% of parents with children age 6 to 23 months had refused all vaccines and that about 19% had refused one or more vaccines.8 In 2006, the AAP surveyed pediatricians and found that 74% of pediatricians reported having one or more parents in their practice refuse at least one vaccine for their children during the previous year; by 2013, that number increased to 87%.9,10 Parents most often refused a vaccine because of safety concerns, either general (73%) or specific concerns about thimerosal or a link with autism (74%).9 However some parents (63%) refused vaccines because of a belief that immunizations are not necessary or that children experience too much discomfort (42%) from immunizations.9 Parents may also refuse vaccines because they believe that vaccines are not studied adequately prior to licensure, or they believe that vaccines are less “natural” than the disease itself. Finally, some parents express distrust of the government and pharmaceutical companies who recommend and produce vaccines.8,11–13
Although the overall rate of vaccine refusal by parents is low, rates vary among different socioeconomic and geographic groups, leading to clustering of vaccine-hesitant parents in some communities.11,14 One reason for the increase in rates of vaccine refusal may be due to laws allowing for “personal belief” exemptions from vaccination.15 Typically, children entering school are legally required to be fully immunized; however, in some states parents are able to refuse vaccines and still enroll their children in school based on such exemptions.16 Areas with high rates of these nonmedical exemptions have been associated with outbreaks of vaccine-preventable diseases.6,14 This clustering of unimmunized children can lead to an increased risk of resurgence of vaccine-preventable diseases in some communities. Pediatricians should be well versed in reasons why parents may refuse or delay vaccines so that they can address their concerns and work toward improving vaccine uptake in compliance with the ACIP and AAP vaccine schedule.
Vaccine Development and Safety Monitoring
Vaccine development is a time consuming and thorough process aimed at optimizing safety and efficacy before vaccine licensure. The Centers for Disease Control and Prevention's (CDC) “The Journey of Your Child's Vaccine” provides a pictorial description of the vaccine development process for parents.17
Prior to development of a vaccine, scientists work to identify correlates of immunity for a disease and the specific antigens that confer immunity to that disease.18,19 Once these antigens are identified, preclinical studies are done in cell culture, tissue culture, and animals to assess the safety and immunogenicity of these antigens. If these studies are successful, a sponsor must submit an Investigational New Drug (IND) application to the US Food and Drug Administration (FDA).19 The IND includes detailed information about the vaccine, the manufacturing process, safety, quality control measures, immunogenicity, and proposed protocol for human studies.19
The development of any drug, including vaccines, in the US requires three phases of testing in humans prior to licensure and marketing.19 Phase I studies assess safety and immunogenicity and are performed in a small number of human participants.19 During phase II, hundreds of human participants partake in studies to determine optimal vaccine dosage.19 After these studies are completed, phase III studies enroll many more participants in further safety and immunogenicity studies prior to licensing.19 The FDA closely monitors these phases and can stop studies or request more information if there are concerns about safety or efficacy. After these phases are completed successfully, the sponsor then submits a Biologics License Application to a review team at the FDA.19 During this process, the FDA not only reviews the vaccine data but also visits the site where the vaccine will be manufactured. If the FDA approves of the vaccine, then it is licensed for use.
Vaccine-safety monitoring does not end with licensure. There are multiple mechanisms for further monitoring of vaccines. Phase IV (postmarketing) trials are sometimes conducted by vaccine companies to further assess adverse effects and to better understand efficacy.20 Additionally, the FDA and CDC established the Vaccine Adverse Even Reporting System (VAERS) in 1990 to analyze any reported adverse events after vaccine administration. The CDC also conducts postlicensure monitoring through the Vaccine Safety Datalink, which collects vaccine-related information from nine health care organizations that provide care to millions of people in the US, as well as from VAERS reports.21 Rates of adverse events that occur in people who are vaccinated are compared to rates of adverse events that occur in a similar population of people who are unvaccinated to determine if these adverse events may be related to the vaccine.21
Addressing Vaccine Hesitancy in Clinical Practice
Providing vaccine information is a time-consuming part of daily pediatric practice, and the effort required has increased over the past years due to both the greater number of vaccines recommended for children and the increased levels of concern about vaccine safety, efficacy, and necessity demonstrated by parents. Kempe et al.22 surveyed physicians and found that more than one-half of all pediatricians spend 10 to 19 minutes discussing vaccines with individual parents, and that 8% of them report spending more than 20 minutes addressing parental concerns. The burden of spending this time was noted to have the potential to adversely impact pediatricians' job satisfaction, especially when these discussions are repeated at successive visits with the same hesitant parents. This additional time addressing concerns is not reimbursable in most cases; the time spent in addressing these concerns takes away from the time available to provide care for other patients, and thus may have adverse financial consequences on a pediatric practice.
