Assessing herpes zoster vaccine efficacy in patients with diabetes: A community-based cohort study.

The effectiveness of herpes zoster (HZ) vaccines in patients with diabetes over the age of 50 remains an active area of research. Utilizing a real-world database from the US community, this study spanning from 2006 to 2023, aimed to evaluate the impact of HZ vaccination on newly diagnosed diabetes patients who received an HZ vaccination within 1 year of diagnosis. Exclusion criteria were established to omit patients with immune deficiencies. The cohort consisted of 53 885 patients, with an average age of 63.5 years, including 43% females and 58% whites. After implementing 1:1 propensity score matching for age, sex, race, comorbidities, diabetes medication, and hemoglobin A1c to ensure comparability, the study population was further stratified into four groups: N1 comparing any HZ vaccination to non-HZ vaccination (53 882 matched pairs), N2 for Shingrix versus non-HZ vaccination (16 665 matched pairs), N3 for Zostavax versus non-HZ vaccination (12 058 matched pairs), and N4 for Shingrix versus Zostavax (11 721 matched pairs). Cox proportional hazards regression analysis revealed a hazard ratio (HR) for HZ incidence post any HZ vaccination of 0.92 (95% confidence interval [CI]: 0.83-1.01). Additional analyses yielded HRs of 1.12 (95% CI: 0.93-1.34) for Shingrix versus non-HZ vaccine, 1.02 (95% CI: 0.86-1.20) for Zostavax versus non-HZ vaccine, and 1.06 (95% CI: 0.87-1.29) for Shingrix versus Zostavax. Subgroup analyses across age, sex, and follow-up duration also showed no significant differences. These findings underscore the lack of a significant benefit from HZ vaccination in newly diagnosed diabetes patients aged over 50, highlighting the necessity for further prospective research.

Determinants of uptake of influenza, zoster and pneumococcal vaccines in patients with cardiovascular diseases.

BACKGROUND: Globally, cardiovascular disease (CVD) is the leading cause of death and illness. Vaccine-preventable infections may increase acute coronary vascular disease events and the risk of complications. Low vaccine coverage has been reported among adults at high risk of complications from vaccine-preventable infections. There is a gap in research evidence around determinants of uptake of vaccines among adults with CVD. This study examined the uptake of influenza, pneumococcal and zoster vaccines and the determinants of uptake of the vaccines among cardiac patients. METHOD: A prospective cross-sectional study was carried out among hospitalised cardiac patients through an interviewer-administered questionnaire. Descriptive statistics were used to investigate self-reported uptake of influenza, pneumococcal and zoster vaccines. Univariate and multivariate analyses of participants' social demographic and clinical characteristics were conducted to identify factors for receiving influenza vaccine. RESULTS: Low vaccination rates among 104 participants were found for influenza (45.2%), pneumococcal (13.5%) and zoster (5.8%) vaccines. The most common reason for not receiving influenza vaccine was concern about side effects. Lack of awareness about the pneumococcal and zoster vaccines was the main reason for the poor uptake of these vaccines. Australia-born participants were more likely to receive influenza vaccine than overseas-born participants. Working-age participants and, interestingly, people living with a current smoker were less likely to receive influenza vaccine. CONCLUSION: Influenza, pneumococcal and zoster vaccine uptake among cardiac patients was low. Encouraging physician recommendations for vaccination for cardiac patients under 65 years of age and addressing vaccination challenges among people from culturally and linguistically diverse backgrounds and pharmacy, workplace, and hospital vaccination may help increase vaccination uptake among cardiac patients.

Differential Utility Losses in Herpes Zoster Cases Between Vaccinated and Unvaccinated Subjects: A Meta-analysis of Three Clinical Trials.

