Dermatology Online Journal

Herpes zoster vaccine awareness among people ≥ 50 years of age and its implications on immunization
Saba Javed¹ BS, Fatima Javed², Rana M Mays³ MD, Stephen K Tyring^3,4 MD PhD
Dermatology Online Journal 18 (8): 2

1. University of Texas Medical School at Houston, Houston, Texas
2. University of Houston, Houston, Texas
3. Center for Clinical Studies, Webster, Texas
4. Department of Dermatology, University of Texas Health Science Center, Houston, Texas

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Abstract

Herpes zoster (HZ) vaccine was recently approved for adults ≥ 50 years of age and has been shown to reduce the incidence of zoster, postherpetic neuralgia (PHN), and associated healthcare costs. However, currently HZ immunization is sub-optimal. We examined awareness of HZ and of the HZ vaccine. Information was gathered via a one-page survey given to patients ≥ 50 years of age presenting at the dermatology clinic. From the surveyed population of 1000 individuals, the HZ vaccination rate was 11.9 percent. Vaccination coverage was highest for the ≥ 70 age group (18.3%), followed by age groups 60-69 (8.9%) and 50-59 (1.4%). Individuals with female gender, older age (≥ 70 years), higher level of education (college and beyond), retired employment status, memory of chickenpox, knowledge of shingles, and history of shingles and influenza vaccination in the past year all were more likely to have heard of and have received the HZ vaccine (except female gender, education level, and awareness of shingles). Our study suggests lack of awareness to be a significant factor in non-immunization with zoster vaccine. Targeting adults in younger age groups and minorities would be beneficial towards increasing zoster vaccine awareness and thus preventing herpes zoster and its many complications.

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Introduction

Herpes zoster is one of the most debilitating conditions in the elderly. However, it can affect individuals of all age groups, including children. Herpes zoster (HZ, commonly known as shingles) results from the reactivation of the varicella zoster virus (VZV), which migrates to the dorsal root ganglia after infection with primary varicella zoster virus (chickenpox) and can remain latent for decades. The VZV reactivation is primarily related to an age-related decline in cell-mediated immunity. Individuals with a history of primary varicella infection have a 10-20 percent lifetime chance of developing HZ [1, 2]. Complications of HZ include but are not limited to significant pain, herpes ophthalmicus, post herpetic neuralgia (PHN), bacterial superinfection, hypopigmentation, and hyperpigmentation [1, 2, 3]. In immunocompromised individuals such as the elderly and patients with HIV, malignancy, and/or organ transplants, HZ can cause more invasive disease and potentially death [1, 2, 3]. Herpes zoster vaccine is a live attenuated virus vaccine indicated for prevention of herpes zoster. Zoster vaccine has been shown in multiple clinical studies to decrease the incidence of HZ, PHN, and associated healthcare costs. The safety and efficacy of the vaccine were evaluated in the Shingles Prevention Study in 38,546 adults aged at least 60 years [4, 5]. Compared with placebo, administration of the vaccine resulted in a 51.3 percent reduction in the incidence of herpes zoster and a 66.5 percent reduction in the incidence of PHN (P < 0.001 for both comparisons). The United States Food and Drug Administration (FDA) initially approved the vaccine in 2006 for individuals ≥ 60 years of age after the vaccine was rendered safe and efficacious by clinical trials. Recently the FDA expanded its indication to individuals of ages 50-59 [6, 7]. However, despite the benefits, HZ vaccine immunization rate in adults ≥ 60 years is a mere 6.7 percent [8]. Thus, many to this date have not been vaccinated and thus are at greater risk for HZ and its associated complications in the future.

In this survey study, we sought out to examine awareness of HZ and HZ vaccine and subsequently determine the potential reasons for sub-optimal vaccination in the general public.

Methods

Information was gathered via a one-page survey given to all patients ≥ 50 years of age presenting at the Dermatologic Association of Texas in Houston, a dermatology clinic in Texas, from July 2011 to September 2011. We collected demographic data on gender, age group (50-59, 60-69, and ≥ 70 years), ethnicity (Caucasian, Hispanic, Black, and other), marital status (never married, married, widowed, and divorced), and highest level of education (grade school, middle school, high school, college and post-graduate). Other questions on the survey included the following.

• “Do you have health insurance?”
• “Do you have a primary care physician?”
• “Have you been to your primary care doctor in the past 12 months?”
• “Do you remember having had chickenpox?”
• “Have you heard of shingles (Herpes Zoster)?”
• “Have you ever had shingles? And if yes, when?”
• “Do you have any family members (blood relative) who had shingles?”
• “Do you have friends and/or a spouse who had shingles?”
• “Have you received the influenza vaccine in the past year?”
• “Any adverse reaction to vaccines in the past?”
• “Have you heard of HZ vaccine, the vaccine for prevention of shingles?”

