The Impact of Reactogenicity After the First Dose of Recombinant Zoster Vaccine on the Physical Functioning and Quality of Life of Older Adults: An Open-Label, Phase III Trial

Factors Influencing Herpes Zoster Vaccine Utilization Among Adults Aged 50 and Above Attending Primary Healthcare Center in Saudi Arabia: A Cross-Sectional Study

INTRODUCTION

Herpes zoster, or shingles, is a significant health concern for older adults caused by the varicella-zoster virus (VZV) reactivation. The availability of effective herpes zoster vaccines offers a crucial preventive measure to reduce the incidence and severity of this condition. However, the uptake of the available vaccine remains suboptimal, especially among adults aged 50 and above. Understanding the factors that influence vaccine utilization is not only essential for developing strategies to improve vaccination rates but also has the potential to significantly reduce the disease burden.

METHODS

This cross-sectional study aimed to identify factors influencing herpes zoster vaccine utilization among adults aged 50 and above attending primary healthcare center in Saudi Arabia. Data were collected using a validated questionnaire administered to visitors attending Al-Wazarat Primary Healthcare Center in Riyadh. Descriptive and inferential statistics were employed to analyze the data.

RESULTS

A total of 403 participants were included in the study, with 73.7% of participants having heard of the disease, yet only 34.2% had received the vaccine. Vaccine uptake was significantly associated with gender, educational level, and healthcare provider recommendations. Common barriers to vaccination included fear of side effects, lack of perceived susceptibility, concerns about vaccine effectiveness, and access to healthcare facilities.

CONCLUSION

Herpes zoster vaccine utilization among older adults in Saudi Arabia is relatively low despite moderate awareness. Enhancing public education through targeted campaigns and strengthening healthcare provider recommendations are crucial to improving vaccine uptake. Addressing specific barriers and misconceptions is essential to reduce the burden of herpes zoster in this population. The need for future research to explore strategies to overcome these challenges and promote higher vaccination rates is urgent and important.

Benefit-Risk Assessment of mRNA COVID-19 Vaccines in Children Aged 6 Months to 4 Years in the Omicron Era

BACKGROUND

There is no risk and benefit assessment of COVID-19 vaccination for children younger than 5 years using a single health outcomes scale. The objective of this study is to compare the expected risk and benefits of the mRNA primary series of COVID-19 vaccines for children aged 6 months to 4 years in the United States using a single health outcome scale in the Omicron era.

METHODS

The expected benefits and risks of the primary two-dose series of mRNA COVID-19 vaccines for children aged 6 months to 4 years were stratified by sex, the presence of underlying medical conditions, the presence of infection-induced immunity, and the type of mRNA vaccine (BNT162b2 or mRNA-1273). A scoping literature review was conducted to identify the indicators in the decision tree model. The benefit-risk ratio was the outcome of interest.

RESULTS

The benefit-risk ratios ranged from 200.4 in BNT162b2 for males aged 6-11 months with underlying medical conditions and without infection-induced immunity to 3.2 in mRNA-1273 for females aged 1-4 years without underlying medical conditions and with infection-induced immunity.

CONCLUSIONS

The expected benefit of receiving the primary series of mRNA vaccines outweighed the risk among children ages 6 months to 4 years regardless of sex, presence of underlying medical conditions, presence of infection-induced immunity, or type of mRNA vaccines. However, the continuous monitoring of the COVID-19 epidemiology as well as vaccine effectiveness and safety is important.

