Crucial Conversations in Pharmacy Practice: Improving Patient Outcomes in Shingles Management

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Introduction

Herpes Zoster (HZ) is caused by reactivation of the varicella zoster virus (VZV) that disproportionally affects patients as they age as well as patients with compromised immune systems.^1,2 It is estimated that 1 in 3 United States (US) adults will develop shingles within their lifetime. ³ The rate of both diagnoses of HZ as well as postherpetic neuralgia (PHN) increase significantly for patients older than 50 years of age.³ Patients do not experience significant mortality related to a diagnosis of HZ, but nearly 20% of patients who get HZ experience PHN which can significantly affect an individual patient’s quality of life.³

Pharmacists have been well positioned over the past two decades to reduce the burden of HZ through advocacy, recommendation, and administration of appropriate vaccination. In addition to the increased role pharmacists have played in all types of immunizations, pharmacists and pharmacies’ ability to bill insurance for coverage of the HZ vaccine and the unique storage requirements of previous versions of the HZ vaccine drove distinctive and effective approaches to increase vaccination rates.^4,5 As the storage requirements and effectiveness data drove new versions of vaccines developed to prevent HZ, pharmacists continue to help increase initial and completion rates of the vaccine.⁶

Interprofessional Care and the Role of the Pharmacist

Multiple interprofessional approaches have shown to be effective at increasing HZ vaccination rates including thorough discharge counseling during transitions-of-care as well as providing electronic medical record (EMR) access to pharmacists.^7,8 The response to the coronavirus disease 2019 (COVID-19) pandemic in the US is a case example of how impactful empowering pharmacists to provide care can be. In response to the public health emergency, pharmacists and pharmacy technicians were provided the regulatory authority to administer pediatric and adult vaccinations (both for COVID-19 as well as others). Recent estimates confirmed that pharmacists and their teams were responsible for preventing 1 million deaths, 8 million hospitalizations, and saved $450 billion in healthcare costs because of interventions, including vaccination, during the pandemic.⁹ Despite all the progress made, there are still restrictions and differences from state to state regarding pharmacist and technician immunization authority; however, all 50 states allow the pharmacist to provide vaccination against HZ by either prescribing or administering the vaccine via a prescriber approved protocol or non-patient specific order.¹⁰ Pharmacists have a significant role to play in helping engage patients in decision-making in healthcare professional-patient dialogue around recommendations related to HZ regardless of their pharmacy technician’s authority to administer HZ vaccines.

Case 1

LB is a 63-year-old man who presents to his community-based pharmacy curious about his personal risk with diabetes and his chances of getting shingles. He would like to pick up his medications and get any vaccines he could be eligible for prior to leaving for vacation tomorrow.

Medical History: Type II diabetes and hypertension

Medications: Lisinopril 10 mg daily; Metformin 1000 mg BID; Canagliflozin 300 mg daily

Atorvastatin 20 mg daily

Pause and Reflect: Does diabetes affect LB’s risk for shingles, and is he a candidate for vaccination?

Epidemiology and Healthcare Costs of Herpes Zoster

The estimated disease burden of HZ in the US is approximately 1 million cases a year based on the previously cited data that 1 in 3 adults will be affected in their lifetime.³ As mentioned previously, HZ incidence increases with age. Across 12 countries that measured HZ rate over the lifespan, the estimated incidence was 3.4 to 4.8 episodes per 1000 person-years and the incidence increased to 11 per 1000 person-years for patients greater than 80 years of age.¹¹ Recent studies estimated unvaccinated adults in the US older than 50 years of age have a HZ incident rate of approximately 10 episodes per 1000 person-years with neurologic to cutaneous complications ranging from 0.77% to 6.4%, similar to adults of 80 years of age.¹² However, the recurrence rate was even higher and an estimate 10-year recurrence risk was greater than 10% in unvaccinated adults.¹² These results reinforce the importance and impact of prevention of HZ through vaccination.

HZ has a high financial burden to the healthcare system—particularly if patients experience complications such as PHN. Measured over 2 decades, age-adjusted HZ episode rates were used to estimate the costs of HZ over two decades from 1997 to 2014 and the results showed an increase in per-episode drug cost and medical cost.¹³ However, a decrease in hospitalizations (possibly due to the impact of immunizations) held overall costs during that window but authors predicted a rising cost burden of HZ due to increasing incidence due to an aging US population.¹³

Management of Herpes Zoster and Complications

Treatment of HZ consists of antiviral treatment and pain control. Once a patient presents with classical dermatological presentation that results in a clinical diagnosis, patients are treated with 1 of 3 common antivirals in the US: acyclovir, famciclovir, or valacyclovir.¹⁴ Outside of the US, amenamevir (a helicase-primase inhibitor; HPI) has shown efficacy in the treatment of HZ in Japan but is currently not approved in the US.¹⁵ Patients with diagnosed HZ should be treated within 72 hours of the onset of rash for maximum efficacy.¹⁶ Patients may also receive adjunctive treatment over-the-counter (OTC) for pain associated with HZ, including acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) after they are diagnosed.

