Reports Of Adverse Events Following Immunization Research Articles

National safety monitoring of vaccines from the Canadian Adverse Events Following Immunization Surveillance System (CAEFISS), 2018-2019.

The Canadian Adverse Events Following Immunization Surveillance System (CAEFISS) is a comprehensive vaccine safety surveillance system that includes both passive and active surveillance of vaccines administered in Canada. This work presents a summary of adverse events following immunization (AEFI) nationally for 2018 and 2019. Data extracted from CAEFISS included all AEFI reports received by the Public Health Agency of Canada by April 30, 2022, for vaccines marketed in Canada and administered between January 1, 2018, and December 31, 2019. Descriptive statistics were conducted on AEFI reports by type of surveillance program (i.e., active vs. passive), AEFIs, demographics, healthcare utilization, outcome, seriousness of adverse events and type of vaccine. Between 2018 and 2019, 5,875 AEFI reports were received from across Canada. The average annual AEFI reporting rate was 10.9/100,000 doses distributed in Canada for vaccines administered during 2018-2019 and was found to be inversely proportional to age. The majority of reports (91%) were non-serious events, involving vaccination site reactions, rash and allergic events. Overall, there were 511 serious adverse event reports during 2018-2019. Of the serious adverse event reports, the most common primary AEFIs were anaphylaxis followed by seizure. There were no unexpected vaccine safety issues identified or increases in frequency or severity of adverse events. Canada's continuous monitoring of the safety of marketed vaccines during 2018-2019 did not identify any increase in the frequency or severity of AEFIs, previously unknown AEFIs, or areas that required further investigation or research.

Canadian vaccine safety surveillance reports following immunization with seasonal influenza vaccines, 2021-2022.

Seasonal influenza vaccines (SIV) authorized for use in Canada have all undergone rigorous regulatory assessments for safety and effectiveness. Serious adverse events following immunization (AEFI) can occur, though they are rare. Continuous safety surveillance of vaccines during the post-marketing phase is a critical component of vaccination programs. This enables the detection of rare, late onset, or unexpected adverse events. An updated safety summary following the introduction of any new vaccines and/or formulations to immunization programs is necessary for refining the risk-benefit profile of a specific vaccine and maintaining public confidence. Here we provide an updated safety summary for SIVs distributed during the 2021/2022 influenza season from AEFI reports submitted to the Canadian Adverse Event Following Immunization Surveillance System (CAEFISS) and the Canadian Vigilance Database (CVD). We searched CAEFISS and CVD for individuals who were vaccinated with a SIV between October 1, 2021, and March 31, 2022. Descriptive statistics were calculated, including median age of vaccinated individuals, vaccines co-administered with SIV, and the most frequently reported AEFIs. Crude AEFI reporting rates were calculated by severity of the AEFI report, and SIV-type using doses distributed data. Medical reviews were conducted for reports including death, serious events (or outcomes) after SIV were administered alone, and selected adverse events (i.e., anaphylaxis, Guillain-Barré syndrome, febrile seizures, oculo-respiratory syndrome). Disproportionality analysis was used to identify potential safety signals among SIV and AEFI pairs. There were 448 AEFI reports, with most AEFI classified as non-serious events (84.2%). The majority of reports described vaccination in adults at least 65 years of age (38.6%). The most frequently reported AEFIs were vaccination site pain, urticaria, pyrexia and rash. Medical review of AEFI reports did not find any evidence that reported deaths were related to vaccination with SIV. Among serious reports, nervous system disorders were the most commonly reported medical conditions. A higher number of events related to vaccination errors were also identified using disproportionality analysis. Findings from our analysis of reports to CAEFISS and CVD following vaccination with SIV are consistent with the known safety profile of SIVs distributed during the 2021/2022 influenza season. The majority of reports were non-serious with the most common AEFI symptoms occurring at the vaccination site or systemic symptoms that were self-limiting. The majority of vaccination error reports involved the administration of the vaccine at an inappropriate site, although no serious AEFIs were reported.