Nevertheless, the single most important factor in gaining parental acceptance of vaccines remains the one-on-one contact with an informed, caring, and concerned pediatrician.23 In one study,13 nearly 80% of parents stated that their decision to vaccinate was positively influenced by their primary care provider. That study concluded, “…health care providers have a positive influence on parents to vaccinate their children, including parents who believe that vaccinations are unsafe. Physicians, nurses, and other health care professionals should increase their efforts to build honest and respectful relationships with parents, especially when parents express concerns about vaccine safety or have misconceptions about the benefits and risks of vaccinations.”13 A well-informed pediatrician who effectively addresses parental concerns and strongly supports the benefits of vaccination has enormous influence on parental vaccine acceptance.
Because adolescents may not present for routine preventive care visits, poor adherence to the adolescent immunizations schedule is a growing area of concern in pediatrics.24 In one study, many parents of children who are unvaccinated reported that their pediatrician did not provide recommendations for immunizations at adolescent well-child checks.25 Of those who reported not receiving a recommendation, their number one reason for not vaccinating their child was that their provider did not recommend the vaccine. In part this may be due to missed opportunities to promote vaccination at sick visits.25 Pediatricians should make a specific effort to encourage vaccination among adolescents at all types of visits. An increasing proportion of parents have unique concerns about the human papilloma virus (HPV) vaccine related to safety and necessity of vaccine prior to onset of sexual activity;26 therefore, it is crucial for providers to be familiar with the data demonstrating that the vaccine is safe and most effective when given prior to onset of sexual activity so that they can comfortably communicate with parents.
Before discussing different approaches to addressing parental concerns, the pediatrician needs to be cognizant of the parents' concerns and the reasons for them and should acknowledge these concerns in an accepting and nonjudgmental manner. Doing so demonstrates that the physician is attentive to the parents' concerns, and provides the opportunity to address these concerns openly and forthrightly, while providing accurate and timely information on vaccine safety and efficacy.27,28 Additionally, it is important to remember that, even in the face of significant disagreement about vaccination, pediatricians and parents remain in agreement about wanting the best for the health and welfare of the child.
The ultimate message that should be communicated to all parents is that “vaccines are safe and effective, and serious disease can occur if your child and family are not immunized.”2 There are many different techniques for communicating this message; however, research on these techniques demonstrates varying degrees of effectiveness. For example, Nyhan et al.29 studied the relative likelihood of parental acceptance of the measles, mumps, rubella (MMR) vaccine by presenting groups of parents with four different messages: evidence of the lack of vaccine association with autism, information about the dangers of the diseases prevented by the MMR vaccine, visual images of children affected by these diseases and a dramatic audio narrative about an infant who almost died of measles, as well as a group receiving no interventional message. None of the interventions increased parental intent to vaccinate a future child with MMR vaccine, leading to the conclusion that current public health communications about vaccines may be ineffective. Although this study was limited in that it did not include direct one-to-one communication between the parent and the physician, it did suggest that some commonly used techniques are lacking in efficacy and impact.
