Vaccine Adverse Event Research Articles

Factors influencing adverse events following COVID-19 vaccination

ABSTRACT Various novel platform technologies have been used for the development of COVID-19 vaccines. In this nested cohort study among healthcare workers in Australia and Brazil who received three different COVID-19-specific vaccines, we (a) evaluated the incidence of adverse events following immunization (AEFI); (b) compared AEFI by vaccine type, dose and country; (c) identified factors influencing the incidence of AEFI; and (d) assessed the association between reactogenicity and vaccine anti-spike IgG antibody responses. Of 1302 participants who received homologous 2-dose regimens of ChAdOx1-S (Oxford-AstraZeneca), BNT162b2 (Pfizer-BioNTech) or CoronaVac (Sinovac), 1219 (94%) completed vaccine reaction questionnaires. Following the first vaccine dose, the incidence of any systemic reaction was higher in ChAdOx1-S recipients (374/806, 46%) compared with BNT162b2 (55/151, 36%; p = 0.02) or CoronaVac (26/262, 10%; p < 0.001) recipients. After the second vaccine dose, the incidence of any systemic reaction was higher in BNT162b2 recipients (66/151, 44%) compared with ChAdOx1-S (164/806, 20%; p < 0.001) or CoronaVac (23/262, 9%; p < 0.001) recipients. AEFI risk was higher in younger participants, females, participants in Australia, and varied by vaccine type and dose. Prior COVID-19 did not impact the risk of AEFI. Participants in Australia compared with Brazil reported a higher incidence of any local reaction (170/231, 74% vs 222/726, 31%, p < 0.001) and any systemic reaction (171/231, 74% vs 328/726, 45%, p < 0.001), regardless of vaccine type. Following a primary course of ChAdOx1-S or CoronaVac vaccination, participants who did not report AEFI seroconverted at a similar rate to those who reported local or systemic reactions. In conclusion, we found that the incidence of AEFI was influenced by participant age and COVID-19 vaccine type, and differed between participants in Australia and Brazil.

Acoustic Detection of Vaccine Reactions in Hens for Assessing Anti-Inflammatory Product Efficacy

Acoustic studies on poultry show that chicken vocalizations can be a real-time indicator of the health conditions of the birds and can improve animal welfare and farm management. In this study, hens vaccinated against infectious laryngotracheitis (ILT) were acoustically recorded for 3 days before vaccine administration (pre-reaction period) and also from vaccination onwards, with the first 5 days being identified as the “reaction period” and the 5 following days as “post reaction”. The raw audio was pre-processed to isolate hen calls and the 13 Mel-frequency cepstral coefficients; then, the spectral centroid and the number of vocalizations were extracted to build the acoustic dataset. The experiment was carried out on the same farm but in two different houses. The hens from one house were assigned to the control group, without administration of the anti-inflammatory product, and the other formed the treatment group. Both acoustic data sets were recorded and processed in the same way. The control group was used to acoustically model the animal reaction to the vaccine and we automatically detected the hens’ vaccine reactions and side effects through acoustics. From Scikit-Learn algorithms, Gaussian Naive Bayes was the best performing model, with a balanced accuracy of 80% for modeling the reactions and non-reactions caused by ILT in the control group. Furthermore, the importance of algorithm permutation highlighted that the centroid and MFCC4 were the most important features in acoustically detecting the ILT vaccine reaction. The fitted Gaussian Naive Bayes model allowed us to evaluate the treatment group to determine if the vocalizations after vaccine administration were detected as non-reactions, due to the anti-inflammatory product’s effectiveness. Of the sample, 99% of vocalizations were classified as non-reactions, due to the anti-inflammatory properties of the product, which reduced vaccine reactions and side effects. The non-invasive detection of hens’ responses to vaccination to prevent respiratory problems in hens described in this paper is an innovative method of measuring and detecting avian welfare.