Adverse events following immunization reported with COVID-19 vaccines in Burkina Faso: Analysis of spontaneous reports

The rapid deployment of COVID-19 vaccines to a large proportion of the population requires a focus on safety. However, few studies have assessed the safety of COVID-19 vaccines in Africa. In Burkina Faso, this issue has not yet been addressed. The objective of this study was to contribute to the description of the characteristics of adverse events following immunization (AEFIs) related to COVID-19 vaccines in Burkina Faso. This was a cross-sectional descriptive retrospective study of spontaneous reports of COVID-19 vaccine-related AEFIs recorded in VigiBase® between June 2021 and November 2022 in Burkina Faso. Individual case safety reports (ICSRs) were extracted from VigiBase® using the Anatomical Therapeutic Chemical level 2 (ATC2) code. The proportion of ICSRs according to the reporter’s qualification, the reporting rate, the time taken to submit and record ICSRs, and the completeness score were calculated. A total of 973 ICSRs concerned COVID-19 vaccines and represented 32.6% of all 2,988 reports in VigiBase®. Overall, 82.0% of the reporters were nurses/midwives, 7.8% were physicians, 6.7% were pharmacists, and 3.4% were patients. The median time between the onset of AEFIs and the submission of the report to the Pharmacovigilance Center was 180 days (IQR: 136; 281). The median registration time was 188 days (IQR: 149; 286). The mean ICSR completeness score was 0.8 (standard deviation = 0.1). The overall AEFI reporting rate was 27.8 per 100,000 vaccine doses. The AEFI reporting rates for the ChAdOx1-nCoV-19, JNJ 78436735, Elasomeran, Tozinameran, and HB02 vaccines were 454.2, 17.4, 11.0, 10.2, and 0.4 per 100,000 vaccine doses, respectively. The majority of AEFIs were systemic in nature (90.1%). Headache (21.2%), fever (19.4%), and myalgia (11.0%) were the most frequently reported AEFIs. Eighteen cases (1.8%) of serious AEFIs (9 hospitalizations, 4 life threatening, 3 temporary disabilities, and 2 others unspecified) were reported. The majority of AEFIs reported were systemic in nature and mild. However, there have been reports of serious AEFIs. The overall AEFI reporting rate was low. There is a need to strengthen the monitoring of these vaccines to better organize strategies to optimize the adherence of the population of Burkina Faso.

Intussusception and Other Adverse Event Surveillance after Pilot Introduction of Rotavirus Vaccine in Nam Dinh and Thua Thien Hue Provinces-Vietnam, 2017-2021.

Rotavin-M1 (POLYVAC) was licensed in Vietnam in 2012. The association of Rotavin-M1 with intussusception, a rare adverse event associated with rotavirus vaccines, and with adverse events following immunization (AEFI) have not been evaluated and monitored under conditions of routine use. From February 2017 to May 2021, we conducted a pilot introduction of Rotavin-M1 into the routine vaccination program in two provinces. Surveillance for intussusception was conducted at six sentinel hospitals. AEFI reports at 30 min and 7 days after vaccination were recorded. Among 443 children <12 months of age admitted for intussusception, most (92.3%) were children ≥ 6 months. Of the 388 children who were age-eligible to receive Rotavin-M1, 116 (29.9%) had received ≥1 dose. No intussusception cases occurred in the 1-21 days after dose 1 and one case occurred on day 21 after dose 2. Among the 45,367 children who received ≥1 dose of Rotavin-M1, 9.5% of children reported at least one AEFI after dose 1 and 7.3% after dose 2. Significantly higher AEFI rates occurred among children given Rotavin-M1 with pentavalent vaccines (Quinvaxem®, ComBE Five®) compared to Rotavin-M1 without pentavalent vaccines. There was no association between intussusception and Rotavin-M1. The vaccine was generally safe when administered alone and when co-administered with other vaccines.

Adverse events following immunization (AEFIs) with anti-meningococcus type B vaccine (4CMenB): Data of post-marketing active surveillance program. Apulia Region (Italy), 2019–2023