This observation does not, however, mean that there is nothing that the clinician can do to impact the intent of parents to vaccinate their children. A presumptive delivery strategy, in which indicated vaccines are presented as being necessary to provide optimal disease prevention, and need to be given at the current visit, led to many parents accepting the provider's vaccine recommendations.30 Another study of recorded physician conversations about HPV vaccination demonstrated that pediatricians frequently gave inconsistent messages about the HPV vaccine, but that when pediatricians began the conversation with presumptive language, assuming that parents would vaccinate their child, parents were more likely to accept the vaccine.31 This approach may be seen as failing to include the parent in the decision-making process. However, Hofstetter et al.32 recently found that pediatricians who used a presumptive delivery for influenza vaccine and who pursued the vaccine recommendation, were more likely to have parents accept influenza vaccine without negatively impacting the parent's reported visit experience. This approach might not be effective in all situations, but it does show that the provider is confident about the need for and efficacy of the vaccines being recommended.
Attaining this level of confidence also requires specific and detailed training of the provider, especially as the incidence of vaccine-preventable diseases has decreased over recent decades. Whereas pediatricians who trained years ago have first-hand experience with children's illnesses in both the pre-vaccine and post-vaccine eras, more recently trained physicians may not be able to offer such compelling personal stories;33 this is equally true about parental experience. Whereas grandparents may recall the pre-vaccine era, current parents were likely raised in a time where they or their peers did not experience these diseases. Thus, even as the incidence of these diseases decreases, training programs must insure that the diseases that vaccines prevent are not forgotten.
Because the pediatrician in the context of a trusting relationship with parents is the most important factor overall in parental acceptance of vaccines, personalization of the messages about vaccine safety and efficacy may be another compelling method to impact parental decisions. First-hand stories about vaccine-preventable diseases in one's practice conveys a strong message about how these diseases affected children, families, and pediatricians in years past, and can communicate both the impact of these diseases and the pediatrician's desire not to have to treat such diseases again. In addition, physicians relating that they have immunized their own children, their grandchildren, or themselves is a compelling message that they are confident in the safety and efficacy of vaccines.
Other techniques, including concurrent recommendation of multiple vaccines, continued pursuit in the face of refusal, and parent-centered motivational interviewing have also been studied,32 and suggest that there are several communication pathways that can be followed when discussing vaccines with parents who are hesitant or uncertain. However, definitive assessment of these techniques remains elusive, and they should be considered as options that may be appropriate to specific situations and may be used as a part of discussions with parents.34
Ultimately, the goal of both parents and pediatricians is to optimize the health of all children, and timely administration of vaccines is a critical tool to achieve this goal. Keeping this goal in mind is crucial when dealing with parents who are hesitant or concerned about vaccinating their children, as most parents are not opposed to vaccines but are instead seeking the pediatrician's guidance about the issues involved, beginning with the number of vaccines recommended, the need for these vaccines, and their safety and efficacy. Pediatricians who listen and respond to a parent's concerns, and who can provide current evidence-based information supporting the need for vaccination are in the unique position to be able to both improve children's health and strengthen the bond between themselves and the families for whom they provide care.
- Phadke VK, Bednarczyk RA, Salmon DA, Omer SB. Association between vaccine refusal and vaccine-preventable diseases in the United States: a review of measles and pertussis. JAMA. 2016;315(11):1149–1158. doi:. doi:10.1001/jama.2016.1353 [CrossRef]
- Edwards KM, Hackell JMCommittee on Infectious Diseases; Committee on Practice and Ambulatory Medicine. Countering vaccine hesitancy. Pediatrics. 2016;138(3):e20162146. doi:. doi:10.1542/peds.2016-2146 [CrossRef]
- Andre FE, Booy R, Bock HL, et al. Vaccination greatly reduces disease, disability, death and inequity worldwide. Bull World Health Organ. 2008;86(2):140–146. doi:10.2471/BLT.07.040089 [CrossRef]
- Roush SW, Murphy TVVaccine-Preventable Disease Table Working Group. Historical comparisons of morbidity and mortality for vaccine-preventable diseases in the United States. JAMA. 2007;298(18):2155–2163. doi:. doi:10.1001/jama.298.18.2155 [CrossRef]
- Adams DA, Thomas KR, Jajosky RA, et al. Summary of notifiable infectious diseases and conditions - United States, 2014. MMWR Morb Mortal Wkly Rep.2016;63(54):1–152. doi:. doi:10.15585/mmwr.mm6354a1 [CrossRef]
- Feikin DR, Lezotte DC, Hamman RF, Salmon DA, Chen RT, Hoffman RE. Individual and community risks of measles and pertussis associated with personal exemptions to immunization. JAMA. 2000;284(24):3145–3150. doi:10.1001/jama.284.24.3145 [CrossRef]
- World Health Organization. Immunization, vaccines and biologicals. http://www.who.int/immunization/sage/sage_wg_vaccine_hesitancy_apr12/en/. Accessed August 9, 2018.
