Rapid online identification of adverse events after influenza immunization in children by PCIRN's National Ambulatory Network

mRNA COVID-19 vaccine safety among older adults from the Canadian National Vaccine Safety Network

This study examined short-to-medium term safety of COVID-19 vaccines among adults aged ≥65 years using the Canadian National Vaccine Safety Network active safety surveillance data. Both vaccinated and unvaccinated older adult participants recruited from seven provinces and territories were included in the analysis. Safety was assessed at 7 days after COVID-19 vaccination (dose 1, 2 and 3), and 7 months after dose 1. Multivariable logistic regression was used to examine the association between BNT162b2/mRNA-1273 COVID-19 vaccines and two short-term health events: 1) health event preventing daily activities and/or required medical consultation, 2) serious health events resulting in an emergency department visit and/or hospitalization within 7 days following each dose. We also assessed the rates of serious health events for the period between dose 1 and 2, and 7-months following dose 1. Between December 2020 and February 2022, a total of 173,038, 104,452, and 13,970 older adults completed dose 1, dose 2, and dose 3 surveys, respectively. The control survey was completed by 2,955 unvaccinated older adults. Health events occurred more frequently among recipients after dose 2 homologous mRNA-1273 (adjusted odds ratio [95 % confidence interval]: 2.91 [2.24-3.79]) and dose two heterologous (BNT162b2 followed by mRNA-1273): 1.50 [1.12-2.02] compared to unvaccinated counterparts. There was no difference in event rates after any dose of BNT162b2 and unvaccinated participants. The rates of serious health events following COVID-19 vaccination were very low (≤0.3 %) across all vaccine products and doses, and were not higher compared to unvaccinated controls, and were not associated with an emergency department visit or hospitalization within 7 days following vaccination. Reported symptoms were self-limited and rarely required medical assessment. Our findings further strengthen the current evidence that mRNA COVID-19 vaccines are safe and can be used to inform older adults about expected adverse events following COVID-19 vaccination.

Active surveillance of immunization adverse effects: a multicentre, open-label, three-arm randomized uncontrolled trial in Ethiopia

BACKGROUND

Participant-centred active adverse event following immunization (AEFI) surveillance can offer real-time vaccine safety data and help in signal detection. This study aimed to evaluate the effectiveness of participant-centred active adverse events (AEs) surveillance following measles immunization in Gedeo Zone health facilities in Ethiopia.

METHODS

An open-label, multicentred, three-arm randomized uncontrolled trial was conducted from 1 June to 21 October 2023. After assessing enrolment eligibility, the study participants were randomized into three groups (short message service [SMS], telephone interview, and diary card). They were expected to report AEs in children 1 week after receiving immunization. Binary and multivariable logistic regression and χ2 tests were used to analyse the data.

RESULTS

Among the 396 participants randomized into the three groups, 80.8% (320 participants) reported back about their children's AE status. Participants in the telephone interview group exhibited a substantially superior response rate (93.2% of 132 participants; p<0.00001) compared with the SMS (71.2%) and diary card (78%) groups. The likelihood of reporting the status of AEs experienced by children was lower by 77% (adjusted odds ratio 0.23 [95% confidence interval 0.1 to 0.52], p-value <0.00001) in the diary card group compared with the telephone interview group.

CONCLUSIONS

In this study, a telephone interview was found to be the best method for AEFI reporting. Participant-centred active AE surveillance could potentially permit more rapid identification of emerging safety signals. Trial registration:  https://clinicaltrials.gov/ct2/show/NCT05803538.

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.

Comparing the Use of a Mobile App for Surveillance of Adverse Events Following Influenza Immunization to a Web-Based platform: a Randomized Controlled Trial (Preprint)

BACKGROUND

Vaccine safety surveillance is a core component of vaccine pharmacovigilance. In Canada, active, participant-centered vaccine surveillance is available for influenza vaccines and has been used for COVID-19 vaccines.

OBJECTIVE

The objective of this study is to evaluate the effectiveness and feasibility of using a mobile app for reporting participant-centered seasonal influenza adverse events following immunization (AEFIs) compared to a web-based notification system.

METHODS

Participants were randomized to influenza vaccine safety reporting via a mobile app or a web-based notification platform. All participants were invited to complete a user experience survey.

