Comparative Postmarket Safety Profile of Adjuvanted and High-Dose Influenza Vaccines in Individuals 65 Years or Older

Characteristics and factors of repeated influenza vaccination among elderly individuals in Shanghai, China from 2020 to 2022

Elderly individuals face a high risk of hospitalization and death related to influenza, thus prioritizing them for influenza vaccination. Due to variations in the influenza virus and waning protective antibodies, annual influenza vaccination is recommended. However, research on repeated influenza vaccination among elderly individuals in China is limited. From 2020 to 2022, the average influenza vaccination coverage among registered elderly individuals in Shanghai was 4.1%, showing a declining trend over time. In 2020, the rate of repeated influenza vaccination among elderly individuals was 28.35%, which rose to almost two-thirds both in 2021 and 2022. No increased risk of adverse events following immunization was observed after repeated influenza vaccination during this period. Our study also found that elderly individuals with Shanghai household registration, managed by community clinics, and older age tended to receive more doses of repeated influenza vaccination throughout the period from 2020 to 2022. Increasing influenza vaccine coverage among elderly individuals in Shanghai is both urgent and challenging. Health authorities should intensify educational and promotional campaigns to encourage uptake of annual repeated influenza vaccination among elderly individuals.

Current Approaches in Postapproval Vaccine Safety Studies Using Real-World Data: A Systematic Review of Published Literature

PURPOSE

Well-designed observational postmarketing studies using real-world data (RWD) are critical in supporting an evidence base and bolstering public confidence in vaccine safety. This systematic review presents current research methodologies in vaccine safety research in postapproval settings, technological advancements contributing to research resources and capabilities, and their major strengths and limitations.

METHODS

A comprehensive search was conducted using PubMed to identify relevant articles published from January 1, 2019, to December 31, 2022. Eligible studies were summarized overall by study design and other study characteristics (eg, country, vaccine studied, types of data source, and study population). An in-depth review of select studies representative of conventional or new designs, analytical approaches, or data collection methods was conducted to summarize current methods in vaccine safety research.

FINDINGS

Out of 977 articles screened for inclusion, 135 were reviewed. The review shows that recent advancements in scientific methods, digital technology, and analytic approaches have significantly contributed to postapproval vaccine safety studies using RWD. "Near real-time surveillance" using large datasets (via collaborative or distributed databases) has been used to facilitate rapid signal detection that complements passive surveillance. There was increasing appreciation for self-controlled case-only designs (self-controlled case series and self-controlled risk interval) to assess acute-onset safety outcomes, artificial intelligence, and natural language processing to improve outcome accuracy and study timeliness and emerging artificial intelligence-based analysis to capture adverse events from social media platforms.

IMPLICATIONS

Continued development in the area of vaccine safety research methodologies using RWD is warranted. The future of successful vaccine safety research, especially evaluation of rare safety events, is likely to comprise digital technologies including linking RWD networks, machine learning, and advanced analytic methods to generate rapid and robust real-world safety information.

Cost-Effectiveness of Vaccination of Older Adults with an MF59®-Adjuvanted Quadrivalent Influenza Vaccine Compared to Standard-Dose and High-Dose Vaccines in Denmark, Norway, and Sweden

Individuals aged 65 years and above are at increased risk of complications and death from influenza compared with any other age group. Enhanced vaccines, as the MF59®-adjuvanted quadrivalent influenza vaccine (aQIV) and the high-dose quadrivalent influenza vaccine (HD-QIV), provide increased protection for older adults in comparison to the traditional standard-dose quadrivalent influenza vaccines (SD-QIV). This study aimed to assess the cost-effectiveness of aQIV compared to SD-QIV and HD-QIV in Denmark, Norway, and Sweden for adults aged ≥65 years. A static decision tree model was used to evaluate costs and outcomes of different vaccination strategies from healthcare payer and societal perspectives. This model projects that compared to SD-QIV, vaccination with aQIV could prevent a combined total of 18,772 symptomatic influenza infections, 925 hospitalizations, and 161 deaths in one influenza season across the three countries. From a healthcare payer perspective, the incremental costs per quality adjusted life year (QALY) gained with aQIV versus SD-QIV were EUR 10,170/QALY in Denmark, EUR 12,515/QALY in Norway, and EUR 9894/QALY in Sweden. The aQIV was cost saving compared with HD-QIV. This study found that introducing aQIV to the entire population aged ≥65 years may contribute to reducing the disease and economic burden associated with influenza in these countries.

