Vaccine hesitancy among 0–6-year-olds’ guardians in Chongqing: a cross-sectional survey revealing how immunization program managers’ robust comprehensive capacity for adverse events following immunization (AEFI) management mitigates hesitancy

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.

Willingness to receive a vaccine is influenced by adverse events following immunisation experienced by others.

Objective To evaluate the safety of national immunization program (NIP) vaccines and non-NIP vaccines in Fujian Province from 2011 to 2015. Methods The adverse events following immunization (AEFI) case information reported in Fujian Province from 2011 to 2015 was collected from the National AEFI Information Management System and vaccination data of NIP vaccines (11 species) and non-NIP vaccines (19 species) in the same period in Fujian Province were collected from the National Immunization Program Information Management System. The collected monitoring data were descriptively analyzed. The total and severe AEFI reporting rates and their 95% confidence intervals (CI) were calculated. Results From 2011 to 2015, a total of 70 976 300 doses of vaccines were inoculated in Fujian Province and a total of 8 987 cases of AEFI were reported, including 192 cases (2.14%) of severe AEFI. The incidence (95%CI) of reported AEFI was 12.66 (12.40-12.93) per 100 000 doses and the incidence (95%CI) of reported severe AEFI was 2.71 (2.34-3.12) per one million doses. A total of 55 702 100 doses of NIP vaccines were inoculated and 7 347 cases of AEFI were reported, of which 138 (1.88%) were severe AEFI cases. The incidence (95%CI) of reported AEFI was 13.19 (12.89-1.49) per 100 000 doses of NIP vaccines and the incidence (95%CI) of reported severe AEFI was 2.48 (2.08-2.93) per one million doses. Among the 11 NIP vaccines, the incidence (95%CI) of reported AEFI ranged from 0.95 (0.88-1.13) per 100 000 doses to 43.71 (40.72-46.75) per 100 000 doses and the incidence (95%CI) of reported severe AEFI ranged from 1.04 (0.32-1.76) per one million doses to 6.41 (2.78-10.04) per one million doses. A total of 15 271 600 doses of non-NIP vaccines were inoculated and 1 640 cases of AEFI were reported, of which 54 (3.54%) were severe AEFI cases. The total incidence (95%CI) of reported AEFI was 10.74 (10.23-11.27) per 100 000 doses and the incidence (95%CI) of reported severe AEFI was 3.54 (2.66-4.61) per one million doses. Among the 19 non-NIP vaccines, the incidence (95%CI) of reported AEFI ranged from 2.06 (0.38-3.71) per 100 000 doses to 45.22 (35.29-55.10) per 100 000 doses and the incidence (95%CI) of reported severe AEFI ranged from 0.52 (0-1.53) per one million doses to 20.89 (0-44.51) per one million doses. Conclusion From 2011 to 2015, the incidences of reported AEFI and severe AEFI for NIP and non-NIP vaccines circulated in Fujian Province were low, which had good safety. Key words: Vaccines; Vaccination; Immunization programs; Drug-related side effects and adverse reactions; Adverse drug reaction reporting systems

Background: Adverse events following immunization (AEFI) are a common occurrence in children after vaccination and can lead to loss of trust in the immunization program. Fear of AEFIs is a major factor implicated in ‘Vaccine Hesitancy’ as seen in countries with high vaccination coverage and low burden of vaccine preventable diseases. The study aimed at assessing the knowledge, attitudes and practices of mothers regarding AEFI and its impact on vaccination of their childrenMethods: A descriptive, cross sectional survey was conducted at the immunization clinic of a tertiary care hospital of western India. Mothers attending the immunization clinic were interviewed using a validated questionnaire. A sample size of 221 was derived based on the incidence of common AEFIs.Results: Awareness of AEFI was present in 86.4% participants while only 28% mothers confirmed that information regarding AEFIs was given to them at the time of immunization. Though awareness of minor side effects like fever (98%) and local reaction (85%) was good, less than 15% of the mothers were aware of serious AEFIs such as seizures and anaphylaxis. Only 66% mothers indicated that they would first consult their doctor in case of an adverse effect. Knowledge regarding true contraindications to vaccination was poor.Conclusions: Awareness of the possibility of AEFI was good and trust in immunization as a vital health intervention was intact. Awareness about serious AEFIs which necessitate prompt management was inadequate while that for minor side effects was satisfactory. Healthcare seeking behavior of mothers to serious AEFIs was appropriate.