- McCauley MM, Kennedy A, Basket M, Sheedy K. Exploring the choice to refuse or delay vaccines: a national survey of parents of 6- through 23-month-olds. Acad Pediatr. 2012;12(5):375–383. doi:. doi:10.1016/j.acap.2012.06.007 [CrossRef]
- American Academy of Pediatrics. Periodic survey #66 pediatricians' attitudes and practices surrounding the delivery of immunizations. https://www.aap.org/en-us/professional-resources/Research/Pages/PS66_Executive_Summary_PediatriciansAttitudesandPracticesSurroundingtheDeliveryofImmunizationsPart2.aspx. Accessed August 9, 2018.
- Hough-Telford C, Kimberlin DW, Aban I, et al. Vaccine delays, refusals, and patient dismissals: a survey of pediatricians. Pediatrics. 2016;138(3):e20162127. doi:. doi:10.1542/peds.2016-2127 [CrossRef]
- Gust DA, Darling N, Kennedy A, Schwartz B. Parents with doubts about vaccines: which vaccines and reasons why. Pediatrics. 2008;122(4):718–725. doi:. doi:10.1542/peds.2007-0538 [CrossRef]
- Dube E, Vivion M, Sauvageau C, Gagneur A, Gagnon R, Guay M. Nature does things well, why should we interfere?: vaccine hesitancy among mothers. Qual Health Res. 2015;26(3):411–425. doi:. doi:10.1177/1049732315573207 [CrossRef]
- Kennedy A, Basket M, Sheedy K. Vaccine attitudes, concerns, and information sources reported by parents of young children: results from the 2009 HealthStyles survey. Pediatrics. 2011;127(suppl 1):S92–S99. doi:. doi:10.1542/peds.2010-1722N [CrossRef]
- Omer SB, Enger KS, Moulton LH, Halsey NA, Stokley S, Salmon DA. Geographic clustering of nonmedical exemptions to school immunization requirements and associations with geographic clustering of pertussis. Am J Epidemiol. 2008;168(12):1389–1396. doi:. doi:10.1093/aje/kwn263 [CrossRef]
- Omer SB, Salmon DA, Orenstein WA, deHart MP, Halsey N. Vaccine refusal, mandatory immunization, and the risks of vaccine-preventable diseases. N Engl J Med. 2009;360(19):1981–1988. doi:. doi:10.1056/NEJMsa0806477 [CrossRef]
- Committee on Practice and Ambulatory Medicine; Committee on Infectious Diseases; Committee on State Government Affairs; Council on School Health; Section on Administration and Practice Management. Medical versus nonmedical immunization exemptions for child care and school attendance. Pediatrics. 2016;138(3):e20162145. doi:. doi:10.1542/peds.2016-2145 [CrossRef]
- Centers for Disease Control and Prevention. The journey of your child's vaccine. https://www.cdc.gov/vaccines/parents/infographics/journey-of-child-vaccine.html. Accessed August 9, 2018.
- Plotkin SA, Orenstein W, Offit PA. Vaccines. 6th ed. Philadelphia, PASaunders; 2014.
- US Food and Drug Administration. Vaccine product approval process. https://www.fda.gov/BiologicsBloodVaccines/DevelopmentApprovalProcess/BiologicsLicenseApplicationsBLAProcess/ucm133096.htm. Accessed August 9, 2018.
- The College of Physicians of Philadelphia. Vaccine development, testing, and regulation. https://www.historyofvaccines.org/content/articles/vaccine-development-testing-and-regulation. Accessed August 9, 2018.