Enhanced passive safety surveillance of the MF59-adjuvanted quadrivalent influenza vaccine in the elderly during the 2021/22 influenza season

In accordance with European directives, each year the enhanced safety surveillance (ESS) of seasonal influenza vaccines should be conducted in order to detect any potential increase in reactogenicity when the vaccine composition is updated or a new formulation becomes available. The objective of this passive ESS (EPSS) was to assess the frequency of spontaneously reported adverse events (AEs) following vaccination with the 2021/22 formulation of the MF59-adjuvanted quadrivalent influenza vaccine (aQIV) among older adults in Italy through the collection of data within a short time period (start of seasonal influenza vaccination) in order to monitor the reactogenicity of aQIV early in the season. All AEs reported within seven days following vaccination were analyzed by type and seriousness. In all, 1,059 vaccination cards were distributed to individuals aged ≥65 years. Only one, non-serious, spontaneous individual case safety report was submitted, yielding an overall rate of 0.9 per 1,000 doses administered. This report consisted of a reactogenic AE of pyrexia. The EPSS confirmed that the reactogenicity profile of aQIV was consistent with the known safety profile of the previous trivalent formulation. These optimal safety data could bolster public confidence in influenza vaccination and help to improve vaccination coverage.

Information systems for vaccine safety surveillance

Immunization implementation in the community relies upon post-licensure vaccine safety surveillance to maintain safe vaccination programs and to detect rare AEFI not observed in clinical trials. The increasing availability of electronic health-care related data and correspondence from both health-related providers and internet-based media has revolutionized health-care information. Many and varied forms of health information related to adverse event following immunization (AEFI) are potentially suitable for vaccine safety surveillance. The utilization of these media ranges from more efficient use of electronic spontaneous reporting, automated solicited surveillance methods, screening various electronic health record types, and the utilization of natural language processing techniques to scan enormous amounts of internet-based data for AEFI mentions. Each of these surveillance types have advantages and disadvantages and are often complementary to each other. Most are "hypothesis generating," detecting potential safety signals, where some, such as vaccine safety datalinking, may also serve as "hypothesis testing" to help verify and investigate those potential signals.

A scoping review of active, participant-centred, digital adverse events following immunization (AEFI) surveillance: A Canadian immunization research network study

BACKGROUND

Post-licensure adverse events following immunization (AEFI) surveillance is conducted to monitor vaccine safety, such as identifying batch/brand issues and rare reactions, which consequently improves community confidence. The integration of technology has been proposed to improve AEFI surveillance, however, there is an absence of description regarding which digital solutions are successfully being used and their unique characteristics.

OBJECTIVES

The objectives of this scoping review were to 1) map the research landscape on digital systems used for active, participant-centred, AEFI surveillance and 2) describe their core components.

METHODS

We conducted a scoping review informed by the PRISMA Extension for Scoping Reviews (PRSIMA-ScR) guideline. OVID-Medline, Embase Classic + Embase, and Medrxiv were searched by a medical librarian from January 1, 2000 to January 28th, 2021. Two independent reviewers determined which studies met inclusion based on pre-specified eligibility criteria. Data extraction was conducted using pre-made tables with specific variables by one investigator and verified by a second.

RESULTS

Twenty-seven publications met inclusion, the majority of which came from Australia (n = 15) and Canada (n = 6). The most studied active, participant-centred, digital AEFI surveillance systems were SmartVax (n = 8) (Australia), Vaxtracker (n = 7) (Australia), and Canadian National Vaccine Safety (CANVAS) Network (Canada) (n = 6). The two most common methods of communicating with vaccinees reported were short-message-service (SMS) (n = 15) and e-mail (n = 14), with online questionnaires being the primary method of data collection (n = 20).