Preclinical immunogenicity of an adenovirus-vectored vaccine for herpes zoster

Herpes zoster (HZ) results from waning immunity following childhood infection with varicella zoster virus (VZV) but is preventable by vaccination with recombinant HZ vaccine or live HZ vaccine (two doses or one dose, respectively). Vaccine efficacy declines with age, live HZ vaccine is contraindicated in immunosuppressed individuals, and severe local reactogenicity of recombinant HZ vaccine is seen in up to 20% of older adults, indicating a potential need for new vaccines. Nonreplicating chimpanzee adenovirus (ChAd) vectors combine potent immunogenicity with well-established reactogenicity and safety profiles. We evaluated the cellular and humoral immunogenicity of ChAdOx1 encoding VZV envelope glycoprotein E (ChAdOx1-VZVgE) in mice using IFN-γ ELISpot, flow cytometry with intracellular cytokine staining, and ELISA. In outbred CD-1 mice, one dose of ChAdOx1-VZVgE (1 × 10⁷ infectious units) elicited higher gE-specific T cell responses than two doses of recombinant HZ vaccine (1 µg) or one dose of live HZ vaccine (1.3 × 10³ plaque-forming units). Antibody responses were higher with two doses of recombinant HZ vaccine than with two doses of ChAdOx1-VZVgE or one dose of live HZ vaccine. ChAdOx1-VZVgE boosted T cell and antibody responses following live HZ vaccine priming. The frequencies of polyfunctional CD4+ and CD8+ T cells expressing more than one cytokine (IFN-γ, TNF-α and IL-2) were higher with ChAdOx1-VZVgE than with the conventional vaccines. Results were similar in young and aged BALB/c mice. These findings support the clinical development of ChAdOx1-VZVgE for prevention of HZ in adults aged 50 years or over, including those who have already received conventional vaccines.

Recombinant zoster vaccine in immunocompetent and immunocompromised adults: A review of clinical studies

Herpes zoster (HZ) is a debilitating vaccine-preventable disease. Impairment of cell-mediated immunity, as observed with aging and immunosuppressive disorders and therapies, increases risk. Recombinant zoster vaccine (RZV) is efficacious against HZ in adults aged ≥50 years in different settings, and in immunocompromised adults aged ≥18 years who are at increased risk of developing HZ. RZV is the first and only HZ vaccine approved for use in immunocompromised adults globally, including in Europe and the US. RZV has a clinically acceptable safety profile and elicits robust immune responses in adults aged ≥50 years, and in immunocompromised adults aged ≥18 years who are at increased risk of HZ. Additionally, RZV is efficacious against HZ complications such as post-herpetic neuralgia and HZ-related pain. This review updates knowledge from a randomized controlled trial setting on the efficacy, safety, immunogenicity, and impact on quality of life of RZV.

Pre-Clinical Development of an Adenovirus Vector Based RSV and Shingles Vaccine Candidate

Respiratory syncytial virus (RSV) infection and shingles are two viral diseases that affect older adults, and a combined vaccine to protect against both could be beneficial. RSV infection causes hospitalisations and significant morbidity in both children and adults and can be fatal in the elderly. The RSV fusion (F) envelope glycoprotein induces a strong RSV-neutralising antibody response and is the target of protective immunity in the first RSV vaccine for older adults, recently approved by the FDA. An initial childhood infection with the varicella zoster virus (VZV) results in chickenpox disease, but reactivation in older adults can cause shingles. This reactivation in sensory and autonomic neurons is characterized by a skin-blistering rash that can be accompanied by prolonged pain. The approved protein-in-adjuvant shingles vaccine induces VZV glycoprotein E (gE)-fspecific antibody and CD4+ T cell responses and is highly effective. Here we report the evaluation of RSV/shingles combination vaccine candidates based on non-replicating chimpanzee adenovirus (ChAd) vectors. We confirmed the cellular and humoral immunogenicity of the vaccine vectors in mice using T cell and antibody assays. We also carried out an RSV challenge study in cotton rats which demonstrated protective efficacy following a homologous prime-boost regimen with our preferred vaccine candidate.