- Centers for Disease Control and Prevention. Vaccine safety datalink (VSD). https://www.cdc.gov/vaccinesafety/ensuringsafety/monitoring/vsd/index.html. Accessed August 9, 2018.
- Kempe A, Daley MF, McCauley MM, et al. Prevalence of parental concerns about childhood vaccines: the experience of primary care physicians. Am J Prevent Med. 2011;40(5):548–555. doi:. doi:10.1016/j.amepre.2010.12.025 [CrossRef]
- Taylor JA, Darden PM, Slora E, Hasemeier CM, Asmussen L, Wasserman R. The influence of provider behavior, parental characteristics, and a public policy initiative on the immunization status of children followed by private pediatricians: a study from Pediatric Research in Office Settings. Pediatrics. 1997;99(2):209–215.
- Bernstein HH, Bocchini JA Jr, Committee on Infectious Disease. The need to optimize adolescent immunization. Pediatrics. 2017;139(3):e20164186. doi:. doi:10.1542/peds.2016-4186 [CrossRef]
- Dorell C, Yankey D, Strasser S. Parent-reported reasons for nonreceipt of recommended adolescent vaccinations, National Immunization Survey: teen, 2009. Clin Pediatr (Phila). 2011;50(12):1116–1124. doi:. doi:10.1177/0009922811415104 [CrossRef]
- Darden PM, Thompson DM, Roberts JR, et al. Reasons for not vaccinating adolescents: National Immunization Survey of Teens, 2008–2010. Pediatrics. 2013;131(4):645–651. doi:. doi:10.1542/peds.2012-2384 [CrossRef]
- Maglione MA, Das L, Raaen L, et al. Safety of vaccines used for routine immunization of U.S. children: a systematic review. Pediatrics. 2014;134(2):325–337. doi:. doi:10.1542/peds.2014-1079 [CrossRef]
- Byington CL. Vaccines: can transparency increase confidence and reduce hesitancy?Pediatrics. 2014;134(2):377–379. doi:. doi:10.1542/peds.2014-1494 [CrossRef]
- Nyhan B, Reifler J, Richey S, Freed GL. Effective messages in vaccine promotion: a randomized trial. Pediatrics. 2014;133(4):e835–e842. doi:. doi:10.1542/peds.2013-2365 [CrossRef]
- Opel DJ, Heritage J, Taylor JA, et al. The architecture of provider-parent vaccine discussions at health supervision visits. Pediatrics. 2013;132(6):1037–1046. doi:. doi:10.1542/peds.2013-2037 [CrossRef]
- Sturm L, Donahue K, Kasting M, Kulkarni A, Brewer NT, Zimet GD. Pediatrician-parent conversations about human papillomavirus vaccination: an analysis of audio recordings. J Adolesc Health. 2017;61(2):246–251. doi:. doi:10.1016/j.jadohealth.2017.02.006 [CrossRef]
- Hofstetter AM, Robinson JD, Lepere K, Cunningham M, Etsekson N, Opel DJ. Clinician-parent discussions about influenza vaccination of children and their association with vaccine acceptance. Vaccine. 2017;35(20):2709–2715. doi:. doi:10.1016/j.vaccine.2017.03.077 [CrossRef]
- Mergler M, Omer S, Pan W, et al. Are recent medical graduates more skeptical of vaccines?Vaccines (Basel). 2013;1(2):154–166. doi:. doi:10.3390/vaccines1020154 [CrossRef]
- Sadaf A, Richards JL, Glanz J, Salmon DA, Omer SB. A systematic review of interventions for reducing parental vaccine refusal and vaccine hesitancy. Vaccine. 2013;31(40):4293–4304. doi:. doi:10.1016/j.vaccine.2013.07.013 [CrossRef]
Comparison of Annual Cases of Vaccine-Preventable Diseases Before and After Vaccine Introduction
||Estimated Annual Average Cases (Pre-Vaccine Introduction)
||Number of Cases Reported in 2015
|Congenital rubella syndrome