Introduction: Amidst a rapid outbreak of COVID-19, ChAdOx1 nCoV-19 vaccine was initially administered to health care workers in Sri Lanka.Objective: The aim of this study was to investigate adverse events following immunization (AEFI) after the first dose of ChAdOx1 nCoV-19 vaccine in a group of Sri Lankan medical officers from 5th February to 7th March 2021.Methods: A retrospective survey was conducted using a pretested Google form questionnaire designed to gather demographic data, medical history, AEFI and their management. The questionnaire was shared among a convenience sample of medical officers through online apps (Facebook, Imo, Viber, WhatsApp). Responses to the questionnaire were collected and the quantitative and categorical data and their associations were analyzed statistically.Results: Of 836 participants (male/female ratio = 0.92; mean age = 39.6±7.9 years), the majority, 738 (88.3%) experienced AEFI. Commonest AEFI were body ache (80.7%), lethargy (76.1%), local site reactions (72.4%) fever (70.1%), chills (68.7%) and headache (61.5%). The most severe AEFI was body ache (35.6%). The mean time of onset of AEFI was 11.3±7.5 hrs. AEFI lasted for a mean duration of 36.3±24.3 hrs. Occurrence of AEFI was significantly associated with age and, individuals below 40 years were more likely to experience AEFI (Pearson Chi-Square =5.13; P=0.02). Moderate to severe AEFI was also significantly associated with age where a high proportion of younger individuals (≤40 years) experienced moderate to severe AEFI (Pearson Chi-Square 5.31, P=0.02). A proportion of females (80.7%) had AEFI. The occurrence of AEFI was significantly associated with the females (Pearson Chi-Square 10.34, P=0.01). A significant association between poor physical exercise and the incidence of AEFI (Pearson Chi-Square 11.15, P=0.004) was also observed. Those who had no regular exercise (79%) were more prone to get AEFI than those who had regular exercise (72.5%). Paracetamol was used prophylactically by 56.1% vaccinees prior to vaccination. Paracetamol was taken by 52.8% vaccinees (1g, 6-8 hourly for 2-3 days) therapeutically for AEFI as self-medication. However, 4 (0.005%) sought medical advice on further management and 7 (0.008%) got hospitalized.Conclusions: A high incidence (88%) of AEFI was observed in our study population. The commonest AEFI were body ache, lethargy, local site reactions, fever, chills and headache, while the most severe AEFI was body ache. AEFI associated in ChAdOx1 nCoV-19 vaccine lasted about 1-2 days. Occurrence of AEFI was significantly associated with females below 40 years and with low physical exercise. The majority took self medication with paracetamol either prophylactically or therapeutically. Medical consultation and hospitalization for AEFI were low. AEFI of ChAdOx1 nCoV-19 vaccine was observed to be tolerable and responded to self medication with paracetamol. Surveillance studies on AEFI are feasible using online apps.

Background: Vaccine against coronavirus disease 2019 (COVID-19) was rolled out in India to prevent the infection caused by severe acute respiratory syndrome coronavirus 2. We aimed at investigating the adverse events following immunization (AEFI) associated with the first dose of Covishield (ChAdOx1 nCoV-19) vaccine in the elderly population (60 and above). Methodology: An observational study, conducted among 463 vaccinated individuals at multiple community health centers in Jaipur, of AEFIs associated with the first dose of Covishield vaccine. We investigated these AEFIs through telephonic interviews, using pharmacovigilance per forma provided from the Indian Pharmacopoeia Commission, Ghaziabad. Results: Four hundred and sixty-three people responded to the telephone survey. About 7.7% (36/463) of the respondents experienced AEFIs. Of these, commonly reported systemic AEFI were fever (47.2%), fatigue (38.8%), dizziness (5.5%), and diarrhea (2.7%), and local AEFI were injection site soreness (27.7%) and itching with rash (2.7%) AEFI reported in the age group (60–70) was higher (8.7%, 26/297) than those above 70 (6.2%, 10/166). Females (9.9%, 20/202) were associated with higher AEFI than males (6.1%, 16/261). More than one-third (43.8%, 203/463, P = 0.001) were hesitant before vaccination. Respondents in the age group of 60–70 years (55.2%, 164/297) were more hesitant than those above 70 (23.4%, 39/166). There is no association between gender and AEFI status and age group and respondent's AEFI. Conclusion: Only 7.7% of the respondents experienced AEFIs associated with ChAdOx1 nCoV-19, though all were mild and self-limiting. There were no serious events requiring hospitalization, and most AEFIs improved within few days. Vaccine hesitancy among 43.8% of the respondents could be attributed to the unscientific information on social media.