Comparative Cost-Effectiveness Analysis of Respiratory Syncytial Virus Vaccines for Older Adults in Hong Kong

Two respiratory syncytial virus (RSV) vaccines (AREXVY® and ABRYSVO®) were recently approved for older adults in the US. This study aimed to evaluate the cost-effectiveness of AREXVY® and ABRYSVO® from the Hong Kong public healthcare provider's perspective. A two-year decision-analytical model was developed to examine the outcomes of a single RSV vaccination (AREXVY® or ABRYSVO®) compared to no vaccination. Primary outcomes included RSV-related health outcomes, direct medical costs, quality-adjusted life-year (QALY) loss, and incremental cost per QALY (ICER). RSV vaccines are not yet marketed in Hong Kong, base-case analysis, therefore, benchmarked US RSV vaccine prices at 4 levels (25%, 50%, 75%, 100%). AREXVY® and ABRYSVO® (versus no vaccination) gained 0.000568 QALY and 0.000647 QALY, respectively. ICERs of ABRYSVO® (26,209 USD/QALY) and AREXVY® (47,485 USD/QALY) were lower than the willingness-to-pay threshold (49,594 USD/QALY) at 25% US vaccine price. The RSV attack rate was a common influential factor at all vaccine price levels. The probabilities of AREXVY® and ABRYSVO® to be most cost-effective were 0.10% and 97.68%, respectively, at 25% US vaccine price. Single vaccination of ABRYSVO® or AREXVY® for older adults appears to gain QALYs over 2 years in Hong Kong. The cost-effectiveness of AREXVY® and ABRYSVO® is subject to vaccine price and RSV attack rate.

Risk and Benefit of mRNA COVID-19 Vaccines for the Omicron Variant by Age, Sex, and Presence of Comorbidity: A Quality-Adjusted Life Years Analysis

The development of the mutant omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the coronavirus disease 2019 (COVID-19) pandemic raised the importance of reevaluating the risk and benefit of COVID-19 vaccines. With a decision tree model, we calculated the benefit-risk ratio and the benefit-risk difference of receiving monovalent messenger RNA (mRNA) COVID-19 vaccine (primary 2 doses, a third dose, and a fourth dose) in the 4-5 months after vaccination using quality-adjusted life years. The analysis was stratified by age, sex, and the presence of comorbidity. Evidence from peer-reviewed publications and gray literature was reviewed on September 16, 2022, to inform the study. Benefit-risk ratios for receipt of the BNT162b2 vaccine (Pfizer-BioNTech) ranged from 6.8 for males aged 12-17 years without comorbidity for the primary doses to 221.3 for females aged ≥65 years with comorbidity for the third dose. The benefit-risk ratios for receipt of the mRNA-1273 vaccine (Moderna) ranged from 7.2 for males aged 18-29 years without comorbidity for the primary doses to 101.4 for females aged ≥65 years with comorbidity for the third dose. In all scenarios of the one-way sensitivity analysis, the benefit-risk ratios were more than 1, irrespective of age, sex, comorbidity status, and type of vaccine, for both primary and booster doses. The benefits of mRNA COVID-19 vaccines in protecting against the omicron variant outweigh the risks, irrespective of age, sex, and comorbidity.

Recombinant zoster vaccine (RZV) second-dose series completion in adults aged 50-64 years in the United States

In 2018, CDC recommended a highly efficacious adjuvanted recombinant zoster vaccine (RZV) as a 2-dose series for prevention of herpes zoster (HZ) for immunocompetent persons age ≥ 50 years, with the 2nd dose recommended 2-6 months after the 1st dose. We estimated second-dose RZV series completion in the U.S. among 50-64-year-olds using two administrative databases. Second-dose RZV series completion was ∼70% within 6-months and 80% within 12-months of first dose. Among those who received only 1 RZV dose with at least 12 months of follow-up time, 96% had a missed opportunity for a second-dose vaccination, defined as a provider or pharmacy visit, among whom 36% had a visit for influenza or pneumococcal vaccination within 2-12 months of their first-dose of RZV. We found that RZV series completion rates in 50-64-year-olds was high. Availability of RZV at pharmacies has potentially helped increase series completion, but missed opportunities remain.