PHN is the most common serious complication from HZ and is defined as pain resulting from dermatological presentation of HZ at least 90 days after the initial appearance of a rash.¹⁷ It is estimated that this pain exists as the result of nerve damage during HZ. PHN can be an incredibly painful complication that continues for patients even up to 2 years or more after HZ infection; the incidence of PHN increases with age, increasing 2.5x for patients 50-54 to 80-84.¹⁷ Previous systematic reviews and evidence confirm efficacy in both topical and oral treatments including topical (lidocaine patch; capsaicin cream/patches) options or oral therapeutics (gabapentin, pregabalin, amitriptyline, morphine, or tramadol).^18,19

Gabapentin or pregabalin remain the initial treatment of choice for PHN followed by topical therapy and/or tricyclic antidepressants.^17,20 Difficulties in treating pain, especially over the long-term, with the currently available therapies reinforce the importance of prevention to reduce the burden of complications associated with HZ.

Case 2

TF is a 53-year-old woman who presents to your clinic-based pharmacy asking about shingles. TF presented with maculopapular lesions with localized pain and received a diagnosis of shingles from her primary care provider. She arrives with a prescription for valacyclovir 1000 mg by mouth three times daily for seven days and asks about how soon she can get the vaccine.

Medical History: Hypothyroidism and seasonal allergies

Medications: Levothyroxine 125 mcg daily, Cetirizine 10 mg daily

Pause and Reflect: Does TF’s diagnosis of shingles prevent her from being a candidate for vaccination?

Impact of Age-Related Immune Decline and Immunosuppression

Those at highest risk for HZ and severe complications such as PHN are older adults and those with compromised immune systems. A decline in the effectiveness in the immune system is a strong predictor of risk for HZ in either case. Since HZ is a reactivation of latent virus infection with VZV, and most of the population is seropositive for VZV, understanding of the decline in immunity impacts risk, treatment, and vaccination recommendations.²¹

Previous studies have confirmed the link between immunosuppression and risk for HZ. Examples of immunosuppressive diagnoses include hematopoietic stem cell transplants, solid organ transplants, malignancy, and human immunodeficiency virus infection. Risks of HZ for patients with stem cell transplants and/or malignancy were between 6 and 10 times higher than the general population.²² Risks were also elevated with other disease states that affect the immune system (or patients treated with immunosuppressive therapies) including systemic lupus erythematosus, inflammatory bowel disease, and rheumatoid arthritis.²³ While not as pronounced as immunosuppressive diseases and therapies, aging’s impact on the immune system remains the main risk factor for HZ.²⁴ This is true across multiple areas of the world—with the lifetime risk of shingles increasing to 50% at 85 years of age; shingles disproportionately affects older adults regardless of gender or exposure to VZV via infection or vaccination.^25,26

Vaccine Recommendations and Evidence

The first vaccine for VZV was introduced in the US in 1995 and was indicated for the prevention of varicella (chickenpox) in children 12 months of age or older who lacked immunity to the disease.²⁷ These recommendations remain consistent today where all children without a valid contraindication receive a 2-dose varicella vaccination series administered at 12 to 15 months and a second dose at 4 to 6 years.²⁸ The vaccine has been very effective at reducing death related to varicella as well as age-adjusted mortality rates—specifically for children 12 months to 4 years of age.²⁷

Between infection and vaccination, US population exposure to VZV remains high while the inclusion of vaccination for all children reduced mortality from VZV infection. To ensure appropriate immunologic coverage, the Advisory Committee on Immunization Practices (ACIP) specifically cites the following recommendations for all patients to ensure documented immunity to VZV must include one of the following:²⁹

• Documentation of age-appropriate varicella vaccination
  • Preschool-age children (i.e., age 12 months through 3 years): one dose
  • School-age children, adolescents, and adults: two doses
• Laboratory evidence of immunity or laboratory confirmation of disease
• Birth in the US before 1980 (should not be considered evidence of immunity for healthcare personnel, pregnant women, and immunocompromised people)
• Diagnosis or verification of a history of varicella or herpes zoster by a healthcare provider

From the above criteria, adults in the US who were born in 1979 or earlier (44 years of age or older as of 2023) are considered exposed to VZV as estimates confirm that greater than 99% of the US adult population at that age have exposure to VZV. Given the risk of HZ from VZV reactivation, vaccinations were developed for older adults specifically to prevent HZ in older adults.

Older Adults

The first vaccine approved for the prevention of HZ by the US Food and Drug Administration (FDA) was a zoster vaccine developed as a live, attenuated vaccination (Zostavax; ZVL) in May 2006 for adults 60 years of age and older.³⁰ This was a single dose vaccination administered subcutaneously (0.65 mL) that contained 14 times more VZV strain than the pediatric version of the VZV to produce the necessary immune response in older adults.³⁰ The vaccine was moderately effective and reduced the risk of getting HZ by approximately 50%.³¹ While this initial approval provided protection where none existed before, there were significant drawbacks: ZVL was contraindicated in patients who were immunocompromised because it was a live vaccine, and the original approval did not have sufficient data to recommend ZVL in adults 50 to 59 years of age.