BACKGROUND AND OBJECTIVE: Recombinant zoster vaccine (RZV) is approved in adults for the prevention of herpes zoster. The effect of RZV in moderating the severity of breakthrough cases of herpes zoster has been noted but not explicitly quantified before. In this study, a meta-analysis was undertaken to estimate differential utility losses between unvaccinated (Placebo) and vaccinated (RZV) subjects in breakthrough cases of herpes zoster from three RZV clinical trials. METHODS: Differential utility losses between the two groups were estimated in units of quality-adjusted life-years (QALYs), leveraging aggregate patient data from the ZOE-50 (NCT01165177), ZOE-70 (NCT01165229), and ZOE-HSCT (NCT01610414) clinical trials. Differential utility losses and the ratio of mean utility losses were analyzed using random-effects and fixed-effects meta-regression models. RESULTS: The mean QALY loss differences between the unvaccinated (Placebo) and vaccinated (RZV) groups were 0.008, 0.004, and 0.011 in the ZOE-50, ZOE-70, and ZOE-HSCT studies, respectively, yielding an overall estimated difference of 0.007 (95% confidence interval 0.002-0.012) QALYs. Quality-adjusted life-year loss in the vaccinated group was estimated to be 35.5% of the value in the placebo group. A sensitivity analysis estimated an overall difference of 0.005 (95% confidence interval 0.001-0.009) QALYs, corresponding to 48.6% of the QALY loss value in the placebo group. CONCLUSIONS: Recombinant zoster vaccine is effective in alleviating disease severity in breakthrough cases of herpes zoster. The results may be useful in distinguishing QALY losses between vaccinated and unvaccinated cohorts in health economics studies, particularly cost-effectiveness analyses.

Herpes zoster, also known as shingles, may cause painful rashes and persistent pain for months or even years after the initial episode. Recombinant zoster vaccine is approved for the prevention of shingles. Pivotal recombinant zoster vaccine clinical trials have reported data about the impact of shingles episodes on daily activities and overall health-related quality of life. In this work, we combined data from three recombinant zoster vaccine clinical trials and compared the loss in quality of life­measured in quality-adjusted life-years­incurred by vaccinated and unvaccinated subjects who experienced a shingles episode. We found that vaccinated patients experienced lower quality-adjusted life-year losses when they developed shingles compared with unvaccinated patients. Our results may be useful in assessing quality-adjusted life-year losses between vaccinated and unvaccinated cohorts in future herpes zoster vaccination health economics analyses.

Post-marketing surveillance of 10,392 herpes zoster vaccines doses in Australia.

BACKGROUND: Immunisation against herpes zoster is recommended for adults aged ≥ 50 years. Two vaccines, a live attenuated (ZVL, Zostavax®) and an adjuvant recombinant subunit (HZ/su, Shingrix®), are available in Australia. Immunisation guidelines are shifting their recommendations towards HZ/su because of higher efficacy in preventing herpes zoster and associated complications. However, there are limited post-marketing data comparing the safety profiles of these vaccines. METHODS: Data from SmartVax, an active surveillance system for monitoring adverse events following immunisation (AEFIs) utilised by > 450 clinics throughout Australia, were analysed. Data from patients aged ≥ 50 years, who received ZVL or HZ/su, from 1 June 2021 to 31 May 2022, at clinics that utilised SmartVax were included. The proportion of records where patients who reported any, local, and systemic AEFIs after receiving ZVL or HZ/su were compared using multivariable logistic regression models. RESULTS: Data from 10,392 immunisation records (n = 8341 ZVL; n = 2051 HZ/su) were included. The proportion of AEFIs reported was higher with HZ/su (41.9 % [any], 33.8 % [local], 25.2 % [systemic]) than with ZVL (8.7 % [any], 6.2 % [local], 3.5 % [systemic]). After controlling for demographic variables, HZ/su presented a 6-fold increase in the odds (OR 6.44; 95 %CI: 5.57-7.46) of a reported AEFI compared to ZVL. Only 59 (0.6 %) of vaccinations lead to medical attention being sought due to an AEFI. CONCLUSIONS: While rates of AEFIs was higher with HZ/su than ZVL, most AEFIs were mild and did not require medical attention. Our findings support the change in vaccine recommendations and the use of HZ/su in immunisation programs.

Immunogenicity and safety of live attenuated and recombinant/inactivated varicella zoster vaccines in people living with HIV: A systematic review.

Few papers focus their attention on VZV vaccination effectiveness among people living with HIV (PLWH). Flanking the live attenuated vaccine (VZL) available, a newly recombinant vaccine (RZV) was recently introduced and approved for HZ prevention among adults. PLWH represents a population on which a particular attention should be applied, in order to guarantee the vaccine efficacy and safety. We performed a literature search in USNLM, PubMed, PubMed Central, PMC and Cochrane Library. From all the publications found eligible, data were extracted and processed per population, vaccine type, immunogenicity and ADRs. The review of the 13 included studies shows that both RZV and VZL are immunogenic and have an acceptable safety profile in adults and children living with HIV. However, given the lack of research available about vaccine efficacy in preventing VZV and HZ in PLWH, additional studies need to be performed, in order to achieve a full completeness of data.

