Adverse events following immunisation (AEFI) reports from the Zimbabwe expanded programme on immunisation (ZEPI): an analysis of spontaneous reports in Vigibase® from 1997 to 2017

Data-Driven Identification of Factors That Influence the Quality of Adverse Event Reports: 15-Year Interpretable Machine Learning and Time-Series Analyses of VigiBase and QUEST

BACKGROUND

The completeness of adverse event (AE) reports, crucial for assessing putative causal relationships, is measured using the vigiGrade completeness score in VigiBase, the World Health Organization global database of reported potential AEs. Malaysian reports have surpassed the global average score (approximately 0.44), achieving a 5-year average of 0.79 (SD 0.23) as of 2019 and approaching the benchmark for well-documented reports (0.80). However, the contributing factors to this relatively high report completeness score remain unexplored.

OBJECTIVE

This study aims to explore the main drivers influencing the completeness of Malaysian AE reports in VigiBase over a 15-year period using vigiGrade. A secondary objective was to understand the strategic measures taken by the Malaysian authorities leading to enhanced report completeness across different time frames.

METHODS

We analyzed 132,738 Malaysian reports (2005-2019) recorded in VigiBase up to February 2021 split into historical International Drug Information System (INTDIS; n=63,943, 48.17% in 2005-2016) and newer E2B (n=68,795, 51.83% in 2015-2019) format subsets. For machine learning analyses, we performed a 2-stage feature selection followed by a random forest classifier to identify the top features predicting well-documented reports. We subsequently applied tree Shapley additive explanations to examine the magnitude, prevalence, and direction of feature effects. In addition, we conducted time-series analyses to evaluate chronological trends and potential influences of key interventions on reporting quality.

RESULTS

Among the analyzed reports, 42.84% (56,877/132,738) were well documented, with an increase of 65.37% (53,929/82,497) since 2015. Over two-thirds (46,186/68,795, 67.14%) of the Malaysian E2B reports were well documented compared to INTDIS reports at 16.72% (10,691/63,943). For INTDIS reports, higher pharmacovigilance center staffing was the primary feature positively associated with being well documented. In recent E2B reports, the top positive features included reaction abated upon drug dechallenge, reaction onset or drug use duration of <1 week, dosing interval of <1 day, reports from public specialist hospitals, reports by pharmacists, and reaction duration between 1 and 6 days. In contrast, reports from product registration holders and other health care professionals and reactions involving product substitution issues negatively affected the quality of E2B reports. Multifaceted strategies and interventions comprising policy changes, continuity of education, and human resource development laid the groundwork for AE reporting in Malaysia, whereas advancements in technological infrastructure, pharmacovigilance databases, and reporting tools concurred with increases in both the quantity and quality of AE reports.

CONCLUSIONS

Through interpretable machine learning and time-series analyses, this study identified key features that positively or negatively influence the completeness of Malaysian AE reports and unveiled how Malaysia has developed its pharmacovigilance capacity via multifaceted strategies and interventions. These findings will guide future work in enhancing pharmacovigilance and public health.

Efficacy and feasibility of SMS m-Health for the detection of adverse events following immunisation (AEFIs) in resource-limited setting-The Zimbabwe stimulated telephone assisted rapid safety surveillance (Zm-STARSS) randomised control trial

INTRODUCTION

The mHealth active participant centred (MAPC) adverse events following immunisation (AEFI) surveillance is a promising area for early AEFI detection resulting in risk minimisation. Passive (spontaneous) AEFI surveillance is the backbone for vaccine pharmacovigilance, but has inherent drawbacks of under reporting, and requires strengthening with active surveillance methods.

AIM

The Zimbabwe stimulated telephone assisted rapid safety surveillance (Zm-STARSS) randomised controlled trial (RCT) sought to evaluate the efficacy and feasibility of AEFI detection using a short message service (SMS) and computer assisted telephone interview (CATI) approach.

METHOD

A multicentre Zm-STARSS RCT enrolled consented adult vaccinees or parents or guardians of children receiving vaccines, including COVID-19 vaccines, at study vaccination clinics. At enrolment study participants were randomised to either SMS-CATI group or control group. SMS prompts were sent on days 0-2 and 14 post-vaccination to SMS-CATI group to ascertain if a medically attendance or attention due to an Adverse event following immunisation (AEFI) had occurred. However, no SMSs were sent to the control group. SMS-CATI group who responded "Yes" to SMS prompts were interviewed by research healthcare workers (RHCWs) who completed a CATI to determine if an AEFI had occurred whilst an AEFI in control group was determined from passive AEFI reporting channels. The primary study outcome was the AEFI detection rate in the SMS-CATI group compared to the control group.