ZVL remained the only vaccine available to older adults from 2006 until 2017 when the second vaccine was approved for the prevention of HZ by the FDA in October 2017.³² This vaccine was an adjuvant-containing recombinant vaccine (Shingrix, RZV) administered intramuscularly (0.5 mL) as part of a two-dose series administered 2 to 6 months apart. RZV was notable for how much more efficacious it was than ZVL; multiple studies confirmed significant efficacy ranging from 96-97% effective in adults 50 to 69 and 97% effective in adults greater than 70 years of age at the one-year mark.^33,34 Despite being 2 vaccinations with RZV versus 1 with ZVL, the Centers for Disease Control and Prevention (CDC) modeled that RZV would provide improved long-term efficacy based on waning effectiveness and subsequent data have shown clinical benefit up to 10 years post-vaccination.^32,35

As a result of these data, ACIP voted in favor of the following recommendations:³²

• “RZV use in immunocompetent adults aged ≥50 years
• RZV use in immunocompetent adults who previously received ZVL
• Preferential use of RZV”

All patients without a valid contraindication should receive 2 doses of RZV even if they were previously vaccinated with ZVL. As a result of ACIP’s preferential recommendation and efficacy of the current vaccine, ZVL has not been available in the US since 2020 and it can be assumed that any patient who received ZVL in the past can safely receive 2 doses of RZV if not previously vaccinated.³⁶

Compromised Immune Systems

Given the contraindication for ZVL for immunocompromised patients, RZV held the potential of a vaccination to benefit those at risk for HZ as a result of immunosuppressing diagnoses or treatments; however, the data used for FDA approval did not initially study the efficacy of RZV in this population.³² Subsequent data confirmed efficacy against HZ in this patient population, reduced risk for PHN, and no significant risks in administering RZV in this patient population comparable to placebo.³⁶ RZV specifically showed efficacy of 68.2% in patients with stem cell transplantation, and 87 to 90% in patients with other hematological malignancies.^37,38 These outcomes, combined with confirmatory studies on risk of adverse events, were supplemented with two economic outcome analyses that showed vaccination with RZV in immunosuppressed patients with autoimmune and inflammatory diseases produced the highest amount of quality-adjusted life-year when avoiding an episode of HZ.³⁶

As of October 2021, ACIP now recommends the full RZV 2-dose series to all immunosuppressed patients using the same vaccination schedule for adults 19 years of age and older.³⁶ If possible, patients should be fully vaccinated prior to known immunosuppression (such as starting an immunosuppressive agent) to produce the most robust immune response. RZV continues to be recommended to any individuals with a history of HZ (after acute infection resolves) and should be administered to any patient born after 1980 who has documented immunity to VZV described above.³⁶ Table 1 provides a summary of HZ vaccinations approved in US.

Racial and Ethnic Disparities

While age and immune system function remain the main risk factors for HZ, racial and ethnic disparities continue to impact the ability to prevent HZ in Black and Hispanic patients. Previous studies show that despite adjusting for gender, marital status, insurance, and age, white patients are significantly more likely to be vaccinated against HZ.³⁹ Even more crucially for pharmacists, the study noted that differences may be due to lack of education which pharmacists are uniquely positioned in their communities to address.

It is critical that pharmacists identify and consider strategies to address racial and ethnic disparities by recommending appropriate vaccination to all patients and taking specific measures to address disparities by focusing on the public health needs specific to their community. It is estimated that reducing disparities by vaccinating elderly Black patients would reduce over 34,500 cases of HZ and save 180 million dollars in health-care costs.⁴⁰

Case 3

BN is a 42-year-old woman who presents to her community-based pharmacy asking about the shingles vaccine. She is joined by her father, PL, a 73-year-old man, with no significant PMH. She presents with no history of self-reported shingles but was recently told she will start immunosuppressive therapy for ulcerative colitis (UC) in 3 months from an infusion center. She asks about how soon she should get the vaccine.

Medical History: Ulcerative Colitis

Medications: Mesalamine 800 mg 3 times daily; patient will begin infliximab 5 mg/kg with the first dose in 12 weeks

Pause and Reflect: Are BN and PL candidates for vaccination? If so, should BN wait until she starts her new therapy?

Conclusion

HZ is a significant disease and the most serious complications can be prevented through effective immunization. Older adults and individuals with compromised immune systems would greatly benefit from RZV—especially with updated vaccine recommendations that emphasize the need to protect adults with immunosuppressive diseases/medications from HZ. It is important that pharmacists identify and consider strategies to address racial and ethnic disparities by recommending appropriate vaccination to all patients and taking specific measures to address disparities by focusing on the public health needs specific to their community. As demonstrated during the COVID-19 pandemic, pharmacists are well positioned to increase immunization rates and reduce ethnic disparities through effective advocacy, education, and administration of HZ vaccines.

References

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