Active surveillance for safety monitoring of seasonal influenza vaccines in Italy, 2015/2016 season

The Effect of Sex on the Incidence, Latency, Duration and Perceived Burden of Adverse Events Following Seasonal Influenza Vaccination in the Netherlands

INTRODUCTION

The annual reformulation of the seasonal influenza vaccine results in fluctuating frequencies and severity of adverse effects following immunization (AEFIs), which stresses the importance of pharmacovigilance. Also, sex-related factors are known to influence the development of AEFIs. This study aims to describe the difference in incidence and course (i.e., time-to-onset, time-to-recovery, and perceived burden) of AEFIs between males and females after seasonal influenza vaccination.

METHODS

We assessed data from cohort event monitoring studies, which were performed over nine consecutive years (2013-2021), each covering several months during the seasonal influenza campaign in the Netherlands. Participants reported information about AEFIs over a 30-day period in three questionnaires. The effect of sex, age, body mass index, study year, and comorbidities on the incidence of any AEFI, local reactions, fever and the five most reported AEFIs was analyzed using logistic regression. The difference in time-to-onset, time-to-recovery, and perceived burden between males and females was analyzed by the Kruskal-Wallis test.

RESULTS

The cohort included 7789 participants (53.0% females). Females had around 2.5-fold (p < 0.001) higher odds of developing any AEFI compared with males. Some study years and comorbidities were positively associated with AEFI incidence, whereas age was negatively associated. An AEFI had a significant shorter time-to-onset, a longer time-to-recovery, and a higher perceived burden in females compared to males.

CONCLUSION

Overall, the results confirm that females experience AEFIs more often than males. Additionally, this study shows that the course of AEFIs only partially differs between the sexes.

Postmarketing observational study on the safety of 2021/2022 and 2022/2023 influenza vaccination campaigns in Italy: TheShinISS-Vax|Flu study protocol

INTRODUCTION

The purpose of TheShinISS-Vax|Flu study is to examine the association between influenza vaccines and adverse events requiring hospital admission or emergency care during the influenza vaccination campaigns 2021/2022 and 2022/2023 in Italy.

METHODS AND ANALYSIS

This is a Self-Controlled Case Series multiregional study using linked routinely collected data from regional healthcare databases of the participating regions. Study participants will be persons aged ≥6 months, unvaccinated or who have received influenza vaccine during the influenza vaccination campaigns in the seasons 2021/2022 and 2022/2023 in Italy and who have experienced the outcome of interest for the first time during the study period (1 September 2021-30 June 2022 and 1 September 2022-30 June 2023 for the first and second vaccination campaigns, respectively). Risk periods will be specifically defined for each outcome and further subdivided into periods of 7 days. The exposures will be the first or second dose of the influenza vaccines administered during the two vaccination campaigns. Statistical analysis will be conducted separately for the data of the two campaigns. Exposure risk period will be compared with baseline risk period defined as any time of observation out of the risk periods. The modified SCCS method will be applied to handle event-dependent exposure and mortality and fitted using unbiased estimating equations to estimate relative incidences and excess of cases per 100 000 vaccinated by dose, age, sex and type of vaccine. Calendar period will be included as time-varying confounder in the model, where appropriate.

ETHICS AND DISSEMINATION

The study received the approval from the National ethics committee for clinical trials of public research bodies and other national public institutions (PRE BIO CE n.0036723, 23/09/2022). Results will be published in peer-reviewed journals and reports in accordance with the publication policies of the Italian National Institute of Health and of the Italian Medicines Agency.

Differences and disparities in seasonal influenza vaccine, acceptance, adverse reactions, and coverage by age, sex, gender, and race

BACKGROUND

Influenza is a significant threat to public health worldwide. Despite the widespread availability of effective and generally safe vaccines, the acceptance and coverage of influenza vaccines are significantly lower than recommended. Sociodemographic variables are known to be potential predictors of differential influenza vaccine uptake and outcomes.

OBJECTIVES

This review aims to (1) identify how sociodemographic characteristics such as age, sex, gender, and race may influence seasonal influenza vaccine acceptance and coverage; and (2) evaluate the role of these sociodemographic characteristics in differential adverse reactions among vaccinated individuals.

METHODS

PubMed was used as the database to search for published literature in three thematic areas related to the seasonal influenza vaccine - vaccine acceptance, adverse reactions, and vaccine coverage.