Associations between vaccination and quality of life among Taiwan general population: A comparison between COVID-19 vaccines and flu vaccines

The COVID-19 pandemic has profoundly impacted lives worldwide and has led to global vaccination against COVID-19. However, there are concerns about the adverse effects of such vaccines on individuals' health. Therefore, it is important to investigate the association between vaccination and holistic health outcome (i.e., quality of life [QoL]). The present study analyzed data from the Taiwan Social Change Survey (TSCS), a survey conducted utilizing stratified random sampling. More specifically, data (N = 1425; 47.44% males; mean age = 50.58 y) on their vaccinations (including COVID-19 and flu vaccines) and QoL (using the Short-Form 12) were used. Participants were separated into two age subgroups for analyses (those aged below 50 y, and those 50 y or above). For participants aged below 50 y, those who received COVID-19 vaccine and those who received both COVID-19 and flu vaccines had significantly better physical QoL than those who did not receive any vaccination. Mental QoL was not significantly associated with vaccinations for participants aged below 50 y. Moreover, neither mental nor physical QoL was significantly associated with vaccinations for those aged 50 y or above. The present study showed that not having COVID-19 and flu vaccinations is associated with poor QoL. This finding should be disseminated to the public to help aid vaccination promotion.

Safety and reactogenicity of the adjuvanted recombinant zoster vaccine: experience from clinical trials and post-marketing surveillance

An adjuvanted recombinant zoster vaccine (RZV) is licensed for the prevention of herpes zoster. This paper reviews its safety and reactogenicity. A pooled analysis of two pivotal randomized Phase-3 trials (NCT01165177, NCT01165229) in adults ⩾50 years found that more solicited adverse events (AEs) were reported with RZV than placebo. Injection site pain was the most common solicited AE (RZV: 78.0% participants; placebo: 10.9%). Grade-3 pain occurred in 6.4% of RZV and 0.3% of placebo recipients. Myalgia, fatigue, and headache were the most commonly reported general solicited AEs (RZV: 44.7%, 44.5%, and 37.7%, respectively; placebo: 11.7%, 16.5%, and 15.5%, respectively). Most symptoms were mild to moderate in intensity with a median duration of 2–3 days. The intensity of reactogenicity symptoms did not differ substantially after the first and second vaccine doses. The pooled analysis of the pivotal Phase-3 trials did not identify any clinically relevant differences in the overall incidence of serious adverse events (SAEs), fatal AEs or potential immune-mediated diseases (pIMDs) between RZV and placebo. Reactogenicity in five studies of immunocompromised patients ⩾18 years (autologous stem cell transplant, human immunodeficiency virus, solid tumors, hematological malignancies, and renal transplant; NCT01610414, NCT01165203, NCT01798056, NCT01767467, and NCT02058589) was consistent with that observed in the pivotal Phase-3 trials. There were no clinically relevant differences between RZV and placebo in the immunocompromised populations with regard to overall incidence of SAEs, fatal AEs, pIMDs, or AEs related to patients’ underlying condition. Post-marketing surveillance found that the most commonly reported AEs were consistent with the reactogenicity profile of the vaccine in clinical trials. Overall, the clinical safety data for RZV are reassuring.

Headache After Vaccination: An Update on Recent Clinical Trials and Real-World Reporting

PURPOSE OF REVIEW

The aim of this review is to characterize headache as a vaccine adverse event (VAE) in clinical trials.

RECENT FINDINGS

Of the recent phase III vaccine RCTs (non-COVID-19), 53 studies reported on headache (13 infectious agents). The median rate (interquartile range) of headache was 15.6% (IQR: 9.6-37.6%). Of these, 24.5% of the RCTs reported headache greater in the vaccine group compared to the placebo/control group. In the herpes zoster vaccination trials, headache was more common in all active groups: median rate 33.9% (IQR: 29.7-40.5%) as compared to placebo: median rate 17.7% (IQR: 15.4-23.8%). Influenza and HPV vaccination trials were the 2nd and 3rd most common to have headache as a VAE. Of the 6 widely distributed COVID-19 vaccinations, median rate of post-vaccination headache was 39% (IQR: 28-50%). Headache is a common VAE in vaccine trials. Standardized grading methods, predictors of persistence, and treatment regimens are warranted.