RESULTS

Among the 2408 randomized participants, 1319 (54%) completed their safety survey 1 week after vaccination, with a higher completion rate among the web-based notification platform users (767/1196, 64%) than among mobile app users (552/1212, 45%; P<.001). Ease-of-use ratings were high for the web-based notification platform users (99% strongly agree or agree) and 88.8% of them strongly agreed or agreed that the system made reporting AEFIs easier. Web-based notification platform users supported the statement that a web-based notification-only approach would make it easier for public health professionals to detect vaccine safety signals (91.4%, agreed or strongly agreed).

CONCLUSIONS

Participants in this study were significantly more likely to respond to a web-based safety survey rather than within a mobile app. These results suggest that mobile apps present an additional barrier for use compared to the web-based notification-only approach.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05794113; https://clinicaltrials.gov/show/NCT05794113.

2017/18 and 2018/19 seasonal influenza vaccine safety surveillance, Canadian National Vaccine Safety (CANVAS) Network

Background

The Canadian National Vaccine Safety (CANVAS) network monitors the safety of seasonal influenza vaccines in Canada.

Aim

To provide enhanced surveillance for seasonal influenza and pandemic influenza vaccines.

Methods

In 2017/18 and 2018/19 influenza seasons, adults (≥ 15 years of age) and parents of children vaccinated with the seasonal influenza vaccine participated in an observational study using web-based active surveillance. Participants completed an online survey for health events occurring in the first 7 days after vaccination. Participants who received the influenza vaccine in the previous season, but had not yet been vaccinated for the current season, were unvaccinated controls.

Results

In 2017/18, 43,751 participants and in 2018/19, 47,798 completed the online safety survey. In total, 957 of 30,173 participants vaccinated in 2017/18 (3.2%; 95% confidence interval (CI): 3.0–3.4) and 857 of 25,799 participants vaccinated in 2018/19 (3.3%; 95% CI: 3.1–3.5) reported a health problem of sufficient intensity to prevent their normal daily activities and/or cause them to seek medical care (including hospitalisation). This compared to 323 of 13,578 (2.4%; 95% CI: 2.1–2.6) and 544 of 21,999 (2.5%; 95% CI: 2.3–2.7) controls in each respective season. The event rate in vaccinated adults and children was higher than the background rate and was associated with specific influenza vaccines. The higher rate of events was associated with systemic symptoms and migraines/headaches.

Conclusion

In 2017/18 and 2018/19, higher rates of events were reported following seasonal influenza vaccination than in the pre-vaccination period. This signal was associated with several seasonal influenza vaccine products.

Investigating the association of receipt of seasonal influenza vaccine with occurrence of anesthesia/paresthesia and severe headaches, Canada 2012/13-2016/17, the Canadian Vaccine Safety Network

BACKGROUND

Concern about adverse events following immunization is frequently cited by both those who receive or decline vaccines. Neurological adverse events are especially concerning.

OBJECTIVES

Our aim was to detect associations between seasonal influenza vaccination and the occurrence of severe anesthesia/paresthesia or severe headaches.

METHODS

Data were analyzed from the Canadian National Vaccine Safety network. Events occuring on days 0-7 were self-reported and prevented daily activity, led to school or work absenteeism, or required medical attention. Controls were the previous year's vaccinees; events in controls were collected prior to the start of the influenza vaccination program of each year (2012/13 through 2016/17). Multivariable logistic regression was used to determine the association between seasonal influenza vaccination and the occurrence of anesthesia/paresthesia or severe headaches.

RESULTS

The total sample was 107,565 for investigating anesthesia/paresthesia and 97,420 for investigating severe headaches. Anesthesia/paresthesia was reported by 104/107,565 (0.10%) participants; 63/69,129 (0.09%) vaccinees and 41/38,436 (0.11%) controls (adjusted odds ratio (aOR) = 0.89; 95% CI = 0.60, 1.32). Severe headaches were reported by 1361/97,420 (1.40%) participants; 907/61,463 (1.48%) vaccinees and 454/35,957 (1.26%) controls (aOR = 1.21; 95% CI = 1.08, 1.36). No specific vaccine product was associated with severe headaches.