RESULTS

A total of 3249 articles published between 2010 and 2020 were screened and reviewed, of which 39 studies were included in this literature review. By the three thematic areas, 17 studies assessed vaccine acceptance, 8 studies focused on adverse reactions, and 14 examined coverage of the seasonal influenza vaccine. There were also two studies that focused on more than one of the areas of interest.

CONCLUSION

Each of the four sociodemographic predictors - age, sex, race, and gender - were found to significantly influence vaccine acceptance, receipt and outcomes in this review.

Safety Profile of GSK's Inactivated Quadrivalent Seasonal Influenza Vaccine in Belgium, Germany and Spain: Passive Enhanced Safety Surveillance Study for the 2019/2020 Influenza Season

Introduction

Seasonal influenza infects millions annually in Europe. Annual influenza vaccination is the most effective measure to reduce the risk of infection and its complications, especially among young children and older adults.

Objective

We assessed adverse event (AE) frequency after receiving GSK’s inactivated quadrivalent seasonal influenza vaccine (IIV4).

Methods

A passive enhanced safety surveillance study was conducted in Belgium, Germany, and Spain. Adults who had received GSK's IIV4 or the parent(s)/guardian(s)/legally acceptable representative(s) of children given the vaccine were invited to complete an adverse drug reaction (ADR) card to document AEs experienced within 7 days post vaccination.

Results

A total of 1082 participants (51.6% females) received GSK's IIV4, including 115 children < 9 years of age who received two doses. The ADR card return rate was 97.0% (n = 1049) after dose 1 and 100% (n = 115) after dose 2. All participants in Belgium and Germany were adults. In Spain, 71.2% were children. After dose 1, 39.2% reported one or more AE. The most frequent AEs category was "general disorders and administration site conditions” (GDASC). AEs were most frequently reported in adults aged 18–65 years (47.2%), followed by children aged 6 months–17 years (38.1%), and adults aged > 65 years (31.6%). After dose 2, 7.8% reported one or more AE, and GDASC was again the most frequent AE category. There were no serious AEs related to GSK's IIV4 within 7 days post vaccination.

Conclusion

No serious AEs related to GSK’s IIV4 within 7 days post vaccination were reported. This study supports the favourable risk–benefit safety profile of GSK’s IIV4.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01121-8.

Seasonal influenza infects millions annually in Europe, especially young children and older adults. Annual influenza vaccination is the most effective measure to reduce the risk of infection and its complications. As the wild influenza virus strains change every year, the composition of the influenza vaccine changes as well. Since the vaccine is produced in the same way over the years, extensive safety studies are no longer required by regulatory authorities. Instead, monitoring of any unwanted medical incidents (adverse events) after vaccination is required. For the 2019/2020 season, we monitored the adverse events reported by a representative sample of people in Belgium, Germany, and Spain within 7 days after receiving GSK's seasonal influenza vaccine.

Of the 1082 people who received the first dose of the vaccine, 39% reported at least one adverse event, such as pain and swelling at the injection site, tiredness, fever, headache, or dizziness. A total of 115 children under 9 years of age received two doses 4 weeks apart. After their second dose, few of these children (8%) reported adverse events. The most frequent adverse events were fever, swelling and pain at the injection site, runny nose, or irritability. No serious adverse events were reported after either the first or second dose.

No serious adverse events related to GSK’s seasonal influenza vaccine within the 7 days after vaccination were reported. This study supports the favourable risk–benefit safety profile of GSK's seasonal influenza vaccine.

Sex Differences in Adverse Reactions to an Inactivated SARS-CoV-2 Vaccine Among Medical Staff in China

Objective: We investigated whether there were sex differences in adverse reactions to an inactivated SARS-CoV-2 vaccine among medical staff in China. Methods: From 24 February to 7 March 2021 an online cross-sectional survey was conducted with a self-administered COVID-19 vaccine questionnaire among medical staff in Taizhou, China. In total, 1397 interviewees (1,107 women and 290 men) participated in the survey. Results: In our study, 178 (16.1%) women and 23 (7.9%) men reported adverse reactions following their first vaccination, and 169 (15.3%) women and 35 (12.1%) men reported adverse reactions following their second vaccination. After adjusting for confounding factors, adverse reactions to other vaccines, worry about adverse reactions, knowledge of the inactivated vaccine being used in the hospital, taking the vaccine for one's family proactively and receiving an influenza vaccination were significantly related to adverse reactions to both injections in women. In contrast, in men, concerns about adverse reactions independently increased the risk of adverse reactions following either vaccination, and a history of adverse reactions to other vaccines also increased the risk of adverse reactions to both injections. Conclusions: Sex differences in the frequency of reported adverse reactions to an inactivated SARS-CoV-2 vaccine and potential factors were demonstrated in a sample of medical staff.