Those who responded negatively to the last question (“Have you heard of HZ vaccine, the vaccine for prevention of shingles?”) were asked to stop answering any further questions. Those who responded positively to that question were asked to continue answering the following questions.

• “How did you first hear about HZ vaccine?”
• “Have you already received HZ vaccine? And if yes, when?”
• “Did you know it was recently approved by the FDA for people 50 of older?”

Those who had received the vaccine were asked “How did you pay for the vaccine?” Whereas those who had not received the vaccine were asked to answer the following questions.

• “Don’t believe you are at risk?”
• “Concerned about the cost?”
• “Concerned about the side-effects?”
• “Suffer from a medical condition?”
• “Difficulty obtaining the vaccine?”
• “Other?”

The continuous variables were reported as mean (standard deviation, SD) and were analyzed using the unpaired 2-tailed t-test. The discrete variables were analyzed using the χ² test. For each variable, including sex, age, race, and others, we computed the odds ratios (ORs) and corresponding 95 percent confidence intervals (CIs). Statistical analyses were performed using Epi-Info™ Version 3.5.1.

Results

A total of 1000 adults ≥ 50 years of age were surveyed: 50.5 percent males and 49.5 percent females. The age group distribution was as follows: 50-59 years (24.4%), 60-69 years (23.0%), and ≥ 70 years (52.6%). Caucasians comprised the largest ethnicity (91.4%), followed by Hispanics (4.8%), Blacks (2.7%), and other (Asian or Native American, 1%). The marital status of the surveyed population was as follows: never married (4.5%), married (71.5%), widowed (14.4%), and divorced (9.6%). Level of education was distributed as follows: grade school (1.0%), middle school (3.4%), high school (34.7%), college (45.0%), and post-graduate (15.8%). A majority of the adults were retired (54.6%) but some were currently employed (32.6%). A large majority had health insurance (98.3%) and a primary care physician (90.4%). Results from the questionnaire are as follows: 91.8 percent visited a primary care doctor in the past 12 months, 80.8 percent remembered having had chickenpox, 88.0 percent had heard of shingles, 22.7 percent had a history of shingles (average age of onset = 66.5 [±40.9]), 31.3 percent had family members (blood relatives) who had shingles, 37.1 percent had friends and/or a spouse who had shingles, 54.6 percent received the influenza vaccine in the past year, 7.6 percent had an adverse reaction to vaccines in the past, and 41.9 percent had heard of HZ vaccine. The vaccination rate was 11.9 percent: 18.3 percent in the ≥ 70 year age group, 8.9 percent in the 60-69 year age group, and 1.4 percent in the 50-59 year age group. Of those with a positive history of shingles, 51.5 percent were women and 48.5 percent were men. Furthermore, women were more likely to report adverse events to vaccine (59.1%, P = 0.02). In addition, 92.5 percent of the Caucasians, 71.4 percent of the Hispanics, 100 percent of the Blacks, and 100 percent other noted going to the primary care physician in the past 12 months. Of the individuals with a positive history of shingles, 87.9 percent recalled having had chickenpox.

Of the 419 patients who had heard of HZ vaccine, the majority were informed via the news (34.1%), followed by a primary care doctor (28.5%), other (17.1%), dermatologist (16.3%), and pharmacy (4.1%). The vaccination rate in this subgroup (who had heard of HZ vaccine) was 28.7 percent: 36.7 percent in the ≥ 70 year age group, 21.4 percent in the 60-69 year age group, and 6.7 percent in the 50-59 year age group. Approximately 36.1 percent of adults knew the vaccine was recently approved by the FDA for people ≥ 50 years of age, 68.2 percent of whom were ≥ 70 years of age, 20.5 percent of whom were in the 60-69 age group, and 11.4 percent of whom were in the 50-59 age group. Of those who had received the vaccine (n = 119), the mode of payment was as follows: health insurance (73.0%), self-pay (10.8%), and enrolled in study (16.2%).

Table 1 and Table 2 describe the demographic and clinical characteristics of individuals who were aware of HZ vaccine and received the vaccine. Table 3 lists the reasons for not receiving the vaccine.

Discussion

Herpes zoster vaccine has been shown in multiple clinical studies to reduce the incidence of HZ, PHN, and associated healthcare costs [4, 5]. Recently, the FDA expanded the indications to include adults in the age group of 50-59 [7]. In our study, immunization with HZ vaccine in adults ≥ 50 years of age was 11.9 percent, which is slightly higher than the CDC reported national value of 6.7 percent, but still considerably lower than other preventative vaccines [8]. The administration of influenza vaccine, for instance, in adults (≥ 65 years of age) has exceeded 60 percent each year for the past decade [9]. There are disparities concerning HZ vaccine, which must be identified and addressed in order to improve the vaccination rates.