The four-component recombinant-DNA anti-meningococcus B vaccine (4CMenB) has been approved by the European Medicines Agency in 2013. In Italy, 4CMenB is recommended since 2017 for use in infants under one year of age. Due to the strong evidence of increased risk of fever after administration, surveillance of adverse events following immunization (AEFIs) is a priority for 4CMenB.This cross-sectional prospective study aims at investigating 4CMenB’s safety profile. The study population is represented by infants under twelve months of age vaccinated with 4CMenB in selected ambulatories in Apulia, a region in South-Eastern Italy, from October 1st, 2020, to March 31st, 2023. Parents were provided with a post-vaccination diary covering up to seven days after immunization and were contacted one week after the vaccination day. Information about AEFIs was collected, and reactions were classified following World Health Organization guidelines. For serious AEFIs, causality assessment was carried out. AEFI risk determinants were investigated via logistic regression.A total of 4,773 diaries were completed, with 78.13 % of them (3,729/4,773) containing one or more AEFI reports. Systemic reactions such as malaise, drowsiness/insomnia and fatigue were the most common ones, followed by fever and local pain, tenderness, redness and swelling.Twenty-three cases of serious AEFIs were reported. Following causality assessment, 78.26 % of serious adverse events (18/23) were deemed to have a consistent causal association with the administration of 4CMenB (reporting rate: 0.38 %). Three infants were hospitalized following vaccination, but no cases of death or permanent/severe impairment were reported. Prophylactic paracetamol administration showed a significant protective effect against the risk of manifesting fever within the first 24 h after administration (OR: 0.75; p < 0.005).Our data confirms existing evidence regarding the safety of 4CMenB vaccination in babies under 2 years of age, but also highlight a significant risk of fever after vaccination. Prophylactic paracetamol administration could represent a protective factor against fever, especially during the first 24 h after vaccination.

Imprecision in vaccine adverse event reporting and a methodological analysis of reporting systems to improve pharmacovigilance and public health.

This study documents imprecision in Japanese reports of adverse events following immunization (AEFI). In doing so, it presents methods to analyze this imprecision. These methods include use of unique Japanese data on the validity of certain AEFIs. They also include ways to estimate AEFI rates, which allow comparison of AEFI data between countries. Using US AEFI data for comparison, we show how differences in AEFI reporting systems likely influence AEFI statistics. Although our comparisons of AEFI rates are not precise, many of the difference we detected between Japanese and US statistics make sense and reflect differences in the societal and medical perspectives on various vaccines or can be explained by differences in the reporting systems including reporting sources. For example, differences in societal and medical perspective probably underly the extraordinarily high Japanese rates of anaphylaxis and other AEs following HPV immunizations from 2010 to 2016 compared to US rates and to Japanese rates for other vaccines. High US rates of reported Guillain-Barré syndrome following influenza vaccination relative to Japanese rates and to rates for other US vaccines are consistent with data suggesting that the index of suspicion for such reactions could affect AEFI rates. The findings that over half of Japanese anaphylaxis reports for every vaccine are erroneous, and that close to half of "serious" Japanese AEFI cases probably are not serious may be due in part not only to explanations unique to Japan, but also to factors that apply to the USA and other countries. Differences in reporting systems account for a much higher rate of non-serious AEFI reports in the USA compared to Japan. Japanese marketing authorization holders are probably at least as assiduous and timely in their reporting of AEFIs as health care providers, though granular level differences are apparent in reporting by various sources. The methods we used to analyze the validity of Japanese statistics can be used to analyze the validity of AEFI reports from other countries and aid the harmonization of adverse event reporting systems. Eventually, similar reporting systems might be adapted for drugs and medical devices.

Safety of mRNA vaccination for COVID‐19 in children with polyethylene glycol (PEG)‐asparaginase allergy

Safety of <scp>mRNA</scp> vaccination for <scp>COVID</scp>‐19 in children with polyethylene glycol (<scp>PEG</scp>)‐asparaginase allergy

Descriptive Research Study of the Adverse Events Following Immunization (AEFIs) Surveillance System in Zimbabwe