Safety of SARS-CoV-2 vaccines: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Various modalities of vaccines against coronavirus disease 2019 (COVID-19), based on different platforms and immunization procedures, have been successively approved for marketing worldwide. A comprehensive review for clinical trials assessing the safety of COVID-19 vaccines is urgently needed to make an accurate judgment for mass vaccination.

MAIN TEXT

A systematic review and meta-analysis was conducted to determine the safety of COVID-19 vaccine candidates in randomized controlled trials (RCTs). Data search was performed in PubMed, Embase, Cochrane library, Scopus, Web of Science, and MedRxiv. Included articles were limited to RCTs on COVID-19 vaccines. A total of 73,633 subjects from 14 articles were included to compare the risks of adverse events following immunization (AEFI) after vaccinating different COVID-19 vaccines. Pooled risk ratios (RR) of total AEFI for inactivated vaccine, viral-vectored vaccine, and mRNA vaccine were 1.34 [95% confidence interval (CI) 1.11-1.61, P < 0.001], 1.65 (95% CI 1.31-2.07, P < 0.001), and 2.01 (95% CI 1.78-2.26, P < 0.001), respectively. No significant differences on local and systemic AEFI were found between the first dose and second dose. In addition, people aged ≤ 55 years were at significantly higher risk of AEFI than people aged ≥ 56 years, with a pooled RR of 1.25 (95% CI 1.15-1.35, P < 0.001).

CONCLUSIONS

The safety and tolerance of current COVID-19 vaccine candidates are acceptable for mass vaccination, with inactivated COVID-19 vaccines candidates having the lowest reported AEFI. Long-term surveillance of vaccine safety is required, especially among elderly people with underlying medical conditions.

Safety of SARS-CoV-2 vaccines: a systematic review and meta-analysis of randomized controlled trials

Background

Various modalities of vaccines against coronavirus disease 2019 (COVID-19), based on different platforms and immunization procedures, have been successively approved for marketing worldwide. A comprehensive review for clinical trials assessing the safety of COVID-19 vaccines is urgently needed to make an accurate judgment for mass vaccination.

Main text

A systematic review and meta-analysis was conducted to determine the safety of COVID-19 vaccine candidates in randomized controlled trials (RCTs). Data search was performed in PubMed, Embase, Cochrane library, Scopus, Web of Science, and MedRxiv. Included articles were limited to RCTs on COVID-19 vaccines. A total of 73,633 subjects from 14 articles were included to compare the risks of adverse events following immunization (AEFI) after vaccinating different COVID-19 vaccines. Pooled risk ratios (RR) of total AEFI for inactivated vaccine, viral-vectored vaccine, and mRNA vaccine were 1.34 [95% confidence interval (CI) 1.11–1.61, P < 0.001], 1.65 (95% CI 1.31–2.07, P < 0.001), and 2.01 (95% CI 1.78–2.26, P < 0.001), respectively. No significant differences on local and systemic AEFI were found between the first dose and second dose. In addition, people aged ≤ 55 years were at significantly higher risk of AEFI than people aged ≥ 56 years, with a pooled RR of 1.25 (95% CI 1.15–1.35, P < 0.001).

Conclusions

The safety and tolerance of current COVID-19 vaccine candidates are acceptable for mass vaccination, with inactivated COVID-19 vaccines candidates having the lowest reported AEFI. Long-term surveillance of vaccine safety is required, especially among elderly people with underlying medical conditions.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-021-00878-5.

Post-Marketing Active Surveillance of Adverse Reactions Following Influenza Cell-Based Quadrivalent Vaccine: An Italian Prospective Observational Study