Herpes zoster (HZ) vaccine coverage and confidence in Italy: a Nationwide cross-sectional study, the OBVIOUS project.

BACKGROUND: Herpes Zoster is an age dependent disease and as such it represents a problem in the Italian social context, where the demographic curve is characterized by an overrepresentation of the elderly population. Vaccines against Herpes Zoster are available, safe and effective, however coverage remains sub-optimal. This study was therefore conducted to examine the variations in Herpes Zoster vaccine uptake and confidence across different regions in Italy. METHODS: This study utilized a cross-sectional computer-assisted web interview (CAWI) methodology. The survey was conducted by Dynata, an online panel provider, and involved 10,000 respondents recruited in Italy between April 11 and May 29, 2022. The sample was stratified based on geographic region, gender, and age group. Data management adhered to European Union data protection regulations, and the survey covered demographics, living conditions, and vaccination against herpes zoster (HZ), following the BeSD framework. RESULTS: The findings indicate regional disparities in herpes zoster vaccine uptake across Italy. Notably, the Islands region exhibits a particularly low vaccination rate (2.9%), highlighting the need for targeted interventions. The multivariate regression analysis showed that sociodemographic factors, limited access to healthcare services, and inadequate awareness of vaccine eligibility contribute to the lower uptake observed in this region. CONCLUSION: In conclusion, this research emphasizes regional disparities in herpes zoster (HZ) vaccination uptake in Italy. Demographic, socioeconomic, and geographic factors impact individuals' willingness to receive the vaccine. The study highlights the importance of awareness of vaccine eligibility and accessible vaccination facilities in increasing uptake rates.

Herpes zoster vaccination and the risk of dementia: A systematic review and meta-analysis.

INTRODUCTION: Previous studies have reported a decreased risk of dementia with herpes zoster vaccination. Given this background, this systematic review and meta-analysis aimed to investigate the association between herpes zoster vaccination and the risk of dementia. METHODS: We searched five databases until November 2023 for case-control, cross-sectional, or cohort studies investigating the association of herpes zoster vaccination and dementia. Odds ratios and 95% confidence intervals (95% CIs) were pooled in the meta-analysis. Meta-regression, subgroup, and sensitivity analysis were also conducted. RESULTS: We evaluated a total of five studies (one cross-sectional, one case-control, and four cohort studies) that included a total number of 103,615 patients who were vaccinated with herpes zoster vaccine. All the studies were of high quality, ranging from 7 to 9. Due to the high heterogeneity (I2 = 100%, p < .00001) observed in our study, a random effect model was used for the analysis. The pooled odds ratio was 0.84 (95% CI: 0.50, 1.43), p (overall effect) = .53), indicating that herpes zoster vaccination reduces the risk of dementia. CONCLUSION: Herpes zoster vaccination is associated with a reduction of the risk of dementia. More epidemiological studies are needed to confirm the association.

Crohn's Disease and Herpes Zoster: Being Mindful of Vaccination.

Crohn's disease is a chronic inflammatory disease of the gastrointestinal tract. Immunosuppressive therapy is the main treatment modality in Crohn's disease. Herpes zoster (HZ), caused by Varicella-zoster virus, is a relatively common albeit burdensome clinical picture mainly affecting adult population with immunosuppressive status. In this paper, we aimed to report a Crohn's disease patient with HZ to raise awareness on vaccination. There are commercially available vaccines that are shown to be safe and effective against HZ reactivation. Crohn's disease patients should be evaluated and informed about preventive options against HZ to prevent unwanted HZ-related complications.

Risk of Herpes Zoster Ophthalmicus Recurrence After Recombinant Zoster Vaccination.