CONCLUSIONS

Our study found no association between severe anesthesia/paresthesia and seasonal influenza vaccination. While there was an association with severe headaches as an adverse event following influenza vaccination, the rates of these events are similar to rates reported from clinical trials and are not a cause for additional concern.

Enhanced Safety Surveillance of Seasonal Quadrivalent Influenza Vaccines in English Primary Care: Interim Analysis

INTRODUCTION

The European Medicines Agency (EMA) requires vaccine manufacturers to conduct enhanced safety surveillance (ESS) of seasonal influenza vaccines including a near real-time evaluation of collected data. The objective was to identify whether the use of passive surveillance or active surveillance provides different results of reported adverse events of interest (AEIs) by specified age strata and AEI type. We report the weekly incidence rates of AEIs within 7 days following seasonal influenza vaccination using passive and active surveillance.

METHODS

AEIs were collected within 7 days of vaccination from ten general practices predominantly administering inactivated quadrivalent influenza vaccine (IIV4, Fluarix Tetra, GSK). Vaccinees completed an adverse drug reaction (ADR) card. ADR card and medically attended AEIs data were recorded in practice electronic health records. We report the outcome of the first 5 weeks of safety surveillance (September 12, 2016-October 16, 2016); in an exploratory analysis, rates of AEI for IIV4 are compared to those passively reported through a sentinel network.

RESULTS

Practices vaccinated 13.1% (12,864/98,091) of their registered population; 5.6% (95% CI 5.20-6.00) of them reported AEIs, none serious. The most frequent were respiratory 2.60% (95% CI 2.33-2.88), musculoskeletal 1.82% (95% CI 1.59-2.05) and neurological 1.05% (95% CI 0.88-1.23). AEIs were more frequently reported for adults than for children; 5.91% (95% CI 5.49-6.34) compared to 1.49% (95% CI 0.69-2.29); 47.18% of the adults reported AEI using the ADR card, none were returned for subjects < 18 years old. The frequency of AEIs reporting was higher, 6.88% (95% CI 6.35-7.42) vs. 3.30% (95% CI 2.68-3.96, 100/3028, p < 0.000), through ESS than passive surveillance.

CONCLUSION

The ESS did not reveal any safety signal and we demonstrated the feasibility of conducting ESS following EMA recommendations. The use of a customised ADR card led to a doubling of AEIs reports over passive surveillance in adults.

FUNDING

GlaxoSmithKline Biologicals SA, Wavre, Belgium.

Participant-centred active surveillance of adverse events following immunisation: a narrative review

The importance of active, participant-centred monitoring of adverse events following immunisation (AEFI) is increasingly recognised as a valuable adjunct to traditional passive AEFI surveillance. The databases OVID Medline and OVID Embase were searched to identify all published articles referring to AEFI. Only studies which sought participant response after vaccination were included. A total of 6060 articles published since the year 2000 were identified. After the application of screening inclusion and exclusion criteria, 25 articles describing 23 post-marketing AEFI systems were identified. Most countries had a single system: Ghana, Japan, China, Korea, Netherlands, Singapore, Brazil, Cambodia, Sri Lanka, Turkey and Cameroon except the USA (2), Canada (4) and Australia (6). Data were collected from participants with and without AEFI in all studies reviewed with denominator data enabling AEFI rate calculations. All studies considered either a single vaccine or specified vaccines or were time limited except one Australian system, which provides continuous automated participant-centred active surveillance of all vaccines. Post-marketing surveillance systems using solicited patient feedback are emerging as a novel AEFI monitoring tool. A number of exploratory systems utilising e-technology have been developed and their potential for scaling up and application in low and middle income countries deserves further investigation.