Aim: Functional national systems that monitor Adverse Events Following Immunization (AEFIs) are vital for implementing evidence-based vaccination policy while ensuring the safe access to these life-saving technologies. These systems can counteract vaccine hesitancy by increasing public trust and uptake in vaccination minimizing the burden of vaccine-preventable diseases (VPDs). Ensuring that these systems function optimally is a critical public health imperative. This is a novel study evaluating AEFI surveillance system including causality assessment, in Zimbabwe. This study provides a review of Zimbabwe’s national AEFI surveillance system since its launch in 1998, highlighting strengths, weaknesses, and opportunities for improvement. Materials and Methods: We conducted an in-depth analysis of all AEFI reports received until 2021, assessing reporting trends and overall performance of the AEFI system in terms of investigation, causality assessment. The WHO Global Benchmarking Tool (GBT) was used to assess regulatory performance in terms of AEFI surveillance. Duplications were excluded and reports with evidence of AEFI(s) after vaccination were included by examining the WHO 25 AEFI form core variables. Results: There was a steady increase of AEFI reports per annum particularly from 2006 to 2021 with a more dramatic increase during the COVID-19 epidemic with an AEFI reporting ratio of 43.46/million adults for COVID-19 vaccinations in 2021. The reporting ratio exceeded the WHO recommended minimum AEFI reporting ratio of 10 per 100000 surviving infants during eleven years (47.84%) out of the twenty-three years since inception of the surveillance. The GBT assessment demonstrated that the AEFI surveillance system evolved for all manufacturers or license holders. Conclusion: Close partnership between the immunization program and regulatory authority has enhanced AEFI surveillance in Zimbabwe. Incomplete AEFI case investigations for and timely AEFI detection are challenges that need to be addressed. System strengthening should include consideration of digital innovations to improve detection, optimizing case investigation of serious AEFI including post-mortems and utilizing VigiPoint disproportionate analysis for signal detection.

Surveillance of Vaccination Coverage of Inactivated Influenza Vaccines and Allergic Rash Adverse Events Following Immunization for Children From 6 Manufacturers.

The composition of influenza vaccines is updated annually. To ensure vaccine safety, the coverage and adverse events following immunization (AEFI) of 6 manufacturers of trivalent inactivated influenza vaccine (TIV3) need to be evaluated. In January 2022, we analyzed data from more than 1.59 million children in the Childhood Vaccination Information Management System and the AEFI Surveillance Information Management System and evaluated influenza vaccines for children aged 6 to 35 months in Guangzhou from 2016/17 to 2019/20 Vaccination rates and AEFI reporting rates. From 2016/17 to 2019/20, the 1-dose influenza vaccination rate was 25.0% (range: 20.7%-30.2%), and the 2-dose (full course) influenza vaccination rate was 21.6% (range: 17.7%-26.4%). The full vaccination coverage rate has trended down since 2017/2018 (2017/18: 26.0%; 2018/19: 8.3; 2019/20: 17.7%). Fifty-two cases (13.1/100 000) and 24 cases (6.9/100 000) received AEFI reports for 1 dose and 2 doses, respectively, mainly due to fever ≥38.6°C (39 cases for 1 dose, 9.8/100 000; 15 cases for 2 dose, 4.3/100 000) and allergic rash (9 cases with 1 dose, 2.3/100 000; 5 cases with 2 doses, 1.4/100 000). Patients who received A and F manufacturers were more likely to report side effects. The safety of influenza vaccines from 6 manufacturers is good, and it is necessary to improve the recommended information on influenza vaccines to dispel people's concerns and increase the vaccination rate.

Imprecision in adverse event reports following immunization against HPV in Japan and COVID-19 in the USA, UK, and Japan-and the effects of vaccine hesitancy and government policy.

Erroneous reports of adverse events following immunization (AEFIs) likely exacerbated the 2013 collapse of Japan's HPV immunization program. A similar phenomenon characterized the first months of COVID-19 immunization programs in the USA, UK, and Japan with high rates of reportedanaphylaxis. These reports illustrate the susceptibility of supposedly objective medical judgments to public anxiety. This study documents inaccuracies in reportedAEFIs using three quantitative methods. One of these quantitative methods revealed that false-positive rates for anaphylaxis reports following HPV and later COVID-19 vaccination ranged from 74 to 91 percent. However, unlike HPV vaccinations in Japan, anaphylaxis reportsfollowing COVID-19 vaccines fell in Japan, the USA and theUK in the latter months of 2021. Nevertheless, false-positive rates for anaphylaxis reports remained high, suggesting a high degree of imprecision in serious AEFI reports from many countriesfor many vaccines. Japan's HPV immunization program indicates that media reports, patient hesitancy, healthcare providers' perspectives on vaccine safety, and consistency of government messaging, all influence report number and accuracy. A parallel publication analyzes in depth how such factors affect AEFI reports. Confidence in the safety of the COVID-19 vaccines may have been bolstered trough rapid monitoring of AEFI reports and communication ofthese findings. This may partly explain the different trajectories of serious AEFI following HPV immunizations in Japan and COVID-19 immunizations in the USA, UK, and Japan.