Sequence Labelling with 2 Level Segregation (SL2LS): A framework to extract COVID-19 vaccine adverse drug reactions from Twitter data

Social media data is an opportunistic resource for post-marketing surveillance of COVID-19 (Coronavirus disease of 2019) vaccines. However, the usage of the term Adverse Drug Reaction (ADR) in different contexts, which do not refer to adverse reactions to given vaccines, poses a great challenge for existing ADR extraction techniques. In the present work, a framework titled “Sequence Labelling with 2 Level Segregation” (SL2LS) has been proposed to extract adverse reactions of COVID-19 vaccines from Twitter data. It handles the mentioned challenge by deploying a Bidirectional Long Short-Term Memory (Bi-LSTM) based two-level classification model to segregate the tweets containing ADR terms that represent adverse reactions of vaccines from the tweets that comprise ADR terms which are not referring to adverse reactions of vaccines based on the context of ADR term usage and then employ domain-specific pre-trained Bidirectional Encoder Representations from Transformers for Biomedical Text Mining (BioBERT) sequence labelling model for extracting vaccine linked ADRs from segregated tweets. The proposed framework has been applied to Covaxin and Covishield COVID-19 vaccine data collected from Twitter and annotated with the help of a domain expert. It achieved the highest precision, recall and F1-score of 95.46%, 93.2% and 94.33%, respectively, in comparison to other state-of-the-art techniques. The validation of detected top 20 frequent ADRs of the two vaccines with official surveillance reports resulted in 19 verified ADRs for Covaxin and all 20 verified ADRs for Covishield and one unverified ADR “Blood Clot” for Covaxin which is a valuable lead for medical experts for further exploration. Further analysis shows that the two vaccines share some common ADRs viz. “Discomfort”, “Fever”, “Pain”, “Headache” and “Fatigue” and “Discomfort” and “Fever” are the most frequent ADRs associated with Covaxin and Covishield vaccines, respectively.

Risk of myocarditis after three doses of COVID-19 mRNA vaccines in the United States, 2020-2022: A self-controlled case series study.

Myocarditis is a recognized safety concern following COVID-19 mRNA vaccination. However, there is limited research quantifying the risk associated with the third dose or comparing the risk between the three doses. The US Vaccine Adverse Event Reporting System (VAERS) is a passive surveillance system that monitors rare adverse events after US-licensed vaccination. However, studies analyzing VAERS data have often faced criticism for underreporting cases and lacking a control group to assess the increase in baseline risk. The temporal association between myocarditis onset and COVID-19 vaccination was studied. To overcome limitations, a novel modified self-controlled case series method was employed, explicitly modeling the case reporting process in VAERS data. We found an increased risk of myocarditis during the 1- to 3-day period following the second and third doses of both the BNT162b2 vaccine and the mRNA-1273 vaccine. Following the second dose, the relative incidence (RI) was 4.89 (95% confidence interval (CI), 2.39-10.08) for the BNT162b2 vaccine and 2.86 (95% CI: 1.18-7.03) for the mRNA-1273 vaccine. Similarly, following the third dose, the RI was 9.04 (95% CI: 2.79-40.99) for the BNT162b2 vaccine and 4.71 (95% CI: 1.42-19.09) for the mRNA-1273 vaccine. No significant increase in risk was observed during other periods. Notably, our analysis also identified a similar increased risk of myocarditis among individuals aged below 30. These findings raise safety concerns regarding COVID-19 mRNA vaccines, provide insights into the quantification of myocarditis risk at different postvaccination periods, and offer a novel approach to interpreting passive surveillance system data.

Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome following vaccination: analysis of the VAERS database and systematic review.