Rapid surveillance for health events following a mass meningococcal B vaccine program in a university setting: A Canadian Immunization Research Network study

An outbreak of Neisseria meningitidis serotype B infection occurred at a small residential university; public health announced an organizational vaccination program with the 4-component Meningococcal B (4CMenB) vaccine (Bexsero(TM), Novartis/GlaxoSmithKline Inc.) several days later. Since there were limited published data on reactogenicity of 4CMenB in persons over 17years of age, this study sought to conduct rapid surveillance of health events in vaccinees and controls using an online survey. Vaccine uptake was 84.7% for dose 1 (2967/3500) and 70% (2456/3500) for dose 2; the survey response rates were 33.0% (987/2967) and 18.7% (459/2456) in dose 1 and dose 1 recipients respectively, and 12% in unvaccinated individuals (63/533). Most students were 20-29years of age (vaccinees, 64.0%; controls, 74.0). A new health problem or worsening of an existing health problem was reported by 30.0% and 30.3% of vaccine recipients after doses 1 and 2 respectively; and by 15.9% of controls. These health problems interfered with the ability to perform normal activities in most vaccinees reporting these events (74.7% post dose 1; 62.6% post dose 2), and in 60% of controls. The health problems led to a health care provider visit (including emergency room) in 12.8% and 14.4% of vaccinees post doses 1 and 2, respectively and in 40% of controls. The most common reactions in vaccinees were injection site reactions (20.6% post dose 1, 16.1% post dose 20 and non-specific systemic complaints (22.6% post dose 1, 17.6% post dose 2). No hospitalizations were reported. An online surveillance program during an emergency meningococcal B vaccine program was successfully implemented, and detected higher rates of health events in vaccinees compared to controls, and high rates of both vaccinees and controls seeking medical attention. The types of adverse events reported by young adult vaccinees were consistent with those previously.

An evaluation of the feasibility and usability of a proof of concept mobile app for adverse event reporting post influenza vaccination

The Canadian National Vaccine Safety network (CANVAS) gathers and analyzes safety data on individuals receiving the influenza vaccine during the early stages of annual influenza vaccination campaigns with data collected via participant surveys through the Internet. We sought to examine whether it was feasible to use a mobile application (app) to facilitate AEFI reporting for the CANVAS network. To explore this, we developed a novel smartphone app, recruited participants from a hospital influenza immunization clinic and by word of mouth and instructed them to download and utilize the app. The app reminded participants to complete the CANVAS AEFI surveillance surveys ("AEFI surveys") on day 8 and 30, a survey capturing app usability metrics at day 30 ("usability survey") and provided a mechanism to report AEFI events spontaneously throughout the whole study period. All survey results and spontaneous reports were recorded on a privacy compliant, cloud server. A software plug-in, Lookback, was used to record the on-screen experience of the app sessions. Of the 76 participants who consented to participate, 48(63%) successfully downloaded the app and created a profile. In total, 38 unique participants completed all of the required surveillance surveys; transmitting 1104 data points (survey question responses and spontaneous reports) from 83 completed surveys, including 21 usability surveys and one spontaneous report. In total, we received information on new or worsening health conditions after receiving the influenza vaccine from 11(28%) participants. Of the usability survey responses, 86% agreed or strongly agreed that they would prefer to use a mobile app based reporting system instead of a web-based system. The single spontaneous report received was from a participant who had also reported using the Day 8 survey. Of Lookback observable sessions, an accurate transmission proportion of 100% (n=290) was reported for data points. We demonstrated that a mobile app can be used for AEFI reporting, although download and survey completion proportions suggest potential barriers to adoption. Future studies should examine implementation of mobile reporting in a broader audience and impact on the quality of reporting of adverse events following immunization.

Canadian vaccine research networks: Vaccine safety resources for Canada

The Public Health Agency of Canada / Canadian Institutes of Health Research Influenza Research Network (PCIRN), established in 2009 to undertake evaluative research to inform public health decision making in Canada, is now being replaced by the Canadian Immunization Research Network (CIRN), which will retain the mandate of PCIRN but expand it to all vaccines including influenza vaccine. CIRN is organized as a network of networks focusing on undertaking research in the areas of vaccine safety, adverse events following immunization (AEFIs), vaccine hesitancy, vaccine effectiveness, and vaccine coverage. CIRN's networks include: a clinical trial network; a laboratory network; a modelling and economics network; a network of social science and humanities researchers; a vaccine safety surveillance network; a hospital-based surveillance network; a clinic network to evaluate serious AEFIs; and a network that links vaccine research capacity in provincial health agencies and departments. PCIRN has contributed to Canada's vaccine safety surveillance system and has facilitated the translation of safety research into policy. Vaccine safety surveillance and research will remain a focus of the newly formed Canadian Immunization Research Network.