From our surveyed population, 41.9 percent of individuals had heard of HZ vaccine, of which 26.1 percent were aware of its recent approval for adults ≥ 50 years of age. Lack of awareness certainly seems to play a role in the low vaccination rate. Furthermore, individuals who actually received the vaccine were approximately 7 times more likely to be informed of the recent FDA approval of HZ vaccine for adults ≥ 50 years of age than those who did not receive the vaccine (P < 0.01). Moreover, individuals 50-59 years of age were least likely to have heard of this recent FDA approval as compared to the other age groups.

Overall, our findings indicate that age was a significant factor in the awareness of HZ vaccine. Retired adults ≥ 70 years of age were more likely to have heard of HZ vaccine (P < 0.001) and more likely to have received the vaccine (P < 0.001). As far as racial disparity is concerned, Hispanics were the least likely group to be aware of HZ vaccine (P = 0.04), perhaps related to a language barrier or lower rate of primary care physician visits in the past year.

Individuals with a college or post-graduate education were more likely to have heard of HZ vaccine than those with fewer years of schooling (P < 0.001). However, their increased likelihood of getting vaccinated was not statistically significant. Moreover, none of the more-schooled (college and beyond) and 25 percent of the less-schooled individuals (high school or less) who did not recall having had chickenpox received the HZ vaccine, suggesting awareness of the fact that chickenpox and shingles are caused by the same virus in the former group. However, it is interesting to note in this study that of the total zoster cases reported, 87.9 percent recalled having had a history of chickenpox. Moreover, approximately 29.2 percent of more-educated individuals with a positive history of zoster received the vaccine, as compared to 43.3 percent of less-educated individuals, possibly suggesting that the former group is more aware of the acquired boosted immunity after the first episode of zoster. In our study, of individuals who reported having had zoster, the average age was calculated to be 66.5 years. Yawn et al. recently reported the HZ recurrence to be as high as 6.2 percent [10]. Although no definite studies to date exist showing benefit of vaccination in recurrent zoster, immunization could still prove beneficial in this particular group, but may not be cost effective.

Individuals with a memory of chickenpox had a significantly higher rate of HZ vaccination, compared to individuals with no history or memory of the disease (P = 0.018). This indicates that patients are more likely to be aware of the disease and its potential prevention if they had a past diagnosis of varicella. Furthermore, in our study, individuals who had received the influenza vaccine were more likely to also have had knowledge of HZ vaccine (64.8%, P = 0.0014), and were therefore more likely to have received the HZ vaccine (P = 0.002). This could be explained by patients being more proactive in preventive care and immunization related to personally witnessing benefits of other vaccines such as the influenza vaccine.

With the incidence of herpes zoster increasing drastically in the past 30 years, immunization is key to prevention of disease, further morbidity, and mortality [11]. There are many sources of preventative health education available to the general public, including the primary care physician, dermatologist, news or media, pharmacist, and others (friends, relatives, colleagues). Of the patients who received HZ vaccine, a majority were informed via their primary care physician, with the media following as a second mode. Of the individuals who were informed but did not receive the vaccine, the perception of not being at risk was the number one cause, followed by concern about cost, and adverse events. Health insurance covered the cost for a large percentage of individuals ≥ 60 years of age but none in the age group of 50-59 years, because the vaccine is not yet covered by health insurance for this age group. Thus, cost could be the decisive factor for all age groups but particularly for those 50-59 years of age.

A limitation to this study is that the responses were self-reported, including the HZ vaccination. No studies have evaluated the validity of self-reported HZ vaccination. However, previous studies have noted that self-reported influenza vaccination was reliable with review of medical records [12]. Also, individuals surveyed were those who presented at a private dermatology clinic. Thus these adults may not be a valid representation of individuals of the general population. Furthermore, numbers for those who have heard of HZ vaccine and who have received HZ vaccine might be inflated in our study because dermatologists often educate their patients on this preventive vaccine.

Conclusion

Our study suggests lack of awareness to be a significant factor is non-immunization with HZ vaccine. Our sub-analysis of patients who were informed but still did not receive HZ vaccine indicates that mere information about the existence of vaccine is not adequate. Patients must fully be educated on the vaccine, the age groups at risk, potential options for payment, adverse events, and potential risks and benefits. With better awareness and proper education about HZ vaccine, we can potentially improve immunization and further reduce incidence of zoster and its associated complications. Moreover we have illustrated the necessity for enhancement of the clinician’s role in zoster education and prevention. Patients who present to their primary care physician or dermatologist for annual skin examination and/or or focused skin problem, could also be informed of the HZ vaccine, its indications and its associated risks and benefits as another means to increase the awareness.

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