CONCLUSION

Active, participant-centred, digital AEFI surveillance is an area actively being researched as depicted by the literature landscape mapped by this scoping reviewWe hypothesize that the AEFI surveillance approach herein described could become a primary method of collecting self-reported subjective symptoms and reactogenicity from vaccinees, complementing existing systems. Future evaluation of identified digital solutions is necessary to bring about improvements to current vaccine surveillance systems to meet contemporary and future public health needs.

Adverse events following influenza immunization: understanding the role of age and sex interactions

BACKGROUND

Reduction of adverse events following immunization (AEFI) could improve vaccine uptake. Evidence suggests sex and age affect AEFI rates but, with limited understanding of their interaction, groups at higher risk for adverse reaction cannot be identified.

RESEARCH DESIGN AND METHODS

Using deidentified data (n = 308,481) from Australians receiving influenza vaccinations in the 2020 calendar year, we analyzed the effects of independent predictors (i.e. age and sex), on experiencing an AEFI using logistic regression generalized additive modeling to capture any nonlinear relationships and adjusting for vaccine brand and concomitant vaccination.

RESULTS

The overall reaction rate was 5.5%. Modeling revealed significant effects of age (p < 0.001), sex (p < 0.001), and age × sex (p < 0.001). Females were more likely than males to experience AEFIs between 7.5 and 87.5 years of age and exhibited peak odds at about 53 years, while peak odds for males occurred in infancy.

CONCLUSION

The results suggest there is a need for targeting AEFI reduction in females, particularly in 30-70-year-olds, to improve the vaccination experience. The results further suggest that reducing concomitant vaccination and choosing less reactogenic vaccine brands could reduce risk of AEFI, however, retaining concomitant vaccination may optimize vaccine uptake.

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.

Assessing Vaccine Protection for Older Adults with Diabetes: A Systematic Review

Immunosenescence and comorbidities increase the susceptibility of older adults with diabetes mellitus (DM) to vaccine-preventable diseases, hospitalization, disability, or death. This systematic review synthesizes research on protecting older adults with DM during pandemics, exploring vaccine safety, tolerance, and vaccination uptake by older adults in anticipation of seasonal influenza outbreaks during the current COVID-19 threat. Addressed were: (a) age-related factors influencing the effectiveness of vaccines against infectious disease in older adults; (b) vaccine safety, tolerance, effectiveness for older persons with DM; and (c) issues affecting older adults accepting immunization recommendations. Medline and CINAHL databases yielded 214 studies with 43 meeting inclusion criteria (32 descriptive and 11 controlled trials). Findings show altered glycemic control stimulates proinflammatory mediators, increasing infection risk, vaccines, and annual revaccinations safely reduce hospitalization rates, mortality outcomes, without affecting glycemic control. However, vaccines fail to evoke optimal antibody responses in older adults. Unawareness, fear of side effects, tend to lower vaccination participation.

Safety of live attenuated herpes zoster vaccine in Australian adults 70-79 years of age: an observational study using active surveillance

OBJECTIVES

To assess the safety of live attenuated herpes zoster vaccine live (ZVL) through cumulative analysis of near real-time, participant-based active surveillance from Australia's AusVaxSafety system.

DESIGN AND SETTING

ZVL was funded in Australia for adults aged 70 years from November 2016, with a time-limited catch up programme for those up to 79 years. This cohort study monitored safety in the first two programme years through active surveillance at 246 sentinel surveillance immunisation sites.

PARTICIPANTS

Adults aged 70-79 years vaccinated with ZVL who responded to an opt-out survey sent via automated short message service (SMS) 3 days following vaccination (n=17 458) or contributed supplementary data through a separate, opt-in online survey at 16 and 24 days following vaccination (n=346).