Vaccines

The safety of COVID-19 vaccines, as was the case last year, remains a large part of the focus in this volume. COVID-19 placed a large magnifying glass on both vaccines, specifically vaccine safety. This was most readily apparent as the number of records in VAERS ballooned to about 10 times the size from 2020 to 2021 (Vaccine Adverse Event Reporting System (VAERS), 2022) [S]. While we have added and/or improved VAERS during COVID-19, including adding or improving other vaccine safety surveillance tools like v-safe and vaccine safety datalink (Blumenthal, Phadke, et al., 2021) [MC], there is still room for improvement in these pharmacovigilance tools (Rizk et al., 2021) [r]. A major global initiative in this realm is the Global Vaccines Safety Blueprint 2.0 (GVSB2.0) (Organization, 2021, pp. 2021–2023) [S]. We wholeheartedly endorse these initiatives, which could significantly improve vaccine safety.

As noted in past SEDA issues, clinicians should be mindful of the risks of AEs and SAEs associated with each individual vaccine.

Safety, tolerability, and immunogenicity of V114, a 15-valent pneumococcal conjugate vaccine, followed by sequential PPSV23 vaccination in healthy adults aged ≥50 years: A randomized phase III trial (PNEU-PATH)

BACKGROUND

Streptococcus pneumoniae causes pneumococcal disease, and older adults are at an increased risk. Sequential vaccination of 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended for broad protection against pneumococcal disease in some countries.

METHODS

This phase III trial evaluated the safety, tolerability, and immunogenicity of sequential administration of either V114 (a 15-valent PCV containing serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, and 33F) or PCV13, followed 12 months later by PPSV23, in healthy adults aged ≥50 years (NCT03480763). A total of 652 participants were randomized 1:1 to receive either V114 or PCV13, followed by PPSV23.

RESULTS

The most common solicited adverse events (AEs) following PCV vaccination included injection-site pain and fatigue. Higher proportions of participants with these events were observed in the V114 group following PCV; however, these differences were not clinically significant. Following PPSV23 vaccination, the most common solicited AEs were injection-site pain and injection-site swelling; the proportions of participants with these events were comparable between both groups. Incidence of serious AEs was low in both groups following PCV and PPSV23, and none were related to study vaccines. No deaths occurred during the study. Serum opsonophagocytic activity geometric mean titers and immunoglobulin G geometric mean concentrations were comparable between both groups for all 15 serotypes in V114 following PPSV23. Immune responses elicited by V114 persisted for at least 12 months. Immune responses at 30 days and 12 months post-vaccination with PCV were comparable between both groups for the 13 shared serotypes and higher in the V114 group for the V114-unique serotypes (22F and 33F).

CONCLUSION

Administration of V114 followed by PPSV23 was well tolerated and induced comparable antibody levels to PCV13 followed by PPSV23 in healthy adults aged ≥50 years.

Considering Frailty in SARS-CoV-2 Vaccine Development: How Geriatricians Can Assist