Importance: The recombinant zoster vaccine (RZV) is currently recommended for immunocompetent adults aged 50 years or older and immunocompromised adults aged 19 years or older and is effective in preventing herpes zoster ophthalmicus (HZO). However, questions about the safety of RZV in patients with a history of HZO remain. Objective: To evaluate whether there is an increased risk of HZO recurrence after RZV in patients with a history of HZO. Design, Setting, and Participants: This retrospective cohort study used medical and outpatient pharmacy claims data for commercial and Medicare Advantage enrollees from the Optum Labs Data Warehouse. Patients with incident HZO from January 1, 2010, to December 31, 2021, were identified; the study period ended on March 31, 2022. The vaccinated group consisted of patients with at least 1 dose of RZV more than 90 days following the initial HZO diagnosis. The unvaccinated group consisted of patients without any record of RZV in the study period. Vaccinated and unvaccinated patients were matched using exact k:1 matching without replacement. Exposure: Recombinant zoster vaccination. Main Outcomes and Measures: The main outcome was the number of HZO recurrences with and without RZV exposure. Results: A total of 16 408 patients were included in the matched analysis, of whom 12 762 were unvaccinated (7806 [61.2%] female; mean [SD] age at diagnosis, 68.8 [10.3] years) and 3646 were vaccinated (2268 [62.2%] female; mean [SD] age at diagnosis, 67.4 [9.8] years). Within the primary risk period of 56 days after the index date (ie, the start of follow-up for the outcome), the incidence of HZO recurrence after any RZV exposure was 37.7 per 1000 person-years compared with 26.2 per 1000 person-years in the unexposed group. After controlling for race and ethnicity, inpatient stays, emergency department visits, concomitant vaccines, and eye care practitioner visits, the association between vaccination status and HZO exacerbation in the primary risk period had an adjusted hazard ratio for any RZV exposure of 1.64 (95% CI, 1.01-2.67; P = .04). Conclusions and Relevance: In this study, RZV exposure was associated with a higher likelihood of HZO recurrence in patients with a history of HZO compared with no RZV exposure. These findings support consideration that patients with a history of HZO may benefit from monitoring after receiving RZV in case of HZO recurrence.

Factors associated with shingles and pneumococcal vaccination among older Canadians.

Background: Immunization against vaccine-preventable diseases such as shingles and pneumococcal disease is especially pertinent among older Canadians. However, vaccine uptake remains low. Data and methods: Data from the Canadian Health Survey on Seniors (CHSS) - 2019/2020 were used to examine receipt of shingles and pneumococcal vaccines among Canadians aged 65 and older living in the community. Multivariable logistic regression was used to identify individual predisposing, enabling and needs-related factors associated with receipt of each type of vaccination. Reasons reported for not getting vaccinated were also examined. Results: Based on the 2019/2020 CHSS, an estimated 36.3% of Canadians aged 65 and older (2.3 million people) had received the shingles vaccine, while 51.1% (3.1 million) had received the pneumococcal vaccine. Being a woman, having higher socioeconomic status, having had the flu shot and having a regular health care provider were associated with increased odds of vaccination. Being an immigrant, living outside large population centres, and belonging to South Asian or Chinese population groups were associated with lower odds of vaccination. Over one-third of unvaccinated people did not think the shingles vaccine (39.7%) or the pneumococcal vaccine (36.6%) was necessary. Other frequently reported reasons for non-vaccination were not having heard of the vaccine or the doctor not mentioning it; for the shingles vaccine, 12% cited cost as a reason. Interpretation: Understanding factors associated with uptake of vaccines and reasons for not obtaining them among older Canadians will help to inform policy and programs aimed at preventing the burden of these diseases.

Varicella Zoster vaccination in hemodialysis patients: The state of the art.

Varicella Zoster Virus (VZV) infection is a common childhood exanthematous disease, which in adults and immunocompromised people may result in severe neurologic complications. Up to one-third of infected subjects may have VZV clinical reactivation particularly if immunocompromised. Patients affected by end-stage renal disease on hemodialysis present immunodepression that contributes to their higher incidence of VZV infections and reactivation. While antiviral treatment in these patients shows low efficacy, the prevention of VZV through vaccination avoids the primary infection and the risk of reactivation. Two VZV vaccines are currently available: the live attenuate Zoster Vaccine (LZV) and a Recombinant Zoster Vaccine (RZV), with the latter appearing to provide greater efficacy. Given the higher incidence of VZV infection and reactivation, the lesser response to antivirals and the lower impact of VZ vaccine in hemodialysis patients in terms of side effects, a higher diffusion of VZV vaccination should be promoted by nephrologists in these patients in particular in those with future transplant opportunities.

ATAGI Targeted Review 2022: Vaccination for prevention of herpes zoster in Australia.