PRIMARY AND SECONDARY OUTCOME MEASURES

Rates of overall and prespecified adverse events following immunisation (AEFI) by sex, concomitant vaccination and underlying medical condition. Signal detection methods (fast initial response cumulative summation and Bayesian updating analyses) were applied to reports of medical attendance.

RESULTS

The median age of participants was 72 years; 53% were female. The response rate following automated SMS was high (73% within 7 days of vaccination). Females were more likely than males to report any adverse event within 7 days of vaccination (RR 2.07, 95% CI 1.86 to 2.31); injection site reaction was the most commonly reported (2.3%, n=377). Concomitant vaccination was not associated with higher adverse event rates (RR 1.05, 95% CI 0.93 to 1.18). Rates of medical attendance were low (0.3%) with no safety signals identified. Supplementary opt-in survey data on later onset adverse events did not identify any difference in AEFI rates between those with and without underlying medical conditions.

CONCLUSIONS

ZVL has a very good safety profile in the first week after vaccination in older adults. Active, participant-based surveillance in this primary care cohort is an effective method to monitor vaccine safety among older adults and will be used as a key component of COVID-19 vaccine safety surveillance in Australia.

Safety, Reactogenicity, and Health-Related Quality of Life After Trivalent Adjuvanted vs Trivalent High-Dose Inactivated Influenza Vaccines in Older Adults: A Randomized Clinical Trial

IMPORTANCE

Trivalent adjuvanted inactivated influenza vaccine (aIIV3) and trivalent high-dose inactivated influenza vaccine (HD-IIV3) are US-licensed for adults aged 65 years and older. Data are needed on the comparative safety, reactogenicity, and health-related quality of life (HRQOL) effects of these vaccines.

OBJECTIVE

To compare safety, reactogenicity, and changes in HRQOL scores after aIIV3 vs HD-IIV3.

DESIGN, SETTING, AND PARTICIPANTS

This randomized blinded clinical trial was a multicenter US study conducted during the 2017 to 2018 and 2018 to 2019 influenza seasons. Among 778 community-dwelling adults aged at least 65 years and assessed for eligibility, 13 were ineligible and 8 withdrew before randomization. Statistical analysis was performed from August 2019 to August 2020.

INTERVENTIONS

Intramuscular administration of aIIV3 or HD-IIV3 after age-stratification (65-79 years; ≥80 years) and randomization.

MAIN OUTCOMES AND MEASURES

Proportions of participants with moderate-to-severe injection-site pain and 14 other solicited reactions during days 1 to 8, using a noninferiority test (5% noninferiority margin), and serious adverse events (SAE) and adverse events of clinical interest (AECI), including new-onset immune-mediated conditions, during days 1 to 43. Changes in HRQOL scores before and after vaccination (days 1, 3) were also compared between study groups.

RESULTS

A total of 757 adults were randomized, 378 to receive aIIV3 and 379 to receive HD-IIV3. Of these participants, there were 420 women (55%) and 589 White individuals (78%) with a median (range) age of 72 (65-97) years. The proportion reporting moderate-to-severe injection-site pain, limiting or preventing activity, after aIIV3 (12 participants [3.2%]) (primary outcome) was noninferior compared with HD-IIV3 (22 participants [5.8%]) (difference -2.7%; 95% CI, -5.8 to 0.4). Ten reactions met noninferiority criteria for aIIV3; 4 (moderate-to-severe injection-site tenderness, arthralgia, fatigue, malaise) did not. It was inconclusive whether these 4 reactions occurred in higher proportions of participants after aIIV3. No participant sought medical care for a vaccine reaction. No AECI was observed. Nine participants had at least SAE after aIIV3 (2.4%; 95% CI,1.1% to 4.5%); 3 had at least 1 SAE after HD-IIV3 (0.8%; 95% CI, 0.2% to 2.2%). No SAE was associated with vaccination. Changes in prevaccination and postvaccination HRQOL scores were not clinically meaningful and not different between the groups.