RESULTS

A total of 4560 participants were enrolled after signed informed consent, all were encouraged to report AEFIs and randomised automatically on 1:1 basis into two arms SMS CATI intervention group (n = 2280) and a control passive AEFI surveillance group (n = 2280) on day 0. A total of 704 (31 %) participants responded to the SMS prompts, with 75 % (528/704) indicating "No" and 25 % (176/704) reporting "Yes" to seeking medical attention or attendance post-immunisation. 69 % (121/176) completed a CATI survey but in only 36 % (44/121) was the AEFI confirmed. There were no AEFIs reported in control group participants. The detection rate of a AEFI associated with medically attendance or attention using the SMS-CATI methodology was 2 % (44/2280) on an intention to treat cohort.

CONCLUSION

Despite the low SMS response and CATI completion rate, we demonstrated that Zm-STARSS SMS system improves AEFI detection compared to passive AEFI surveillance. We recommend that this and similar approaches are explored further using cost-effective multi-channel digital approaches for holistic pharmacovigilance to improve AEFI detection in Low Middle-Income Countries (LMICs) for all vaccines.

Barriers to optimal AEFI surveillance and documentation in Nigeria: Findings from a qualitative survey

Effective spontaneous AEFI reporting is the first step to ensuring vaccine safety. Half of the global population lives in countries with weak vaccine safety monitoring systems, especially in the African, Eastern Mediterranean, and Western Pacific regions. Further, Immunisation services have been upscaled without commensurate effective AEFI surveillance systems. Hence, this study aims to comprehensively investigate the impediments to an effective AEFI surveillance system. Given the programmatic and regulatory implications, understanding these impediments would facilitate the development and implementation of policies and strategies to strengthen the AEFI surveillance system in Nigeria. A qualitative research design (using a grounded theory approach) was employed by conducting ten key informant interviews and two Focus Group Discussion sessions among the study population to identify the barriers impeding optimal AEFI surveillance and documentation in Nigeria. This study found that the AEFI surveillance system is in place in Nigeria. However, its functionality is sub-optimal, and the potential capacity is yet to be fully harnessed due to health systems and socio-ecological impediments. The identified impediments are human-resource-related issues- knowledge gaps; limited training; lack of designated officers for AEFI; excessive workload; poor supportive supervision and attitudinal issues; caregiver's factor; governance and leadership- moribund AEFI committee; lack of quality supervisory visit and oversight and weak implementation of AEFI policy guidance. Others include funding and logistics issues- no dedicated budget provision and weak referral mechanism; insecurity; socio-economic and infrastructural deficits- poverty, geographical barriers, limited ICT skills, and infrastructure; and poor feedback and weak community engagement by the health workers. Findings from this study provide empirical evidence and serve as an advocacy tool for vaccine pharmacovigilance strengthening in Nigeria. Addressing the impediments requires health system strengthening and a whole-of-the-society approach to improve vaccine safety surveillance, restore public confidence and promote vaccine demand, strengthen PHC services, and contribute to attaining UHC and SDGs.

Evaluation of vaccination status of children with special health care needs in Suzhou, China, 2020-2022: A retrospective survey study

Children with special health care needs (CSHCNs) are at an increased risk of vaccine-preventable infections (VPDs), but they also face the dilemma of vaccine hesitancy. We obtained information on pediatric visits from the Referral and Assessment Information System for Vaccination (RAISV) and information on vaccination from the Jiangsu Province Immunization Information System (JSIIS). We followed the occurrence of Adverse Events Following Immunization (AEFIs) and VPDs by actively calling and querying the China Information System for Disease Control and Prevention (CISDCP). The Poisson test was used to compare the incidence of AEFIs between groups. A total of 5,037 children who visited a vaccination assessment clinic were followed-up in this study. The majority were children with developmental anomalies (28.5%), certain conditions originating in the perinatal period (12.1%), and nervous system disorders (9.0%). Most CSHCNs (66.9%) were advised to have all vaccines according to routine practice, 29.0% were advised to have partial vaccination, and 4.1% were advised to delay all vaccines and wait for future assessment. A total of 201 (4.0%) CSHCNs were not vaccinated, although they were assessed to be eligible for vaccination. By querying the immunization planning module in CISDCP, we observed 55 AEFI cases, which amounted to an incidence rate of 1.2 per 1,000, and the occurrence of abnormal reactions was not significantly different compared with the general population. The vaccination program following the designed workflow for CSHCNs was safe and could be recommended in other areas.