Real-world safety profile of the 9-valent human papillomavirus vaccine: A study in Zhejiang, China from 2019 to 2021

ABSTRACT The safety profile of the 9-valent human papillomavirus vaccine (9vHPV) was evaluated based on the reporting rate of adverse events following immunization (AEFI) obtained from the passive surveillance data in Zhejiang. The 9vHPV AEFI reports in Zhejiang were collected and reviewed from the National Adverse Event Following Immunization Surveillance System (NAEFISS) from 2019 to 2021. Reporting rates of AEFI were analyzed under multiple aspects, including age, city, number of vaccinations, AEFI categories, and diagnosis categories. This study used the reporting odds ratio (ROR) for anomalous signal assessment. The NAEFISS collected 331 AEFI reports after administering 1,064,851 doses of 9vHPV, with a crude AEFI rate of 3.12/10,000 doses. The third dose had the highest reporting rate of minor vaccine-related reaction (n = 80, 3.06 per 10,000), followed by the first dose (n = 134, 2.98 per 10,000), and second dose (n = 76, 2.15 per 10,000). Fever/redness/induration was the most common minor adverse event (281 records, 2.64/10,000 doses). Nine cases of urticaria, ten cases of allergic rash, and ten cases of syncope were recorded. This study found a positive signal association between 9vHPV immunization and adverse events such as syncope, encephalitis, sterile abscess, and urticaria. This study did not identify any new emerging safety concerns. In the future, more research is needed to validate and further explore adverse reactions associated with 9vHPV.

Vaccine safety in Australia during the COVID-19 pandemic: Lessons learned on the frontline.

Surveillance of Adverse Events Following Vaccination in the Community (SAEFVIC), Victoria's vaccine safety service for reporting adverse events following immunisation (AEFI), has provided integrated spontaneous surveillance and clinical services for individuals affected by AEFI since 2007. We describe SAEFVIC's response to the COVID-19 vaccine program, and reflect on lessons learned for vaccine safety. The massive scale of the Australian COVID-19 vaccine program required rapid adaptations across all aspects of SAEFVIC's vaccine safety services. Collection of AEFI reports was streamlined and expanded, incorporating both spontaneous and active surveillance data. Dramatically increased report volumes were managed with additional staffing, and innovations to automate, filter, and triage reports for priority follow up. There were two major adverse events of special interest (AESI): thrombosis with thrombocytopaenia syndrome and myocarditis, with multiple other AESI also investigated. Rapid escalation mechanisms to respond to AESI were established, along with AESI-specific databases for enhanced monitoring. Vaccine education and training resources were developed and public-facing vaccine safety reports updated weekly. Frequent communication with local and national government and regulatory bodies, and consultation with specialist groups was essential. The COVID-19 vaccine program has highlighted the importance of vaccine safety in supporting public confidence in vaccines and informing evidence-based immunisation policy. Supporting the COVID-19 vaccine program has required flexibility in adapting to policy changes and evolving vaccine safety signals, careful triage and prioritisation, informatics innovation, and enhanced engagement with the public regarding vaccine safety. Long-term investment to continue strengthening vaccine safety systems, building on lessons learned, will be essential for the ongoing success of Australian vaccination programs.

Does This COVID 19 Pandemic Demand a Scale Up in AEFI Reporting in India?

The COVID-19 Pandemic has changed the global picture in the field of public health in the past few years. This critical time has made life very uncertain for everyone. Man has been constantly striving to discover measures to stop the spread of this deadly virus; the COVID-19 vaccine is one such endeavour. The fear and anxiety towards a new vaccine is high among the general public. With every new vaccination, constant monitoring and documentation of the vital happenings is very important. Thus, the reporting of Adverse events following immunization (AEFI) needs to be strengthened and implemented more efficiently to analyse the efficacy of this vaccination drive with respect to protection from the disease without causing any harmful adverse effects.

Psychological and Psychiatric Events Following Immunization with Five Different Vaccines against SARS-CoV-2.