The COVID-19 pandemic has disproportionately impacted frail older adults, especially residents of long-term care (LTC) facilities. This has appropriately led to prioritization of frail older adults and LTC residents, and those who care for them, in the vaccination effort against COVID-19. Older adults have distinct immunological, clinical, and practical complexity, which can be understood through a lens of frailty. Even so, frailty has not been considered in studies of COVID-19 vaccines to date, leading to concerns that the vaccines have not been optimally tailored for and evaluated in this population even as vaccination programs are being implemented. This is an example of how vaccines are often not tested in Phase 1/2/3 clinical trials in the people most in need of protection. We argue that geriatricians, as frailty specialists, have much to contribute to the development, testing and implementation of COVID-19 vaccines in older adults. We discuss roles for geriatricians in ten stages of the vaccine development process, covering vaccine design, trial design, trial recruitment, establishment and interpretation of illness definitions, safety monitoring, consideration of relevant health measures such as frailty and function, analysis methods to account for frailty and differential vulnerability, contributions in regulatory and advisory roles, post-marketing surveillance, and program implementation and public health messaging. In presenting key recommendations pertinent to each stage, we hope to contribute to a dialogue on how to push the field of vaccinology to embrace the complexity of frailty. Making vaccines that can benefit frail older adults will benefit everyone in the fight against COVID-19.

Early examination of real-world uptake and second-dose completion of recombinant zoster vaccine in the United States from October 2017 to September 2019

Shingrix (Recombinant zoster vaccine, RZV) was approved in October 2017 in the United States (US) for the prevention of herpes zoster in adults aged 50 years and older. The vaccine is administered in two doses, with the second dose administration recommended between two and six months after the first dose. Examination of uptake and series completion is important to ensure appropriate use, especially at the time of vaccine introduction. This report provides demographic characteristics of patients receiving RZV between October 2017 and September 2019, first- and second-dose uptake, and a cumulative estimation of second-dose completion by month for US adults aged 50 years and older. Monthly uptake increased rapidly since October 2017; overall, 7,097,441 first doses of RZV were administered along with 4,277,636 second doses during the observed timeframe. Among people with an observed first-dose administration, 70% and 80% completed the two-dose series within six and 12 months post initial dose, respectively. This evidence suggests that RZV has rapidly been adopted by a large population in the US and most are following manufacturer or policy recommendations regarding series completion. Further analyses are needed to explore potential patient, provider, and policy-relevant characteristics associated with second-dose completion that could serve as targets for further improvement.

Impact of Reactogenicity After Two Doses of Recombinant Zoster Vaccine Upon Physical Functioning and Quality of Life: An Open Phase III Trial in Older Adults

BACKGROUND

Herpes zoster may significantly impact quality of life (QoL) in older adults. The recombinant zoster vaccine (RZV) is efficacious in adults aged ≥50 and older and is associated with increased reactogenicity compared to placebo. We report here on the impact of reactogenicity of the second RZV dose on the QoL and physical functioning (PF) of vaccine recipients, and summarize findings following both doses.

METHOD

In this single-arm study, 401 adults aged ≥50 and older were enrolled to receive two RZV doses 2 months apart. Change in mean Short Form Survey-36 (SF-36) PF and EuroQol-5 Dimension (EQ-5D) scores, reactogenicity, safety, productivity loss, and healthcare resource utilization were evaluated.

RESULTS

In total, 391 (97.5%) participants received dose 2. Post-dose 2, the most common solicited local symptoms were injection site pain (75.1%), erythema (22.4%), and swelling (13.9%), and the most common systemic symptoms were fatigue (46.3%), headache (37.5%), and myalgia (32.9%). Grade 3 solicited (local and systemic) adverse events were reported by 61 (15.6%) participants and were associated with a transient clinically significant decrease in SF-36 PF score on Days 1-2 post-dose 2 that recovered by Day 3. Overall, no clinically important reduction in mean SF-36 PF scores was observed from baseline to post-dose 2 (mean change -0.4), and no quality-adjusted-life-year loss was recorded.

CONCLUSIONS

Overall, QoL and PF of RZV vaccinees were not affected by vaccine-related reactogenicity. A transient reduction was observed in the first 2 days after RZV vaccination in individuals with Grade 3 adverse events. No safety concerns were identified.

