This article for developing awareness surrounding racial and ethnic disparities in care was funded by GSK.
Dr Jose Camargo is contracted by GSK and is compensated for the development of this article.

Adult vaccine-preventable diseases are reviewed as vaccination rates lag behind public health preventative care benchmarks across many common diseases. Barriers to receiving vaccinations are discussed, and strategies to improve vaccine uptake are explored.

Vaccinations are crucial for protecting individuals from vaccine-preventable diseases and promoting public health and wellness. The Centers for Disease Control and Prevention recommends and tracks adult vaccination status for COVID-19, influenza, pneumococcal, tetanus toxoid-containing (tetanus and diphtheria vaccine [Td] or tetanus and diphtheria with acellular pertussis vaccine [Tdap]), hepatitis A, hepatitis B, varicella-zoster (shingles), and human papillomavirus (HPV) vaccines. Infection with any of these organisms can lead to debilitating and in some cases potentially life-threatening complications requiring specialized care and hospitalization. Therefore, it is critical to understand the benefits of vaccination and the consequences of vaccine avoidance, especially in traditionally underserved populations. With this information, we can begin to develop strategies to improve vaccine uptake and protect our patients from serious diseases.

Influenza and COVID-19 are spread via respiratory droplets (airborne transmission) and present with similar symptoms, such as fever, cough, and myalgias. While these are typically acute illnesses in the general population, they can progress and lead to severe respiratory distress and other complications, especially in the elderly and immunocompromised populations. Pneumococcal disease is also an airborne illness known to cause bacterial pneumonia; however, it can also lead to meningitis, sepsis, and infective endocarditis.

Tetanus is acquired through cuts in the skin that become infected with the bacterium Clostridium tetani. Symptoms of infection include muscle stiffness, spasms, lockjaw, and, in severe cases, seizures. Diphtheria and pertussis are also caused by respiratory-spread pathogens. For diphtheria, typical symptoms include fever, sore throat, and lymphadenopathy. It can have severe consequences, such as heart failure, if the toxin reaches the bloodstream. With pertussis, or whooping cough, there is a possibility of developing pneumonia.

Hepatitis A is acquired via the oral-fecal route, whereas hepatitis B is transmitted through blood and bodily fluids. Both can be asymptomatic but also can lead to liver inflammation. Importantly, hepatitis B can lead to chronic hepatitis infection and cirrhosis. Furthermore, it is a known risk factor for hepatocellular carcinoma.

Shingles is caused by the varicella-zoster virus (VZV) and is spread through direct contact or reactivated in nerve tracts through an age-related decline in immunity. The latter occurs in patients who have had a previous infection with VZV (typically chickenpox in childhood). As they age, natural immunity against the virus declines, and the virus manifests as a burning and deeply painful dermatomal rash. Symptoms can progress to postherpetic neuralgia, which can cause debilitating pain long after the infection is gone. If there is ocular involvement, the infection can lead to blindness.

HPV is spread through direct skin or sexual contact. Although some patients remain asymptomatic, clinical manifestations of the virus are evident when evaluating cases of anogenital warts. Exposure to HPV is a known risk factor for the development of certain anal and cervical cancers.

Given this information, I believe that routine vaccinations can have profound impact by greatly reducing unnecessary costs and burdens on the individual patient, the healthcare system, and society as a whole. It is important for healthcare providers to understand the consequences of missed vaccinations for an individual and the community at large. Recent data show adult vaccination rates lag far behind childhood vaccination rates and remain suboptimal. When comparing vaccination status amongst races, we find the White population has a higher vaccination rate than African American and Latinx populations amongst most recommended vaccinations. For example, in 2020, 33.4% of White adults (≥50 years old) received the recommended varicella-zoster vaccination, compared with only 17.4% of African American adults and 15.6% of Latinx adults.

To improve vaccination uptake in adults, we must first understand the barriers encountered by our patients. I find the most common barriers include lack of education around vaccinations, which can make patients hesitant to receive them. Vaccine hesitancy is more frequent in younger populations (ages 18-44) with lower income and education levels. Also, studies demonstrated there is some level of mistrust amongst patients and the medical community. I discuss the risks and benefits of vaccination with my patients if I discover they are hesitant or lacking information about vaccines. I find that once patients are more educated on vaccinations, they are more amenable to receiving them as a part of their routine preventative care.

Additionally, vaccines could be made more accessible to historically underserved populations. I find some clinics, especially in under-resourced neighborhoods, may not carry every vaccination I would want my patients to receive. A simple way I can address this is to issue a prescription for the vaccine along with any other prescriptions the patient may be refilling at their local pharmacy. Retail pharmacies have the resources and infrastructure to store and administer vaccinations, and this measure could improve vaccine uptake. Other variables that relate to access include insurance coverage and financial burden, which also contribute to low vaccine uptake.

The recent COVID-19 pandemic can be used to highlight the importance of widespread vaccine availability. The vaccines developed to fight COVID-19 have been shown to have a significant impact on rates of infection, hospitalization, and mortality. Thankfully, upon authorization for emergency use, these vaccines were made widely available to the public at no cost. We know that improvements in vaccination rates were associated with reductions in disease mortality and incidence, although these correlations were stronger during the first year of the pandemic than during the period of delta strain predominance. Allowing the vaccines to be available to people regardless of their ability to pay for them removed one potential barrier to vaccine uptake. This may be a lesson in our fight against other diseases as well.

Review of Vaccine-Preventable Diseases in Adults*

*Vaccination for these conditions may be administered in younger populations, such as adolescents. For complete vaccination recommendations, consult the CDC Adult and Adolescent Vaccination schedules (referenced below).