“Assessing and Improving Zoster Vaccine Uptake in a Homeless population”

Published in the Journal of Community Health (2018) by Kaplan-Weisman, L., Waltermaurer, E., & Crump, C

In this 3-year long retrospective study, researchers sought out to increase the rate of zoster immunizations among homeless adults in New York City by providing an on-site primary care clinic partnered with a local pharmacy 3 blocks away that would deliver the vaccine directly to the shelter. They also wanted to identify any barriers to vaccination among adults who have experienced homelessness. 

From February 2015-December 2017, the zoster vaccine (Zostavax – live attenuated, single dose) was offered during routine primary care visits to any eligible adult, per the CDC guidelines, residing in NYC Valley Lodge shelter, a transitional shelter for medically complex homeless adults above 50 years of age. Any patient that was interested in getting the vaccine, an electronic prescription was sent to the local pharmacy for the pharmacist to then determine insurance coverage and copayment. At the patient’s second visit, prior to getting the vaccine, the provider would discuss cost, benefits, and risks of the vaccine with the patient, who would then decide whether they wanted to get the vaccine or not. Vaccines were delivered to the shelter and administered during individual appointments on specific vaccine days called Shingles Immunization Days (5 total were held throughout the entirety of the study.) Vaccine administration, copayment cost, insurance coverage, and if relevant, why the vaccine was declined by the patient were all recorded in the electronic health record. 

Patients aged ≥ 60 years who had received primary care at the shelter and were seen at least twice by their primary care provider during the study period were included in this study. Out of the 93 subjects identified, 37 patients accepted the vaccine (39.8%). Analysis showed that those who had accepted the vaccine were mostly men (58.1%) and were patients with 3 or more major comorbidities (63%). Patients who declined the vaccine were those who had previously declined other vaccines. Vaccine acceptance among races/ethnicities were not significantly different, but interestingly the vaccine acceptance among the African Americans (51%) and Hispanics (50%) in this study were significantly higher than the vaccination rate reported by NHIS in 2015 (13.6% African American, 15% Hispanic.) At the end of the study period, a total of 38.1% of the patient population were immunized against Herpes Zoster, whether it was through the study or prior to establishing care, which is higher than the reported national average of 30.6% by the 2015 NHIS. Additionally, the rate of vaccination in this study (37.1%) among adults 60-64 years old was significantly higher than the reported rate of 21.7%. Only mild arm pain was reported by some subjects as a side effect of the vaccine. 

Among the individuals who declined the zoster vaccine, lack of insurance coverage and patient refusal of all vaccines were the primary reasons. The study reported 92% reduced odds of accepting the vaccine if the patient had previously declined another vaccine. For everyone that were insured, the vaccine copay was less than $10, but for the unsured (1.9%) the copay ranged from $30-100. For these patients, enrollment into a Patient Assistant program was offered to receive full coverage. Another reason for vaccine refusal was concern over the side effects of a live vaccine such as injection site reactions, headache, muscle pain, and fatigue. 

This study has demonstrated that if the appropriate models are in place to increase access, physically and financially, to the zoster vaccine, it has the potential to increase vaccine uptake among the homeless population. Majority of adults, who have experienced homelessness, are interested in getting vaccinated but many lack the resources or the ability to attain the care or even know that this vaccine exists. Poor insurance coverage is a significant barrier. Currently, the zoster vaccine is considered a prescription, not a vaccine. Not only do providers need to send a prescription in for the patient to be able to get the vaccine, but the vaccine is only covered if the patient has Medicare Plan Part D or has another insurance plan. If not, the price can be as high as $100 for a single dose. Reclassification of the zoster vaccine under Medicare Part B, which covers most vaccines for the elderly already, has the potential to significantly improve vaccination rates. Additionally, effective models like the one in this study that provides easy access to a primary care clinic with an adequate refrigerator to store live or non-live vaccines can raise more awareness of the zoster vaccine, increase the rate of vaccination, achieve high levels of routine immunization in general, and decrease vaccine disparity among homeless adults. 

This study has several limitations including a small sample size and lack of generalizability to other shelters and other homeless populations (sheltered vs street). Unlike many other shelters, this shelter permitted residents to either be in their room or the common area throughout the day, allowing for more available on-site appointments that people can attend. The shelter also included extensive assistance with medical appointments and medical management that can continue after patients leave the shelter. This could have a significant impact on making that decision to seek medical care and adhere to the prescribed treatments. Further studies are warranted with a larger sample size and among different shelter environments. 

** Shingrix vaccine (FDA approved in 2017) has proven to be more effective than Zosavax in preventing shingles in adults over 50 years old. Zostavax became no longer available in the United States in November 18^th, 2020. One major difference in administration between the two drugs is that Shingrix is 2 doses (spaced 2-6 months apart), while Zosavax was a single injection. The emphasis on increasing easy access to the vaccine is stressed even more given that the patient needs to come back for a second dose or else they will be lost to follow up. https://www.cdc.gov/vaccines/vpd/shingles/public/shingrix/index.html

Source: Kaplan-Weisman, Laura et al. “Assessing and Improving Zoster Vaccine Uptake in a Homeless Population.” Journal of community health vol. 43,6 (2018): 1019-1027. doi:10.1007/s10900-018-0517-x