Adverse Events Following Immunization (AEFI) have significant implications for public health, potentially leading to decreased immunization rates and vaccine hesitancy. Understanding the characteristics and outcomes of children experiencing AEFI is crucial for effective intervention strategies and informed decision-making. This study aimed to describe the diverse range of AEFI presentations, identify common referral sources and assess factors influencing vaccination uptake following specialist consultation. A single-center retrospective cohort study was conducted from 2019 to 2022, analyzing AEFI data from 191 children referred to a Specialist Immunization Service (SIS) at an Australian pediatric health service. Demographic data, referral details, vaccination history, and AEFI types were considered. Statistical analyses, including univariate and multivariate models, were employed to predict vaccination outcomes post-SIS consultation. The median age of children referred was 2 years. General practitioners were the major referral source (68%). Urticarial rash was the most prevalent AEFI referred (29%). Pneumococcal conjugate vaccine was the most implicated vaccine (38%). The majority (69%) were successfully vaccinated following SIS consultation with 3% experiencing a subsequent AEFI (all mild). Older age is found to be associated with less likelihood for vaccination (odds ratio = 0.93, 95% confidence interval: 0.88-0.99, P = 0.027). Formal reporting of AEFI was low (26%). Severe adverse events, including anaphylaxis, were rare, and a SIS played an important role in vaccinating children following AEFI. Vaccination following urticarial rash is likely safe, and options such as a drop-in immunization center in a hospital setting may reduce delay to the next dose in scheduled vaccinations following AEFI. AEFI reporting needs to be promoted, and a patient-initiated reporting system may enhance this.

In Quebec, COVID-19 vaccine uptake among adults was high for the first two doses but decreased for the subsequent booster doses. This study assesses the relationships between attitudes towards vaccination and self-reported experience and severity of adverse events following immunization (AEFIs). A web survey of Quebec adults who received at least one dose of the COVID-19 vaccine was conducted in September 2023. Participants share their level of vaccine hesitancy before vaccination and their experience with AEFIs after receiving a dose. Participants were asked to note the severity of the symptoms they believed were due to vaccination. Intention to receive other vaccines in the future was questioned. Two coders performed a qualitative content analysis on reported AEFIs (N=3808). Descriptive and multivariate logistic regression analyses were performed. Among the 8419 vaccinated respondents, 46.7% reported having experienced AEFIs. Fatigue or malaise (20.7%), injection site disorder (17.3%), musculoskeletal pain (11.2%), headache (11.0%), and fever (10.6%) were the most commonly reported, respectively. Respondents who were very hesitant before the COVID-19 vaccine reported more frequently having a severe AEFI compared to those who were not hesitant (25.0% vs 3.4% =, p<0.001). This affirmation stays true when all severity of adverse events are considered (68.7% vs 36.9%) (p<0.001). Younger age (aOR=0.98), being a female (aOR=1.31), a higher education level (University degree aOR=1.56 vs high school or less), being vaccine-hesitant in general (aOR=1.69 vs non or less hesitant) were significantly associated (p<0.001) with self-reported AEFIs in multivariate analysis. Self-reported AEFIs that prevented doing activities (aOR=4.87) and being vaccine-hesitant in general (aOR=4.94) were significantly associated with reduced intention to receive other vaccines in the future. Vaccine hesitancy could influence self-reported AEFIs and their perceived severity. Transparent and tailored communication explaining AEFIs while emphasizing strategies to mitigate these effects could helpful. Our findings also have implications for pharmacovigilance. 301 mots.

Parental vaccine hesitancy (VH) threatens childhood immunization and may improve vaccination coverage. This study aimed to investigate parental VH factors in childhood immunization in Southern Italy, focusing on sociodemographic factors, adverse events following immunization (AEFIs), and participants perceptions of child vulnerability and health factors. A cross-sectional electronic survey was conducted between September 2024 and January 2025 among parents/caregivers of children and adolescents in Sicily and Calabria. The survey included the Parent Attitudes about Childhood Vaccines Questionnaire (PACV-5), the Child Vulnerability Scale (CVS), and the Parent Health Locus of Control Scales (PHLoC). Multivariable logistic regression models were used to identify independent factors associated with VH reporting adjusted Odds Ratio (aOR) with corresponding 95% confidence intervals (CIs). In this facility-based sample, 44.5% screened positive for VH in childhood immunization. Prior vaccine refusal (aOR 3.56; 95% CI: 2.09-6.06), experiencing an AEFI after the last vaccination (aOR: 2.00; 95% CI: 1.09-3.67), including more than one AEFI (aOR: 1.88; 95% CI: 1.14-3.11), or changes in hesitancy following an AEFI (aOR 5.31; 95% CI: 2.60-10.90) were associated with higher VH. PHLoC Destiny (aOR 1.43; 95% CI: 1.21-1.69) and Divine (aOR 1.14; 95% CI: 1.01-1.30) were associated with higher VH, whereas PHLoC Professionals with lower VH (aOR 0.72; 95% CI: 0.60-0.86). Parental VH was associated with safety concerns and the influence of imponderable PHLoC factors, while trust in healthcare professionals was linked to lower VH, underscoring the need for targeted, empowerment-based communication strategies to improve vaccination confidence.