CONCLUSIONS AND RELEVANCE

Overall safety and HRQOL findings were similar after aIIV3 and HD-IIV3, and consistent with prelicensure data. From a safety standpoint, this study's results support using either vaccine to prevent influenza in older adults.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03183908.

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.

Consumer acceptability and validity of m-Health for the detection of adverse events following immunization - The Stimulated Telephone Assisted Rapid Safety Surveillance (STARSS) randomised control trial

INTRODUCTION

Monitoring for adverse events following immunisation (AEFI) is critical for vaccine pharmacovigilance. Given the global and expanding availability of mobile phones their utility for consumer-based vaccine safety surveillance is of interest but little is known about consumer acceptability. This study nested within the Stimulated Telephone Assisted Rapid Safety Surveillance (STARSS) randomised control trial sought to evaluate the acceptability of SMS for AEFI surveillance.

METHODS

The primary STARSS study was a multi-centre RCT evaluating the efficacy of repeated SMS prompts for AEFI surveillance with participants being adult vaccinees or parents of children receiving any vaccine. This nested study enrolled primary RCT participants who completed a detailed computer assisted telephone interview to determine their attitudes towards SMS-based surveillance and ascertain their knowledge and attitudes toward vaccine safety, efficacy, data privacy and use of electronic health records. Attitudes to surveillance and related behaviour were used as measures of acceptability.

RESULTS

20% (1200/6555) of the participants were enrolled and 1139 completed the full-length questionnaire. 96% indicated that SMS-based surveillance after immunisation to check the safety of the vaccine "should be done" but 62% of all respondents said it should be done but consent should be sought first. Neither vaccine safety attitudes nor attitudes toward privacy were associated with opposition to SMS-based surveillance. In terms of SMS related behaviour demographic rather than attitudinal factors were associated with non-compliance.

CONCLUSION

Overall, the attitude towards SMS-based surveillance was very favourable. Experiencing the SMS surveillance has the effect of reducing opposition to an SMS surveillance system, and at the same time increasing the likelihood of a preference for prior consent. Detection of a vaccine safety signal could be impeded in particular demographic groups who are non-compliant and we should undertake further research to understand why these groups are non-compliant and how this can be improved.

Efficacy of m-Health for the detection of adverse events following immunization - The stimulated telephone assisted rapid safety surveillance (STARSS) randomised control trial

INTRODUCTION

Passive surveillance is recommended globally for the detection of adverse events following immunisation (AEFI) but this has significant challenges. Use of Mobile health for vaccine safety surveillance enables a consumer-centred approach to reporting. The Stimulated Telephone Assisted Rapid Safety Surveillance (STARSS) a randomised control trial (RCT) sought to evaluate the efficacy and acceptability of SMS for AEFI surveillance.

METHODS

Multi-centre RCT, participants were adult vaccinees or parents of children receiving any vaccine at a trial site. At enrolment randomisation occurred to one of two SMS groups or a control group. Prompts on days 2, 7 and 14 post-immunisation, were sent to the SMS group, to ascertain if a medical event following immunisation (MEFI) had occurred. No SMS's were sent to the control participants. Those in the SMS who notified an MEFI were pre-randomised to complete a computer assisted telephone interview or a web based report to determine if an AEFI had occurred whilst an AEFI in the controls was determined by a search for passive reports. The primary outcome was the AEFI detection rate in the SMS group compared to controls.

RESULTS

We enrolled 6,338 participants, who were equally distributed across groups and who received 11,675 vaccines. The SMS group (4,225) received 12,675 surveillance prompts with 9.8% being non-compliant and not responding. In those that responded 90% indicated that no MEFI had been experienced and 184 had a verified AEFI. 6 control subjects had a reported AEFI. The AEFI detection rate was 13 fold greater in the SMS group when compared with controls (4.3 vs 0.3%).

CONCLUSION

We have demonstrated that the STARSS methodology improves AEFI detection. Our findings should inform the wider use of SMS-based surveillance which is particularly relevant since establishing robust and novel pharmacovigilance systems is critical to monitoring novel vaccines which includes potential COVID vaccines.