Abstract: In November 2016, herpes zoster (HZ) vaccination for older adults, using the live-attenuated zoster vaccine (Zostavax; ZVL) was added to the Australian National Immunisation Program (NIP) with the aim of reducing morbidity from HZ and its complications, particularly for people at increased risk. Prior to the program, there were on average 5.6 cases of HZ per 1,000 persons annually in Australia, with highest risk of disease in older and in immunocompromised people. The burden of complications of HZ, such as post-herpetic neuralgia (PHN), was also highest in older and immunocompromised groups. No formal comprehensive program evaluation has been undertaken since program commencement. This review examined published literature and available vaccine administration data to summarise the evidence and considerations underpinning current use of HZ vaccines and potential future program directions in Australia. There have been modest reductions in the incidence of HZ and its complications since program introduction. However, five years into the program, challenges remain, including suboptimal vaccine coverage and significant safety concerns arising from inadvertent use of ZVL in immunocompromised people, who are contraindicated to receive this vaccine. This reduces opportunities to offset the burden of HZ-related disease. The recombinant subunit zoster vaccine (Shingrix; RZV), first registered in Australia in 2018, became available on the Australian market in June 2021. This vaccine has higher efficacy than ZVL and, as a non-live vaccine, can be used in both immunocompetent and immunocompromised people. RZV has potential to address the unmet needs of at-risk population groups. However, it has not yet demonstrated cost-effectiveness for inclusion as a funded vaccine under the NIP. The Australian HZ vaccination program has had limited effectiveness in meeting its aim in highest risk groups. Future options and challenges anticipated in using vaccination to reduce the burden of HZ and its complications are discussed in this review.

A randomized trial assessing the efficacy, immunogenicity, and safety of vaccination with live attenuated varicella zoster virus-containing vaccines: ten-year follow-up in Russian children.

In Russia, a universal varicella vaccination (UVV) program has not been implemented, and varicella vaccination coverage is low. We assessed the efficacy, antibody persistence, and safety of one- and two-dose varicella vaccination schedules in Russian children with a ten-year follow-up period, as part of an international phase IIIB, observer-blind, randomized, controlled trial (NCT00226499). Children aged 12-22 months were randomized (3:3:1) to receive two doses of tetravalent measles-mumps-rubella-varicella vaccine (V2 group), one dose trivalent measles-mumps-rubella (MMR) vaccine and one dose of varicella vaccine (V1 group), or two doses of MMR vaccine (V0 [control] group), 42 days apart. Main study outcomes were: vaccine efficacy (VE) against confirmed varicella cases, anti-varicella zoster virus (VZV) seropositivity rates and geometric mean concentrations, and reporting of (serious) adverse events ([S]AEs). The total vaccinated cohort in Russia comprised 1000 children; 900 were followed up until study end (year [Y] 10). VE estimates against confirmed varicella (Y10) were 92.4% in the V2 group and 74.7% in the V1 group. Anti-VZV seropositivity rates remained ≥99.4% in the V2 group and ≥89.7% in the V1 group from day 42 post-vaccination 2 until Y10. Occurrence of (un)solicited AEs and SAEs was similar across groups and confirmed the safety profile of the vaccines. No vaccination-related SAEs or deaths were reported. These results are consistent with the global trial results, i.e., the highest VE estimates observed following the two-dose schedule compared to the one-dose schedule. These data may inform decision-making related to potential implementation of a UVV program.

What is the context?Varicella is a common childhood disease caused by the highly contagious varicella zoster virus.Varicella vaccines have been used for more than three decades.A large clinical trial conducted in ten countries assessed the efficacy and safety of one dose of monovalent varicella vaccine or two doses of combined varicella vaccine (MMRV). The enrolled children were also followed up for a ten-year period to evaluate the persistence of the immune response and the long-term efficacy of the vaccine.What is new?Here, we present the long-term efficacy, immunogenicity, and safety results in the cohort of children enrolled in Russia, as part of the global ten-year follow-up study. We found that:The monovalent and combined vaccines reduced the number of varicella cases.The MMRV two-dose regimen displayed higher efficacy in preventing varicella of all severities compared to the one-dose regimen.The immune response conferred by the vaccine persisted up to ten years post-vaccination.No vaccination-related deaths occurred, and no safety concerns were raised.What is the impact?Vaccination against varicella resulted in long-term protective efficacy and antibody persistence over ten years post-vaccination in Russian children.Although one-dose varicella vaccination was effective at protecting against varicella, a two-dose schedule provided a more complete protection. This could inform health policy decisions regarding the implementation of varicella vaccination in routine immunization program in Russia.