Since the influenza season 2018/19, the Italian Ministry of Health recommended a dose of cell-based quadrivalent vaccine (Flucelvax Tetra) for HCWs (healthcare workers), because this vaccine seemed more efficacious in the prevention of AH3N2 virus. Due to the lack of pre-registration data, the safety profile of this new vaccine must be investigated in post-marketing surveillance. The aim of our study is to evaluate, through a post-marketing active surveillance program developed during the 2019/20 influenza season, any Adverse Events Following Immunization (AEFIs) that happened in the 7 days after immunization with Flucelvax Tetra. The study was carried out in a sample of HCWs of Policlinico General University-Hospital (Apulia, South Italy). AEFIs were classified as ‘serious’ or ‘not serious’ according to the WHO (World Health Organization) guidelines; the WHO causality assessment algorithm was applied to classify serious AEFIs. A total of 741 HCWs were enrolled, and 430 AEFIs (reporting rate: 58.0 (95%CI: 54.4–61.6) × 100 enrolled) were recorded. Of these, 429 of 430 (99.8%; reporting rate: 57.8 (95%CI: 54.2–61.5) × 100 enrolled) were classified as not serious and one (0.2%; reporting rate: 0.13 (0.03–0.75) × 100 enrolled) was classified as serious. Local reactions were the adverse reaction reported most frequently (88%); regarding the serious AEFI, causality assessment excluded the causal link with the administration of the vaccine. All the AEFIs resolved without sequelae. Flucelvax Tetra showed a profile of high safety. Due to their characteristics of greater sensitivity than passive surveillance, active surveillance programs can be useful in defining the safety profiles of a given vaccine/drug in certain population subgroups.

Brand-Specific Enhanced Safety Surveillance of GSK's Quadrivalent Seasonal Influenza Vaccine in Belgium, Germany and Spain for the 2018/2019 Season

Introduction

Seasonal influenza causes numerous deaths worldwide each year. Annual vaccination for disease prevention is crucial. Seasonal vaccines are updated each year to closely match circulating strains.

Objective

To comply with European Medicines Agency (EMA) guidance, an enhanced safety study was conducted to rapidly collect and assess adverse events (AEs) within 7 days following vaccination with GSK’s inactivated quadrivalent seasonal influenza vaccine (IIV4) in 2018/2019.

Methods

A customised AE reporting card (AERC) and standardised electronic data reporting application were used in Belgium, Germany and Spain in adult and paediatric subjects in this study.

Results

In 2018, 1060 subjects vaccinated with one dose of GSK’s IIV4 were enrolled (all subjects in Belgium and Germany were adults, and 75% and 25% of subjects in Spain were children and adults, respectively). In Spain, 139 eligible children later received a second dose. Overall 1035 subjects completed the study. After dose 1 and dose 2, 98.3% and 100% of subjects, respectively, returned the completed AERC. Over the study period, 43.0% (456/1060 post dose 1) and 23.7% (33/139 post dose 2) of subjects reported at least one AE within 7 days after immunisation. The most frequently reported categories of AEs were General and Administration Site (e.g. injection site pain, swelling, erythema) and Respiratory Disorders (e.g. rhinorrhoea, cough, nasal congestion). There were no deaths and no serious AEs deemed related to GSK’s IIV4.

Conclusion

In compliance with EMA guidance, this study design allowed for near real-time assessment of AEs. No safety signals were detected at any point during the study period. The study supports and confirms the acceptable safety profile of GSK’s IIV4.

ClinicalTrials.gov identifier

NCT03688620.

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

IMPORTANCE

Every year, influenza vaccines are administered to millions of people worldwide to reduce morbidity and mortality from influenza. As new vaccine formulations are increasingly used, monitoring and comparing safety, in addition to vaccine effectiveness, in target populations are essential.

OBJECTIVE

To assess the postmarketing safety profile of 2018 Southern Hemisphere influenza vaccines, particularly 2 new enhanced trivalent inactivated influenza vaccines: an adjuvanted trivalent inactivated influenza vaccine (aIIV3) and high-dose trivalent inactivated influenza vaccine (HD-IIV3), among Australian individuals 65 years or older.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used solicited short message service-based self-reported survey data on adverse events occurring within 3 to 5 days after receipt of an influenza vaccination. Participants included individuals 65 years or older who received routinely recommended influenza vaccines at 1 of 265 sentinel immunization sites, including primary care, hospital, and community-based clinics, participating in Australia's AusVaxSafety active vaccine safety surveillance system from April 1 to August 31, 2018. Data were analyzed from September 1, 2018, to June 30, 2019.

EXPOSURE

Any licensed 2018 influenza vaccine administered in clinical practice.

MAIN OUTCOMES AND MEASURES

Rates (overall, by brand, and by concomitant vaccine receipt) of adverse events, including medical attendance as a proxy for serious adverse events.