Background: Despite the high number of vaccines administered against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide, the information on the psychological/psychiatric adverse events following immunization (AEFI) with these newly developed vaccines remains scarce. Objective: To describe the frequency of psychological/psychiatric symptoms among recipients of five different anti-SARS-CoV-2 vaccines and to explore the factors associated with their development reported in the nationwide Mexican registry of AEFI against SARS-CoV-2. Methods: Descriptive study of all the psychological/psychiatric symptoms, including anxiety, panic attacks, insomnia, and agitation reported to the Mexican Epidemiological Surveillance System from 21 December 2020 to 27 April 2021, among adult (≥18 years old) recipients of 7,812,845 doses of BNT162b2, ChAdOx1 nCov-19, rAd26-rAd5, Ad5-nCoV, or CoronaVac. The factors associated with their development are determined by multivariate regression analysis. Results: There were 19,163 AEFI reports during the study period; amongst them, 191 (1%) patients had psychological/psychiatric symptoms (median age of 41 years, interquartile range of 32–54; 149 [78%] women) for an observed incidence of 2.44 cases per 100,000 administered doses (95% confidence interval [CI] 2.12–2.82), 72.8% of psychiatric AEFIs were reported among recipients of BNT162b2. The median time from vaccination to symptom onset was 35 min (interquartile range: 10–720). Overall, the most common psychological/psychiatric symptoms were anxiety in 129 (67.5%) patients, panic attacks in 30 (15.7%), insomnia in 25 (13%), and agitation in 11 (5.7%). After adjusting for the confounding factors, the odds for developing psychological/psychiatric symptoms were higher for those concurrently reporting syncope (odds ratio [OR]: 4.73, 95% CI: 1.68–13.33); palpitations (OR: 2.47, 95% CI: 1.65–3.70), and dizziness (OR: 1.59, 95% CI: 1.10–2.28). Conclusion: In our population, psychological/psychiatric symptoms were extremely infrequent AEFIs. No severe psychiatric AEFIs were reported. Immunization stress-related responses might explain most of the detected cases.

COVID-19 Vaccine Hesitancy: The Perils of Peddling Science by Social Media and the Lay Press.

Introduction: Vaccines are the best tools to end the pandemic, and their public acceptance is crucial in achieving herd immunity. Despite global efforts to increase access to vaccination, the World Health Organization explicitly lists vaccination hesitancy (VH) as a significant threat. Despite robust safety reports from regulatory authorities and public health advisories, a substantial proportion of the community remains obsessed with the hazards of vaccination. This calls for identifying and eliminating possible causative elements, among which this study investigates the inappropriate dissemination of medical literature concerning COVID-19 and adverse events following immunization (AEFI), its influence on promoting VH, and proposals for overcoming this problem in the future. Methods: We searched PubMed, Embase, and Scopus databases, using the keywords “adverse events following immunization (AEFI)”, “COVID-19”, “vaccines” and “hesitancy” and related medical and subjective headings (MeSH) up to 31 March 2022, and extracted studies relevant to the COVID-19 AEFI and associated VH. Finally, 47 articles were chosen to generate a narrative synthesis. Results: The databases depicted a steep rise in publications on COVID-19 AEFI and COVID-19 VH from January 2021 onwards. The articles depicted multiple events of mild AEFIs without fatal events in recipients. While documenting AEFIs is praiseworthy, publishing such reports without prior expert surveillance can exaggerate public apprehension and inappropriately fuel VH. VH is a deep-rooted phenomenon, but it is difficult to zero in on the exact reason for it. Spreading rumors/misinformation on COVID-19 vaccines might be an important provocation for VH, which includes indiscriminately reporting AEFI on a massive scale. While a number of reported AEFIs fall within the acceptable limits in the course of extensive COVID-19 vaccinations, it is important to critically evaluate and moderate the reporting and dissemination of AEFI in order to allay panic. Conclusions: Vaccination programs are necessary to end any pandemic, and VH may be attributed to multiple reasons. VH may be assuaged by initiating educational programs on the importance of vaccination, raising public awareness and monitoring the inappropriate dissemination of misleading information. Government-initiated strategies can potentially restrict random AEFI reports from lay epidemiologists and healthcare practitioners.

Central nervous system adverse events after ChAdOx1 vaccination.