Influenza Vaccine Uptake in the Year After Concurrent vs Separate Influenza and Zoster Immunization.

Importance: Fewer than half of US adults receive the influenza vaccine each year; many cite concerns about side effects, which occur infrequently. By contrast, the recombinant zoster vaccine causes systemic side effects in a large proportion of patients. Objective: To determine whether concurrent administration of the influenza and zoster vaccines was associated with a reduced likelihood of influenza vaccination in the subsequent year. Design, Setting, and Participants: This cohort study included patients aged 50 years or older who received the influenza vaccine between August 1, 2018, and March 31, 2019, and received the zoster vaccine on the same day or separately (within the prior 180 days). Data were gathered from a national claims database of patients with commercial insurance and Medicare Advantage plans. Logistic regression analysis was used to adjust for baseline demographic characteristics, comorbidities, influenza vaccine month and location (pharmacy vs medical office), and health care use (including influenza vaccination in the prior year). Exposures: Concurrent vs separate influenza and zoster vaccine administration. Main Outcomes and Measures: Receipt of the influenza vaccine in the subsequent year (August 1, 2019, to March 31, 2020). Results: Among 89 237 individuals included in this study, the median age was 72 years (IQR, 67-77 years), 58.3% were women, 70.1% were White, and 85.7% had at least 1 comorbidity. Influenza vaccine uptake in 2019-2020 was lower among 27 161 individuals who received concurrent influenza and zoster vaccines compared with the 62 076 individuals who received the vaccines on separate days (87.3% vs 91.3%; adjusted odds ratio, 0.74; 95% CI, 0.71-0.78; P < .001). Results were similar across subgroups. Conclusions and Relevance: Results of this cohort study suggest that concurrent administration of influenza and zoster vaccines was associated with a reduction in receipt of the influenza vaccine the following year. One possible explanation is that some patients could have misattributed systemic side effects caused by the zoster vaccine to the influenza vaccine. It may be preferable to administer these 2 vaccines separately or enhance patient counseling about expected vaccine side effects.

Herpes Zoster Vaccines.

Herpes zoster (HZ) affects approximately 1 in 3 persons in their lifetime, and the risk of HZ increases with increasing age. The most common, debilitating complication of HZ is the chronic neuropathic pain of postherpetic neuralgia (PHN). Two herpes zoster vaccines, a live-attenuated varicella-zoster virus (VZV) vaccine (zoster vaccine live [ZVL]; ZOSTAVAX [Merck]) and an adjuvanted VZV glycoprotein E (gE) subunit vaccine (recombinant zoster vaccine [RZV]; SHINGRIX [GlaxoSmithKline]) are licensed for the prevention of HZ and PHN in healthy older adults. The safety and efficacy of both vaccines has been demonstrated in clinical trials in immunocompetent adults and in selected immunocompromised persons and persons with immune-mediated diseases. Numerous real-world effectiveness studies have confirmed the safety and effectiveness of both ZVL and RZV. Recombinant zoster vaccine (RZV) is more effective for prevention of HZ than ZVL. Recombinant zoster vaccine is nonreplicating and is thus safe in immunocompromised persons. Additional zoster vaccines are in different stages of development. Wider distribution of safe and effective zoster vaccines will improve the health and well being of the rapidly growing population of older adults around the world.

Live Attenuated Varicella Vaccine: Prevention of Varicella and of Zoster.

Michiaki Takahashi developed the live attenuated varicella vaccine in 1974 . This was the first, and is still the only, herpesvirus vaccine. Early studies showed promise, but the vaccine was rigorously tested on immunosuppressed patients because of their high risk of fatal varicella; vaccination proved to be lifesaving. Subsequently, the vaccine was found to be safe and effective in healthy children. Eventually, varicella vaccine became a component of measles mumps rubella vaccine, 2 doses of which are administered in the USA to ~90% of children. The incidence of varicella has dropped dramatically in the USA since vaccine-licensure in 1995. Varicella vaccine is also associated with a decreased incidence of zoster and is protective for susceptible adults. Today, immunocompromised individuals are protected against varicella due to vaccine-induced herd immunity. Latent infection with varicella zoster virus occurs after vaccination; however, the vaccine strain is impaired for its ability to reactivate.