Completeness of pharmaceutical industry insulin adverse event reports from Africa and the Middle East

BACKGROUND

Growing numbers of patients with diabetes mellitus in Africa and the Middle East on antidiabetic therapies necessitate an understanding of adverse event reporting in these regions. We assessed pharmaceutical industry insulin individual case safety report (ICSR) completeness and completeness-associated variables.

RESEARCH DESIGN AND METHODS

The observational cross-sectional study, set in an insulin-manufacturing company's safety database, assessed vigiGrade® completeness scores of African and Middle Eastern post-marketing ICSRs during January to December 2018, and the effects of case variables on completeness. Low vigiGrade® scores indicated poorly documented ICSRs.

RESULTS

We analyzed 4854 ICSRs; 59.8% from the Middle East. The mean vigiGrade® score was 0.58. Middle Eastern ICSRs had higher mean scores than African ICSRs (0.65 vs. 0.46, p<0.001). Scores peaked at 0.32, 0.70, and 1.00, for Middle Eastern ICSRs compared to 0.35 and 0.50 for African ICSRs. Middle Eastern serious (0.77 vs. 0.47; p<0.001) and solicited (0.70 vs. 0.48; p<0.001) ICSRs had higher mean scores than African ICSRs. Mean scores were highest for Middle Eastern physicians (0.89) and other healthcare professionals (0.82) whereas, in Africa, scores were highest for consumer- (0.47) and pharmacist-reported ICSRs (0.47) (p<0.001).

CONCLUSIONS

Middle Eastern pharmaceutical industry insulin ICSRs were documented with greater detail than African ICSRs. Event seriousness, report source, and reporter type significantly impacted ICSR completeness.

Adverse Event Following Immunization (AEFI) in Children: An Analysis of Reporting in VigiAccess

INTRODUCTION

It is an indubitable fact that vaccination has been instrumental in the eradication and prevention of the deadliest diseases worldwide. Continuous vaccine safety surveillance is helpful to counter the negative perception and thus allay the fear of Adverse Events Following Immunization (AEFI) in the general public. VigiAccess, the WHO global database of reported side effects of medicinal products, can be accessed by the public at large. The objective of this study is to assess the characteristics of AEFIs of the commonly used vaccines in children in VigiAccess.

MATERIALS AND METHODS

VigiAccess was thoroughly explored for the categories, number, and types of AEFIs of commonly used vaccines among children that are reported in five continents between 2011 and 2021.

RESULTS

After a comprehensive analysis in VigiAccess, 27 kinds of AEFIs were discovered. For the nine vaccines, a total of 1,412,339 AEFIs were found. The most prevalent AEFIs were general disorder and administration site condition (436,199 or 30%). The majority of AEFIs are found in America, with Europe, Oceania, Asia, and Africa following closely behind. Girls of age from 27 days to 23 months had the highest number of AEFIs. The highest number of AEFIs was recorded in the year 2018.

CONCLUSION

America has the maximum, whilst Africa has the least AEFI. Few AEFIs were caused by the measles vaccination, while the majority were related to the general disorder and administration site condition. Data synchronization in VigiAccess needs to be enhanced to improve its dependability.

Adverse event following vaccine surveillance in Kaduna State, Northwestern Nigeria (January 2018 -June 2019): analysis of health facility´s records

INTRODUCTION

Adverse Events Following Immunization (AEFI) are one of the main reasons for inadequate immunization coverage in Kaduna State, and AEFI underreporting serves as a barrier to achieving goals of global pharmaco-vigilance for vaccine. The purpose of this study is to estimate the completeness of variables in the AEFI line-listing forms, calculate AEFI reporting rates by Local Government Areas & vaccine type and profile the reported cases according to their reactions.

METHODS

we conducted a descriptive, cross-sectional, retrospective study of primary surveillance records. We calculated AEFI reporting rates in the State and Local Government areas and AEFI Vaccine reaction rates to the various antigens. We used Binary logistic regression to determine the association between gender and vaccine reactions.

RESULTS

seven thousand eight hundred and twenty-four (7,824) AEFI cases were reported. The completeness of variables on the filled AEFI line-list varied from 21% to 100%. The State had a high AEFI reporting rate of 9.09 per 10,000 administered doses. Fever (<38oC) was the main AEFI reaction. Severe AEFI cases accounted for only 0.89% of the total reported cases. Pentavalent vaccine was the suspect antigen responsible for the highest number of AEFI cases, with a vaccine reaction rate of 44.77 per 10,000 doses. The Zaria Local Government area had the highest AEFI reporting rate, while the Sanga Local Government area had the lowest AEFI reporting rate in the State. The difference between genders in the number of reported AEFI cases was not statistically significant (p>0.05). There were 35% higher odds of occurrence of bleeding among males than among females (aOR: 1.354; P-value: p=.012; 95% CI: 1.070-1.715; Nagelkerke-R^2-: 0.003). The other reactions were not significantly related to gender.