This study aimed to analyze the Vaccine Adverse Event Reporting System (VAERS) database and systematically review the literature to provide a comprehensive analysis of reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) secondary to vaccination. The authors analyzed the VAERS database and conducted a systematic review following PRISMA guidelines. The inclusion criteria for VAERS data were a score of ≥3 on the RCVS2 score and/or radiographic findings consistent with the diagnosis of RCVS or PRES. The systematic review was registered with PROSPERO. Our combined data set included 29 cases (9 RCVS and 20 PRES). Most cases were women (72.4%) with a mean age of 50.7 years (SD 19.4 years). Most cases were associated with COVID-19 mRNA vaccines (58.6% Moderna, 20.7% Pfizer). Hypertension (37.9%), hyperlipidemia (13.7%), chronic kidney disease (CKD) (10.3%), and end-stage renal disease (6.8%) were common comorbidities. Furthermore, 20.6% (6/29) of cases were on immunosuppression therapy for various reasons. The mean time to symptom onset was 10.49 days after vaccination (SD 18.60), and the mean duration of hospitalization was 7.42 days (SD 5.94). The symptoms reported the most frequently were headache (41.3%), elevated blood pressure (31.0%), and emesis (17.2%). Typical radiographic findings included T2/FLAIR hyperintensities affecting the parieto-occipital lobes, indicative of vasogenic and/or cytotoxic edema. This study provides a comprehensive analysis of postvaccine RCVS and PRES. Both disease states were seen most often in those with pre-existing risk factors such as female sex, age over 50, hypertension, renal disease, and immunosuppression. Vaccines and their associated immune response may cause endothelial dysfunction leading to cerebral vasospasm and loss of cerebral autoregulation. However, further research is required to understand the underlying pathophysiological mechanisms. Despite the associations found, the absolute risk of these syndromes remains extremely low compared to the immense benefits of vaccination.

The Impact of the COVID-19 Pandemic on the Incidence of Herpes Zoster: A Narrative Literature Review.

Coronavirus disease 2019 (COVID-19) has had a broad impact on health services and health outcomes. During the pandemic, there were numerous reports of herpes zoster (HZ) in people with COVID-19 and in COVID-19 vaccine recipients. The aim of this review is to elucidate the global effects of the COVID-19 pandemic on HZ. It is postulated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces an immunosuppressive state that favours varicella zoster virus (VZV) reactivation. Three large cohort studies (a multinational study and studies from the USA and Spain) that excluded individuals vaccinated against HZ reported significantly increased risk of HZ following COVID-19 infection, especially in people aged ≥ 50years. In contrast, a large study from Israel that did not consider HZ vaccination status reported no such increase. Cases of HZ following COVID-19 vaccination have been reported and may be the result of attenuated cell-mediated immunity. This phenomenon appears to vary by vaccine type. Some (but not all) large analyses have reported a significant positive relationship between receipt of mRNA vaccines for COVID-19 and development of HZ. These include analyses of health records databases in Israel and Hong Kong and of spontaneous case reports in the US Vaccine Adverse Event Reporting System (VAERS) database. Routine vaccinations, including shingles vaccine programmes, were disrupted by the COVID-19 pandemic. It is estimated that missed shingles vaccinations may have resulted in 63,117 avoidable HZ cases in the USA. Now that the World Health Organization has declared an end to the COVID-19 pandemic as a health emergency and routine vaccination services have resumed, there is a need to increase awareness of HZ and HZ vaccination.Graphical abstract available for this article.

Safety of Simultaneous Administration of Bivalent mRNA COVID-19 and Influenza Vaccines in the Vaccine Adverse Event Reporting System (VAERS).

Bivalent mRNA coronavirus disease 2019 (COVID-19) vaccines may be simultaneously administered with other recommended vaccines, including seasonal influenza vaccines. However, few studies have evaluated the safety of co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. The aim was to describe reports to the Vaccine Adverse Event Reporting System (VAERS) after co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. We searched the VAERS database for reports of adverse events (AEs) following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines during the period ofSeptember 1, 2022-March 31, 2023. We assessed the characteristics of these reports and described the most frequently reported AEs. Clinicians reviewed available medical records for reports of serious AEs and adverse events of special interest (AESI). During the period of1 September 2022 through 31 March 2023, VAERS received 3689 reports of AEs following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. The median age of vaccinees was 59 years (interquartile range 39, 70 years); 342 reports (9.3%) were classified as serious. The most common AEs among non-serious reports were severe-acute-respiratory-syndrome-related coronavirus (SARS-CoV-2) infection (785, 23.5%), cough (592, 17.7%), and fatigue (568, 17.0%). The most common AEs among serious reports were Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection (88, 25.7%), dyspnea (81, 23.7%), and condition aggravated (55, 16.1%). Reports of AEs following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines did not reveal any unusualorunexpected patterns of AEs. Increased reporting of certain events (e.g., COVID-19) was expected due to Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) reporting requirements. CDC and FDA will continue to monitor the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines.