Healthcare workers' perceptions and experiences of communicating with people over 50 years of age about vaccination: a qualitative evidence synthesis.

BACKGROUND: Infectious diseases are a major cause of illness and death among older adults. Vaccines can prevent infectious diseases, including against seasonal influenza, pneumococcal diseases, herpes zoster and COVID-19. However, the uptake of vaccination among older adults varies across settings and groups. Communication with healthcare workers can play an important role in older people's decisions to vaccinate. To support an informed decision about vaccination, healthcare workers should be able to identify the older person's knowledge gaps, needs and concerns. They should also be able to share and discuss information about the person's disease risk and disease severity; the vaccine's effectiveness and safety; and practical information about how the person can access vaccines. Therefore, healthcare workers need good communication skills and to actively keep up-to-date with the latest evidence. An understanding of their perceptions and experiences of this communication can help us train and support healthcare workers and design good communication strategies. OBJECTIVES: To explore healthcare workers' perceptions and experiences of communicating with older adults about vaccination. SEARCH METHODS: We searched MEDLINE, CINAHL and Scopus on 21 March 2020. We also searched Epistemonikos for related reviews, searched grey literature sources, and carried out reference checking and citation searching to identify additional studies. We searched for studies in any language. SELECTION CRITERIA: We included qualitative studies and mixed-methods studies with an identifiable qualitative component. We included studies that explored the perceptions and experiences of healthcare workers and other health system staff towards communication with adults over the age of 50 years or their informal caregivers about vaccination. DATA COLLECTION AND ANALYSIS: We extracted data using a data extraction form designed for this review. We assessed methodological limitations using a list of predefined criteria. We extracted and assessed data regarding study authors' motivations for carrying out their study. We used a thematic synthesis approach to analyse and synthesise the evidence. We used the GRADE-CERQual (Confidence in the Evidence from Reviews of Qualitative research) approach to assess our confidence in each finding. We examined each review finding to identify factors that may influence intervention implementation and we developed implications for practice. MAIN RESULTS: We included 11 studies in our review. Most studies explored healthcare workers' views and experiences about vaccination of older adults more broadly but also mentioned communication issues specifically. All studies were from high-income countries. The studies focused on doctors, nurses, pharmacists and others working in hospitals, clinics, pharmacies and nursing homes. These healthcare workers discussed different types of vaccines, including influenza, pneumococcal and herpes zoster vaccines. The review was carried out before COVID-19 vaccines were available. We downgraded our confidence in several of the findings from high confidence to moderate, low or very low confidence. One reason for this was that some findings were based on only small amounts of data. Another reason was that the findings were based on studies from only a few countries, making us unsure about the relevance of these findings to other settings. Healthcare workers reported that older adults asked about vaccination to different extents, ranging from not asking about vaccines at all, to great demand for information (high confidence finding). When the topic of vaccination was discussed, healthcare workers described a lack of information, and presence of misinformation, fears and concerns about vaccines among older adults (moderate confidence). The ways in which healthcare workers discussed vaccines with older adults appeared to be linked to what they saw as the aim of vaccination communication. Healthcare workers differed among themselves in their perceptions of this aim and about their own roles and the roles of older adults in vaccine decisions. Some healthcare workers thought it was important to provide information but emphasised the right and responsibility of older adults to decide for themselves. Others used information to persuade and convince older adults to vaccinate in order to increase 'compliance' and 'improve' vaccination rates, and in some cases to gain financial benefits. Other healthcare workers tailored their approach to what they believed the older adult needed or wanted (moderate confidence). Healthcare workers believed that older adults' decisions could be influenced by several factors, including the nature of the healthcare worker-patient relationship, the healthcare worker's status, and the extent to which healthcare workers led by example (low confidence). Our review also identified factors that are likely to influence how communication between healthcare workers and older adults take place. These included issues tied to healthcare workers' views and experiences regarding the diseases in question and the vaccines; as well as their views and experiences of the organisational and practical implementation of vaccine services. AUTHORS' CONCLUSIONS: There is little research focusing specifically on healthcare workers' perceptions and experiences of communication with older adults about vaccination. The studies we identified suggest that healthcare workers differed among themselves in their perceptions about the aim of this communication and about the role of older adults in vaccine decisions. Based on these findings and the other findings in our review, we have developed a set of questions or prompts that may help health system planners or programme managers when planning or implementing strategies for vaccination communication between healthcare workers and older adults.