IntroductionPost-ChAdOx1 vaccine (AZD1222) adverse events following immunization (AEFI) are uncommon. Recently described neurological events include thrombocytopenia with thrombosis syndrome (TTS) with cerebral venous thrombosis and Guillain-Barré syndrome. There are very few AEFI reports following COVID vaccination from India, because of underreporting or other factors. A few cases of acute transverse myelitis (ATM) and post-vaccinal encephalitis have also been reported.Materials and methodsOver 11 months, in 2 districts of Kerala, India, 8.19 million people were vaccinated with the ChAdOx1 vaccine.ResultsDuring this period, we encountered five cases of autoimmune central nervous system (CNS) AEFI following ChAdOX1 (Oxford/AstraZeneca, Covishield™) vaccination. These included three cases of acute disseminated encephalomyelitis (ADEM), one case of opsoclonus myoclonus ataxia syndrome (OMAS), and one case of limbic encephalitis. The calculated crude incidence of post-ChAdOX1 autoimmune CNS AEFI was approximately 0.24 cases per million for encephalitis and 0.36 per million for ADEM. This was compared to the crude annual incidence of community-acquired ADEM worldwide (3.2–4 per million) and the crude annual incidence of community-acquired encephalitis in India (8.35–10 per million).ConclusionThere was no increase in the incidence of post-vaccination CNS AEFI (ADEM or encephalitis) as compared to the community incidence of ADEM or encephalitis. While this emphasizes the safety of ChAdOX1 nCoV-19 vaccination for COVID-19, it is important to recognize these post-vaccination autoimmune syndromes early to initiate immunosuppressive therapy.

Surveillance on the adverse events following immunization with the pentavalent vaccine in Zhejiang, China

ABSTRACT Objectives The aim of this study is to describe the reporting rate of adverse events following immunization (AEFI) with pentavalent vaccine: diphtheria-pertussis-tetanus-poliomyelitis-Haemophilus influenzae type b (DPT-IPV/Hib), and to determine whether the reporting rate of AEFI following DPT-IPV/Hib was higher than the average level of the other vaccines. Methods Review and describe the AEFI reported to national adverse event following immunization surveillance system (NAEFISS) in Zhejiang province from 2015 to 2020. Reporting rates of AEFI were calculated by age, city, severity of AEFI, categories of AEFI, and reaction categories. The data mining algorithm used in this study was reporting odds ratio (ROR). A value of ROR‑1.96SE >1 (standard error [SE]) was considered as positive signal. Results NAEFISS received 5726 AEFI reports following DTP-IPV/Hib, with a reporting rate of 20.01/10000 doses. Of the reported AEFI, 202 were serious vaccine product-related reactions, including two cases of anaphylactic shock, five cases of Guillain Barre Syndrome (GBS) and two cases of acute disseminated encephalomyelitis. The reporting rate of fever/redness/induration was the highest among all the clinical diagnosis (14.97/10000 doses). The positive signals were obtained for allergic rash (ROR-1.96SE: 1.36), febrile convulsion (ROR-1.96SE: 1.32) and GBS (ROR-1.96SE: 1.16). Conclusion The present findings bolstered that the DTP-IPV/Hib administered as the four-dose schedule was generally well tolerated in Chinese infants as we did not identify any new/unexpected safety concern from the NAEFISS during a six-year timespan.

Monitoring the safety of influenza A/H1N1 pandemic and seasonal vaccines in Morocco.

Background:A vaccination campaign against pandemic influenza A/H1N1 was implemented in Morocco between November 2009 and April 2010. Overall, 705,883 subjects were vaccinated by Pandemrix, Arepanrix, and Panenza. The adverse events following immunization (AEFIs) data comparison was made with the 2014/2015 seasonal influenza vaccination campaign that was specifically investigated.Aim:To evaluate the safety of the 2009 pandemic influenza A/H1N1 vaccine and to compare it to that of 2014 seasonal influenza vaccine.Methods:During the pandemic vaccination campaign, the Morocco Pharmacovigilance Centre reinforced passive AEFI surveillance with an active and prospective monitoring programme of 1000 immunized people over 6 months at 10 randomly selected vaccination centres. For the 2014/2015 seasonal vaccination campaign, AEFI data were collected from spontaneous notifications.Results:Active monitoring of 2009 pandemic collected 771 AEFI reports, corresponding to an AEFI incidence rate of 77.1% with vaccination by either Pandemrix or Arepanrix vaccine in 95% of cases. Reported AEFI were most frequently local (37.7%), general (29.5%), and neurological reactions (20.3%). Most of the AEFI (95.5%) were observed during the first 48 hours after vaccination, and the remainder within 2 weeks. None of the reported AEFI were serious case. The highest rate of notification was documented for health professionals, followed by patients with diabetes or chronic respiratory diseases. Concerning passive surveillance, the AEFI notification rate was significantly higher for the 2009/2010 pandemic vaccine (3.1 vs 1.2 per 10,000). However, there was no significant difference between pandemic and seasonal vaccination with regards to the serious adverse events (SAE) notification rate (0.3 vs 0.2 per 10,000).Conclusion:Data analysis indicates that the vaccines used against 2009 pandemic influenza in Morocco have a satisfactory safety profile, similar to the seasonal influenza vaccine with the exception of local reactions as observed previously in other countries.