RESULTS

Of 72 013 individuals 65 years or older who received an influenza vaccine in 2018, 50 134 individuals (69.6%) responded to the initial survey regarding adverse events experienced after vaccination (median [interquartile range] age, 71 [68-76] years; 27 056 [54.0%] women). Most individuals received an enhanced trivalent inactivated influenza vaccine, including 28 003 individuals (55.9%) who received aIIV3 and 19 306 individuals (38.5%) who received HD-IIV3; 2208 individuals (4.4%) received a quadrivalent inactivated influenza vaccine. Individuals who received HD-IIV3 reported significantly higher rates of any adverse event compared with individuals who received aIIV3 (1716 individuals [8.9%] vs 1796 individuals [6.4%]; P < .001) as well as specific adverse events, including fever (195 individuals [1.1%] vs 164 individuals [0.6%]; P < .001), injection site pain (383 individuals [2.1%] vs 350 individuals [1.3%]; P < .001), and injection site swelling or redness (256 individuals [1.4%] vs 248 individuals [0.9%]; P < .001). Adverse event rates reported by those receiving any quadrivalent inactivated influenza vaccine were similar to rates reported by those receiving aIIV3. Rates of medical care seeking for adverse events associated with aIIV3 and HD-IIV3 were low and comparable (80 individuals [0.3%] vs 56 individuals [0.3%]; P = .91).

CONCLUSIONS AND RELEVANCE

The findings of this large-scale participant-based postmarketing assessment of the safety of 2 new enhanced influenza vaccines used in individuals 65 years or older provide reassuring near-real-time and cumulative data to inform and support confidence in ongoing vaccine use.

Enhanced Safety Surveillance of GSK's Quadrivalent Seasonal Influenza Vaccine in Belgium, Germany, and Spain for the 2018/19 Season: Interim Analysis

INTRODUCTION

Influenza is an important cause of morbidity and mortality in Europe. Prevention by annual vaccination is most effective but with yearly vaccine reformulation to match circulating virus strains, vaccine safety must be continuously monitored. The European Medicines Agency published guidance on safety monitoring of influenza vaccines.

METHODS

An enhanced safety surveillance study of GSK's inactivated quadrivalent influenza vaccine (IIV4) was conducted in Belgium, Germany, and Spain in influenza season 2018/19. The objective was to collect adverse event (AE) reports from subjects within 7 days of vaccination. A customized AE reporting card (AERC) with predefined AEs of interest was used to rapidly detect and evaluate potential new safety concerns. Interim results are presented here.

RESULTS

Between week 40 and 52, 1060 vaccinated subjects were enrolled (31.0% Belgium, 26.2% Germany, and 42.7% Spain) covering all ages for which IIV4 is indicated (32.0% aged 6 months-17 years, 33.8% 18-65 years, and 34.2% over 65 years). Pediatric subjects  less than 9 years old (n = 139) received two doses. Following dose 1 and dose 2, 98.2% and 100%, respectively, returned the completed AERC recording any AEs. Following dose 1 and dose 2, 454 and 34 subjects, respectively, reported at least one AE (most frequently expected general and injection site symptoms and respiratory symptoms).

CONCLUSION

All reported AEs were expected as per summary product characteristics (smPC). No safety signals that impact public health or alter the benefit-risk profile of GSK's IIV4 were identified. Subjects from all vaccinated age groups were enrolled and the use of AERCs allowed rapid monitoring and analysis of reported AEs.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03688620.

FUNDING

GlaxoSmithKline Biologicals SA.

Challenges in implementing yearly enhanced safety surveillance of influenza vaccination in Europe: lessons learned and future perspectives

Seasonal influenza vaccines are frequently reformulated, leading to specific challenges for continuous benefit/risk monitoring. In 2014, the European Medicines Agency started requiring annual enhanced safety surveillance (ESS). This article provides a perspective on ESS studies conducted ever since and aims to map existing initiatives used to monitor adverse events following influenza immunization. Of 11 ESS studies, reporting surveillance data of at least five different vaccine brands during four seasons, all were able to rapidly capture vaccine-specific adverse events of interest reports. However, challenges have been identified during study implementation, including recruitment of sufficient participants, enrolling younger age groups, collecting data of vaccine batch numbers, comparing observed with expected rates and achieving adequate return of reported events. Harmonizing safety monitoring standards across countries, and bridging between routine pharmacovigilance and ESS, is likely to allow more comprehensive assessments of influenza vaccine safety, requiring close collaboration between regulators, public health, and manufacturers.