Misinformation and the Vaccine Adverse Event Reporting System

This Viewpoint posits that to improve public understanding of the system, the Vaccine Adverse Event Reporting System (VAERS) could use a more accurate name, well-defined guidance about the reporting system’s nature and use, and comprehensible information about an event’s verification status.

The Impact of the Emotional Disposition of Healthcare Workers on the Expression of Adverse Events after Primary Vaccination against SARS-CoV-2.

Background and Objectives: Vaccination is one means of SARS-CoV-2 prevention and control. However, despite the effectiveness of vaccination, adverse reactions continue to require vigilance and monitoring. The researchers emphasize the possibility that some of the reported side effects may be psychological in origin. Based on this hypothesis, the main goal of this study was to evaluate the emotional dispositions of healthcare workers who experienced emotions before vaccination and adverse reactions after vaccination. Materials and Methods: This study was conducted between February and May 2021 in the Kaunas Clinics of the University of Health Sciences. A total of 2117 employees of the clinic departments who were vaccinated with two doses of the Pfizer-BioNTech vaccine participated in this study. Statistical analysis was performed on the data using IBM SPSS Statistics®. Results: Most participants (74.5%) experienced systemic (including local) adverse events; 16.5% experienced only local adverse events, and 9.1% experienced no adverse events. The frequency of systemic (including local) adverse events reduced with increasing age (p < 0.05). The main emotions that participants experienced before vaccination were anxiety (37.88%) and happiness (39.02%). Systemic (including local) adverse events occurred 1.26 times more frequently in women than men (77.44% vs. 61.6%, p < 0.05), while local adverse events occurred 1.4 times more often in male participants than in female participants (21.39% vs. 15.27%, p < 0.05). Among the respondents who did not experience adverse events, the most common emotion felt was happiness (25.5%), and most of the participants who experienced systemic (including local) adverse events felt anxiety (42.6%). Conclusions: The information about vaccination and potential adverse events should be targeted at younger persons. It is recommended that women, more than men, should receive professional counseling from psychologists or psychotherapists. The public dissemination of positive messages about the benefits and safety of vaccines prior to a vaccination campaign may alleviate the tension or anxiety felt regarding potential adverse events. Healthcare specialists-both those who work directly with vaccines and those who do not-should maintain a positive psychological attitude towards vaccination, as this can increase patient satisfaction with the benefits of vaccines.

Administration of the GSK Respiratory Syncytial Virus Vaccine to Pregnant Persons in Error.

The GSK and Pfizer respiratory syncytial virus (RSV) vaccines are both indicated for adults aged 60 years and older, but only the Pfizer product is approved for use in pregnancy to prevent RSV-associated lower respiratory tract disease in infants aged younger than 6 months. To assess for vaccine administration errors (ie, administration of the GSK RSV vaccine to pregnant persons) VAERS (Vaccine Adverse Event Reporting System), a U.S. passive reporting system, was searched for the time period from August 2023 to January 2024. A total of 113 reports of these administration errors were identified. Most reports (103, 91.2%) did not describe an adverse event. These administration errors are preventable with proper education and training and other preventive measures.