CONCLUSION

our study shows a higher occurrence of severe AEFI in subjects undergoing pentavalent vaccine. Thiscaused the highest incidence of AEFI. There was no significant association between gender and AEFI reactions.

Using Population-Based Structures to Actively Monitor AEFIs during a Mass Immunization Campaign-A Case of Measles-Rubella and Polio Vaccines

Active vaccine pharmacovigilance complements the standard passive or spontaneous surveillance system, which suffers from low reporting rates. This study aimed at utilizing population-based structures to report and profile adverse events following immunization (AEFI) with the measles and rubella vaccine (MR), or MR in combination with the bivalent oral polio vaccine (bOPV 1&3) (MR & bOPV), during mass vaccination in Uganda. Caretakers of children at home (less than 5 years) and schoolgoing children were followed up on and encouraged to report any AEFIs on day one, 2-3 days, 10 days, and 14 days after vaccination at school by their teachers and at-home, community-based village health teams. Out of 9798 children followed up on, 382 (3.9%) reported at least one AEFI, and in total, 517 AEFIs were reported. For MR, high temperature (21%), general feeling of weakness (19.3%), and headache (13%) were the most reported AEFIs, though there were variations on the days when they were reported. For the combination dose of MR & bOPV, high temperature (44%), rash (17%), general feeling of weakness (13%), and diarrhoea (8%) were the most common adverse events following immunization reported by caretakers. All 382 children cleared the AEFIs within 2 days, with 343 (90%) children reporting mild or moderate AEFIs and only 39 (10%) reporting severe AEFIs. The reported AEFIs are known and are mentioned in the vaccine leaflets with similar severity classification. Rates of AEFIs differed with the number of days after receiving the immunization. Conclusion: Active surveillance for AEFIs provides additional important information to national vaccine regulatory bodies. It reassures the public that vaccines are safe and that their safety is being taken seriously in Uganda, which would improve vaccine acceptability and confidence in the health system. Piggybacking on existing structures such as village health team members (for children at home) and teachers (for schoolgoing children) facilitates reaching vaccine recipients and increases reporting rates. Therefore, studies using active reporting of AEFIs should be conducted at regular intervals to report the overall incidence of AEs and to monitor trends and changes.

Adverse events following immunization: Findings from 2017/2018 measles vaccination campaign, Nigeria AEFI reporting in 2017/2018 measles vaccination campaign

INTRODUCTION

An Adverse event following immunization (AEFI) is an untoward medical occurrence following immunization and which may not have a necessary causal relationship with the usage of a vaccine. The World Health Organization categories AEFI into two; serious and non-serious. An AEFI is considered serious if it is life-threatening, requires inpatient hospitalization or results in death. The measles vaccine is safe and effective however because it is a live-attenuated injectable vaccine it is more prone to AEFI as compared to non-injectable vaccines when given in large numbers over a short period as is the nature of measles mass vaccination campaigns (MVC). This article describes Nigeria's experience on AEFI reporting during the 2017/2018 Measles vaccination campaign (MVC).

METHODS

We reviewed various materials which included the Open Data Kit (ODK) which is an open source smartphone-based data collecting tool, operations room reports, measles campaign tally sheets, AEFI line listing forms, the post measles campaign coverage survey report and the report of the AEFI national expert committee review of the 2017/2018 Nigeria measles MVC.

RESULTS

A total of 6,214 suspected cases of AEFI were line listed from all 36 states and the Federal Capital Territory(FCT) during the 2017/2018 MVC with Fever(38%) and pain at injection site the (30%)most common reports. Overall, 99.7% AEFIs were reported to be non-serious AEFIs, with almost all cases resolved fully with no long-term sequalae.. The national incidence of suspected AEFI per 100,000 population was 16.3 with subnational incidence highest in Kebbi state (101.3/100,000) and lowest in Bayelsa state (0.8/100,000).

CONCLUSION

Adequate AEFI reporting, Investigation and management remains important in managing the risk of a disruption of mass campaigns. The deployment of supervisors during campaign may play an important role in improving the identification and reporting of suspected AEFI. Further inquiries about AEFIs during the post campaign coverage evaluation also played a role in improving AEFI reporting and documentation. The real-time, on the spot, follow up by the national operations team helped with decision making and intervention including AEFI investigations and assessments.