Vaccines Are Profoundly Effective, and We Can’t Stop There

In 1999, the Centers for Disease Control and Prevention hailed vaccines as one of the 10 great public health achievements of the 20^th century. Over the last few decades, scientific advances have resulted in the availability of vaccines for once-fatal illnesses, and public health investments in vaccine provision have resulted in high coverage for most routine childhood vaccines.¹ 

In this issue of Pediatrics, Talbird et al report estimates of vaccine-preventable disease incidence for vaccines routinely administered to children in the United States.²  The authors analyzed various historical records and contemporary public health data systems and found greater than a 90% reduction in incidence of 10 illnesses after the introduction of vaccines: diphtheria, Haemophilus influenzae type b, measles, mumps, pertussis, polio, rotavirus, rubella, tetanus, and varicella. An estimated 24 million cases of vaccine-preventable diseases were averted on the basis of 2019 United States population estimates, with the greatest reductions seen in influenza, measles, mumps, rubella, pertussis, varicella, and acute otitis media caused by Streptococcus pneumonia.

The marked reduction in vaccine-preventable disease translates to significant benefits to society. Using the 2017 United States birth cohort, Carrico et al, in a second related article in this issue of Pediatrics, created an economic model on the basis of the morbidity and mortality prevented by vaccination to estimate the incurred and averted costs resulting from vaccination.³  The analysis estimated that, over the lifetime of the cohort, childhood vaccines prevented 31 000 deaths and added 853 000 life-years while resulting in a net societal cost-savings of $55.1 billion (a 7:1 benefit-to-cost ratio).

Despite these profound benefits, the past successes of vaccination efforts in the United States are not guaranteed to persist into the future. Talbird et al noted, “With sustained vaccine coverage at levels >80% for most pediatric vaccines…many vaccine-preventable diseases are now controlled as a public health problem or eliminated in the United States.” The authors go on, however, to note the fragility of this accomplishment, citing undervaccination resulting in outbreaks of measles in the United States and diphtheria in other parts of the world.² 

The National Immunization Survey–Child noted that, among the 2017–2018 birth cohort, 1.0% of all children in the United States had not received any vaccinations, with higher proportions among uninsured children (3.3%).⁴  Among school-aged children, the percentage of children who had received all required vaccines in the 2020–2021 school year fell by approximately 1 percentage point to 94% (representing a decrease of ∼31 000 children), compared with 2019 to 2020.⁵  The percentage of kindergartners with an exemption for one or more school vaccines has increased from 1.6% (2011–2012) to 2.2% (2020–2021), with most of the increase because of nonmedical (versus medical) exemptions.⁶ 

Although the Centers for Disease Control and Prevention cited vaccines as a top public health achievement in the last century, the World Health Organization has now listed vaccine hesitancy as 1 f the top 10 threats to global health.⁷  The impact of medical misinformation on vaccine hesitancy has most recently been seen during the rollout of coronavirus disease 2019 (COVID-19) vaccines.⁸  However, pediatricians have been aware of, and fighting against, misinformation for >2 decades. The fallout from a retracted study falsely claiming a link between autism and the vaccine against measles, mumps, and rubella resulted in decreases in immunization rates and measles outbreaks in multiple states.^9,10  As noted in the 2021 Surgeon General’s Advisory on Confronting Health Misinformation, pediatricians play an important role as trusted messengers for parents and can help dispel vaccine misinformation.⁹ 

The COVID-19 pandemic further exacerbated efforts to administer routine pediatric immunizations. After the initiation of stay-at-home orders in early 2020, fewer children received well-child visits and routine immunizations.^11–13  The catch-up in immunizations that occurred later in 2020 was insufficient to fully address the deficit left from earlier waves of the pandemic.¹⁴  Aggressive efforts, such as those that seek to reconnect children to medical homes and align key community partners to promote preventive care for children, are essential to getting children caught up and keeping them healthy.

The pandemic also brought to the forefront many of the inequities experienced by communities of color across our public health and health care systems. As a result of data limitations, neither of the analyses cited in these 2 articles reports differences among racial or ethnic groups with regard to vaccination coverage, disease incidence, or reductions in morbidity and mortality. Yet, vaccine disparities exist. Among 24-month-olds, vaccine coverage rates for the combined 7 vaccine series (diphtheria, tetanus, and acellular pertussis; poliovirus; measles; Haemophilus influenzae type b; hepatitis B; varicella; and pneumococcal), as well as influenza and rotavirus, are lower for non-Hispanic Black and Hispanic toddlers compared with their White counterparts.⁴  Inequities in vaccine coverage may translate to variations in disease incidence, creating differential disease burdens and differences in accrued benefits among racial and ethnic groups.¹⁵ 

Persistent contemporary and historical medical injustices, such as the Tuskegee experiments, may contribute to continued distrust and vaccine hesitancy among some populations.¹⁶  Additionally, many populations of color experience lower rates of health insurance and higher rates of barriers to health care, including social determinants of health, that might affect vaccination rates.¹⁷  With these challenges in mind, population-level efforts to improve vaccination coverage must deliberately address social and structural determinants of health.

Moving forward, we should strive to maintain high immunization rates at the population level and assure equity across populations. Health care systems and public health entities must specifically measure health care utilization and outcomes across and within racial and ethnic groups, and work with clinical providers and other partners to close the gap on any inequities. Pediatricians should engage families, understand their concerns, and address hesitancy and distrust in culturally and linguistically congruent dialogue. Pediatricians can leverage community health workers or community leaders as trusted messengers on the importance and safety of vaccines for children.¹⁸  Pediatric practices and children’s hospitals can support the formation of patient and family advisory councils; these groups can provide valuable insights for clinicians and administrators on the delivery of care and how best to address concerns and unique needs of specific populations.¹⁹  Clinics and hospitals can also enlist other community organizations to help address social determinants of health, including through medical–legal partnerships.²⁰ 

The studies authored by Carrico et al³  and Talbird et al²  in this issue of Pediatrics provide strong confirmation of what pediatricians know well: vaccines prevent illness, vaccines save lives, and vaccines are beneficial to society. However, the impact of misinformation on vaccine hesitancy, pervasive inequities among marginalized communities, and the disruption of the COVID-19 pandemic on routine preventive care for children underscore the need for pediatricians to be actively involved in assuring a strong system for vaccine delivery and uptake. Pediatricians in partnership with the health care system and public health must actively support robust data and delivery systems that assure the equitable provision and uptake of vaccines across populations. A concerted effort across all parts of the health care and public health systems can assure that vaccines remain one of the greatest public health achievements of our time.

COVID-19

coronavirus disease 2019