Real-world data of China: Analysis of HPV vaccine coverage and post-vaccination adverse reaction monitoring in Western Chinese provinces from 2018 to 2021

ABSTRACT To investigate the HPV vaccine coverage and post-vaccination adverse reactions in Gansu Province, Western China, from 2018 to 2021. Data on suspected adverse reactions to HPV vaccines were collected from the Chinese Vaccine Adverse Event Following Immunization (AEFI). Estimate the incidence rates of Common Adverse Reaction and Rare Adverse Reaction. HPV vaccine coverage among females in different age groups was calculated using data from the Gansu Provincial Immunization Information Platform. The first-dose HPV vaccine coverage rate among females aged 9 to 45 was 2.02%, with the lowest rate of less than 1% observed in females aged 9 to 14. From 2018 to 2021, the incidence rates of Common Adverse Reaction and Rare Adverse Reaction reported in females after HPV vaccination were 11.82 and 0.39 per 100,000 doses, respectively. Common Adverse Reaction included fever (5.52 per 100,000 doses), local redness and swelling (3.33 per 100,000 doses), fatigue (3.15 per 100,000 doses), headache (2.76 per 100,000 doses), as well as local induration and nausea/vomiting (1.97 per 100,000 doses). Adverse reactions mainly occurred within 1 day after vaccination, followed by 1 to 3 days after vaccination. The HPV vaccine coverage rate among females aged 9 to 14 in Gansu Province is remarkably low, and there is an urgent need to enhance vaccine coverage. From 2018 to 2021, the incidence of Adverse reaction Following Immunization HPV vaccination fell within the expected range, indicating the vaccine’s safety profile.

(071) Just Another Vaccine – VAERS Analysis Compares Genitourinary Symptoms of the COVID-19 Vaccine and Other Commonly Administered Vaccines

Abstract Introduction There has been a concern in mainstream media about adverse effects of the COVID-19 vaccine including those on the genitourinary system. Objective Our objective was to evaluate the rate of patient-reported genitourinary symptoms after the COVID-19 vaccine. We hypothesized rates of genitourinary side effects was not different compared to other commonly used vaccines. Methods We queried the Vaccine Adverse Events Reporting System (VAERS) database for all genitourinary symptoms reported after receiving the COVID-19, influenza, shingles, and pneumonia vaccines. Symptoms were placed into one of five categories – lower urinary tract symptoms (LUTS), sexual side effects, infectious, hematuria, or other disorders of the penis/scrotum/testis. Rates of genitourinary symptoms were compared between the vaccines. Data collection occurred 7-8/2022. Results Out of 13,568,650 symptoms reported after the COVID-19 vaccine, 9,022 were genitourinary (0.066%). Genitourinary symptoms included LUTS (39.71%), infectious (32.38%), hematuria (17.42%), disorders of the penis/scrotum/testis (5.99%), and sexual side effects (4.50%). Rates of genitourinary symptoms after the COVID-19 vaccine was significantly lower than the influenza (0.128%) (Table 1) but higher than the shingles (0.030%) and pneumonia (0.037%) vaccines (Table 2). There was no significant differences in the penis/scrotum/testis symptoms category. Rates of sexual side effects were overall low after the COVID vaccine (0.0030%) and not significantly different to rates of sexual side effects after the influenza vaccine (0.0036%) but were higher than after the pneumonia and shingles vaccines. Conclusions Genitourinary symptoms from the COVID-19 vaccine are rare. The rate of side effects is lower than the influenza vaccine, and while sexual and overall side effects are higher than the pneumonia and shingles vaccines, these rates are overall very low and unlikely to be clinically significant. Disclosure No.

Pengaruh Efek Samping Imunisasi terhadap Tingkat Kecemasan Ibu Balita

An adverse event following immunization (AEFI) are medical case which related to vaccine reactions, injection reactions, pharmacological effects, procedural in failure, coincidences or undetermined causal relationships. AEFI are also defined as a medical event following an unintended immunization that results in hospitalization or extension of hospitalization, permanent or significant disability and death, and causes unrest. This study aims of this study was to find out immunization side effects on the anxiety level of mothers who has toddler in the Cakru Community Health Center working area located in Jember.The research method used quantitative with correlational techniques by sample size of 51 people, and using the Chi Square test for analyze.From identificated of immunization on toddler, that was found if most of respondents got of immunization effects about 38 respondents (74.5%) and most of them respondents had mild low anxiety about 26 respondents (51%). The results bye Chi-Square test, it was found it p value&lt;0.05, (p = 0.000) which was indicated, there was immunization side effects to anxiety level of mothers in the Cakru Health Center Work Area.Families and mothers are expected to participate health education about complete immunization and about the effects after getting immunization.