Smartphone-based active vaccine safety surveillance (SmartVax) at a Swiss adult vaccination clinic - a pilot study.

Post-licensure surveillance of adverse events following immunisation (AEFI) is critical for detecting rare but severe AEFI. SmartVax software, using smartphone technology, actively solicits reports of AEFI via automated, opt-out SMS surveys to vaccine recipients in the days following immunisation. We report on a pilot study to test the feasibility and acceptance of SmartVax in Switzerland. Between February and September 2020, consecutive subjects immunised at an adult immunisation clinic and the employee health service at the University Hospital of Basel were screened. Participants included three subgroups: healthcare workers (HCW), subjects with immune-mediated inflammatory diseases (IMID) and clients of the regular adult immunisation clinic. Three days after vaccination, participants received an SMS inquiring if they had any AEFI. In the case of an AEFI, subjects received an automated SMS with a link to an online survey assessing the type and temporal evolution of the AEFI. Descriptive statistics of response rate, time-to-response, frequency and type of AEFI by vaccine and clinical subgroup were performed. Of 293 subjects screened, 276 were included (46.6% routine vaccination check-up visits, 33.3% HCW, 20.1% IMID patients) receiving 625 vaccinations during 360 immunisation visits. The SMS response rate was high (90.3%), with a median time-to-respond of 47 minutes (interquartile range11-205). After 29.8% of immunisation visits at least one AEFI was reported. There were no differences in frequency or type of AEFI between the three clinical subgroups. The recombinant, adjuvanted zoster vaccine Shingrix® was associated with the highest rate of local and systemic reactions. Monitoring post-licensure vaccine safety using the active SMS-based surveillance system SmartVax is feasible in Switzerland. We observed a high acceptance in the diverse study population, including healthcare workers and IMID patients. High response rates in the elderly and reliable monitoring almost in real-time make SmartVax a promising tool for COVID-19 vaccine safety monitoring.

How were DTP-related adverse events reduced after the introduction of an acellular pertussis vaccine in Chile?

ABSTRACT Chile has a passive surveillance system of adverse events following immunization (AEFI) that allows monitoring and evaluating the safety profile of the vaccines administered. Between 2018 and 2019, the National Immunization Program (NIP) changed from a pentavalent whole-cell pertussis vaccine (wP) to a hexavalent (DTaP-IPV-HepB-Hib) acellular pertussis vaccine (aP) for children <2 years. Objectives To describe the trend in the frequency of adverse events (AE) records associated to pertussis component vaccines between January 1st, 2015 and June 30th, 2020 in infants younger than 2-years-old in Chile, by reviewing the records submitted to the AEFI NIP, stratified by DTP-vaccine type, wP or aP. Materials and methods This was a retrospective observational study including all AEFI records of DTP (either aP or wP)-containing vaccines in the described sample. A descriptive analysis was performed according to vaccine type and AEFI, using MedDRA terminology. Results The total number of AEFI reports was 1,697: 815 corresponding to wP vaccines, 417 to aP vaccines, and 465 with unknown type. The reporting rates for the years 2015 to 2020 were 40.1, 56.2, 37.1, 24.7, 19.1, and 12.2 per 100,000 doses administered, respectively. The most reported AEFI were injection site erythema (42.9%), pyrexia (35.7%), and pain at the injection site (29.2%). Among all cases, 5.8% were SAEs (n = 98), 5.9% were SAEs for wP vaccines (n = 48) and 5.3% were for aP vaccines (n = 22). Discussion A significant decrease in AEFI reports was observed as of 2018, the year that the DTaP-IPV-HepB-Hib was introduced in the NIP.