Background: The concern for adverse events following immunization (AEFI) and anti-vaccination movements that lacked scientific evidence-based supports may reduce vaccine uptake in the general population. Thus, the aims of the present study were to characterize AEFI in general population (all age groups), in terms of frequency, preventability, and seriousness and to define predictors of their seriousness in children.Methods: A retrospective study was performed on suspected AEFI reports for children and adults who received any form of vaccinations, collected in Tuscany, Italy, between 1 January and 31 December 2017. Patients’ characteristics, suspected vaccines, and AEFI description were collected. Causality and preventability were assessed using WHO and Schumock and Thornton algorithms, respectively. Logistic regression was used to estimate the reporting odds ratios of potential predictors of AEFI seriousness in children.Results: A total of 223 suspected AEFI reports were collected, and the majority of them were defined as non-serious (76.7%). Reports were mostly related to one vaccine, and to a median of two to five strains/toxoids. The total number of simultaneously administered strains/toxoids and the presence of allergens did not correlate with AEFI seriousness. Considering vaccines with a high number of administered doses (≥60,000 doses), the rates estimated for serious AEFI reports were always very low, ranging between 0.01 and 0.2/1,000 doses. Twenty-four vaccines (8,993 doses) were not related to any AEFI.Conclusion: Results of present study showed that AEFI were very rare; the vast majority of them was non-serious and, despite the claims of anti-vaccination movements, the simultaneous administration of vaccines was safe and did not influence the risk of reporting a serious AEFI, particularly in children.

COVID-19 is declared a global pandemic by the WHO; vaccines were the need of the hour to reduce mortality and return to some form of normal life. The Indian government provides two vaccines as per the program; ChAdOx1 nCoV-19 and BBV152; Bharat Biotech COVID-19 vaccine. However, vaccine hesitancy is a major public health concern. To evaluate the adverse events following immunization (AEFIs) after COVID-19 vaccination. The safety profile of ChAdOx1 nCoV-19 and BBV152 vaccine was also studied. This was a large-scale, cross-sectional survey. Beneficiaries who had their vaccination in the past 2 weeks were sent an online survey performa regarding AEFIs after COVID-19 vaccine. Out of 2311 participants, 58% received ChAdOx1-nCoV-19 and 42% received BBV152 COVID-19 vaccine, with the mean ± standard deviation age (years) of 36.3 ± 14.5 and 16.9 ± 4.07, respectively. The previous history of COVID-19 infection was reported in 7% of the participants. In the ChAdOx1-nCoV-19 group, 85.3% participants reported at least one adverse reaction, with pain at site being the most common, followed by fever, fatigue, and feeling of unwellness. In the BBV152 group, 17% reported adverse reaction, with pain site being the most common, followed by tenderness, fatigue, and feeling of unwellness. In the BBV152 group, a significant positive association was observed between AEFIs and age. In the ChAdOx1-nCoV-19 group, age was marginally associated with AEFIs. AEFIs were more after first dose (121 vs. 43, P < 0.001, adjusted odds ratio (OR) =3.39 [95% confidence interval [CI]: 2.24-5.11], P < 0.001) among elderly (adjusted OR = 0.60, 95% CI: 0.36-0.99, P = 0.047) and women (721 vs. 423, P = 0.001, adjusted OR = 1.68 [95% CI: 1.24-2.29], P = 0.001). Our study observed that both ChAdOx1 nCoV-19 and BBV152 have a favorable safety profile without serious AEFIs in any of the beneficiaries.

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.

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

Assessment of the surveillance system for adverse events following immunisation in the Gaza Strip: a cross-sectional study

A Prospective Observational Study on BBV152 Coronavirus Vaccine Use in Adolescents and Comparison with Adults: Interim Results of the First Real-World Safety Analysis