Patient-reported outcomes in vaccines research: relevance for decision-making

The development and demand for effective vaccines have witnessed an exponential growth over the last century. In the meantime, the vaccine market involves more knowledgeable stakeholders, with a shift in emphasis by regulatory agencies on understanding the patient perception and experience. The Food and Drug Administration's publication of the patient-reported outcomes (PRO) guidance has elevated the discipline of PROs and has resulted in a transition from clinician reports of patient outcomes to PROs. This review reports various research methods, which utilize PROs, including qualitative and quantitative research, clinical trials, and patient preference studies. With the advancement of electronic PRO data capture, additional advantages of PROs are being observed and utilized (e.g. as a trigger for clinical endpoints). We discuss uses and advantages of including PROs into the clinical trial program to improve efficiencies, clinical relevance and overall validity of the program in the vaccine field. (See Plain Language Summary).

Vaccines

In this volume of the Side Effects of Drugs Annual, although other vaccines will be covered, the safety of COVID vaccines is the focus as COVID-19 has led to heightened attention on vaccine safety in general. As such, this chapter will be more relevant than ever before. As noted in past SEDA issues, clinicians should be mindful of the risks of AEs and SAEs associated with each vaccine.

Post hoc analysis of reactogenicity trends between dose 1 and dose 2 of the adjuvanted recombinant zoster vaccine in two parallel randomized trials

In two large clinical trials (ZOE-50 [NCT01165177] and ZOE-70 [NCT01165229]), two doses of the adjuvanted recombinant zoster vaccine (RZV) demonstrated >90% efficacy against herpes zoster in adults ≥50 years of age. Solicited adverse events (AEs) were collected for 7 days post-each dose in a study sub-cohort. The incidence of reported solicited AEs was higher for RZV compared to placebo recipients. Since reactogenicity may contribute to a person's willingness to be vaccinated, knowing about expected reactogenicity might help keep high compliance with the second dose. This post hoc analysis assessed the intensity of solicited AEs post-dose 2 reported to the same event's intensity post-dose 1. Intensity was graded from 0 to 3, grade 3 indicating the highest severity. Of the vaccinees who did not experience a specific AE post-dose 1, 72.6-91.7% did not experience the same event after dose 2. Although the frequency of grade 3 AEs post-dose 2 was the highest in participants reporting the same AEs at grade 3 post-dose 1, 65.8-89.3% of vaccinees with grade 3 specific AEs post-dose 1 reported the same AEs at lower intensity post-dose 2. These data can help inform health-care professionals about the frequency and intensity of AEs post-dose 2 with respect to post-dose 1.

Evaluation of two frailty indices, with practical application in a vaccine clinical trial

Frail older adults are at increased risk of poor clinical outcomes. Frailty assessment is therefore important in clinical trials to understand the benefits and harms of interventions. However, consensus is lacking on how frailty should be assessed.We developed a prospectively specified index using a battery of formal tests and instruments and a retrospectively generated index using medical comorbidities and patient reported outcomes (PROs) within an adjuvanted recombinant zoster vaccine (RZV) trial (NCT02979639). For both frailty indices (FIs), a total deficit score was calculated as the accumulation of deficits and participants were categorized as non-frail, pre-frail and frail. We assessed (1) the feasibility and validity of both FIs; (2) the impact of RZV vaccine reactogenicity by frailty status on Short Form-36 [SF-36] physical functioning (PF) scores.Of 401 participants, aged ≥50 years, 236 (58.9%) were categorized non-frail, 143 (35.7%), pre-frail, and 22 (5.5%) frail using the prospective FI. Corresponding numbers for the retrospective FI were 192 (47.9%), 169 (42.1%) and 40 (10.0%), respectively. Strong concordance was observed between the frailty status assessments (P < .001). The proportion defined as frail increased from 1.5%, to 10.4% in participants aged 50-59, and ≥70 years, respectively, for the prospective FI. Corresponding numbers for the retrospective FI were 3.7%, and 17.2%, respectively. RZV vaccination was associated with a transient, non-clinically meaningful, decrease on the SF-36 PF score in frail participants.Both frailty indices provided similar results. The retrospectively generated FI offers the advantage of being easier to incorporate into vaccine clinical trials of older adults.