Safety signal detection with control of latent factors.

Postmarket drug safety database like vaccine adverse event reporting system (VAERS) collect thousands of spontaneous reports annually, with each report recording occurrences of any adverse events (AEs) and use of vaccines. We hope to identify signal vaccine-AE pairs, for which certain vaccines are statistically associated with certain adverse events (AE), using such data. Thus, the outcomes of interest are multiple AEs, which are binary outcomes and could be correlated because they might share certain latent factors; and the primary covariates are vaccines. Appropriately accounting for the complex correlation among AEs could improve the sensitivity and specificity of identifying signal vaccine-AE pairs. We propose a two-step approach in which we first estimate the shared latent factors among AEs using a working multivariate logistic regression model, and then use univariate logistic regression model to examine the vaccine-AE associations after controlling for the latent factors. Our simulation studies show that this approach outperforms current approaches in terms of sensitivity and specificity. We apply our approach in analyzing VAERS data and report our findings.

Ally, adversary, or arbitrator? The context-dependent role of eosinophils in vaccination for respiratory viruses and subsequent breakthrough infections.

Eosinophils are a critical type of immune cell and central players in type 2 immunity. Existing literature suggests that eosinophils also can play a role in host antiviral responses, typically type 1 immune events, against multiple respiratory viruses, both directly through release of antiviral mediators and indirectly through activation of other effector cell types. One way to prime host immune responses toward effective antiviral responses is through vaccination, where typically a type 1-skewed immunity is desirable in the context of intracellular pathogens like respiratory viruses. In the realm of breakthrough respiratory viral infection in vaccinated hosts, an event in which virus can still establish productive infection despite preexisting immunity, eosinophils are most prominently known for their link to vaccine-associated enhanced respiratory disease upon natural respiratory syncytial virus infection. This was observed in a pediatric cohort during the 1960s following vaccination with formalin-inactivated respiratory syncytial virus. More recent research has unveiled additional roles of the eosinophil in respiratory viral infection and breakthrough infection. The specific contribution of eosinophils to the quality of vaccine responses, vaccine efficacy, and antiviral responses to infection in vaccinated hosts remains largely unexplored, especially regarding their potential roles in protection. On the basis of current findings, we will speculate upon the suggested function of eosinophils and consider the many potential ways by which eosinophils may exert protective and pathological effects in breakthrough infections. We will also discuss how to balance vaccine efficacy with eosinophil-related risks, as well as the use of eosinophils and their products as potential biomarkers of vaccine efficacy or adverse events.

Improving large language models for clinical named entity recognition via prompt engineering.

The study highlights the potential of large language models, specifically GPT-3.5 and GPT-4, in processing complex clinical data and extracting meaningful information with minimal training data. By developing and refining prompt-based strategies, we can significantly enhance the models' performance, making them viable tools for clinical NER tasks and possibly reducing the reliance on extensive annotated datasets. This study quantifies the capabilities of GPT-3.5 and GPT-4 for clinical named entity recognition (NER) tasks and proposes task-specific prompts to improve their performance. We evaluated these models on 2 clinical NER tasks: (1) to extract medical problems, treatments, and tests from clinical notes in the MTSamples corpus, following the 2010 i2b2 concept extraction shared task, and (2) to identify nervous system disorder-related adverse events from safety reports in the vaccine adverse event reporting system (VAERS). To improve the GPT models' performance, we developed a clinical task-specific prompt framework that includes (1) baseline prompts with task description and format specification, (2) annotation guideline-based prompts, (3) error analysis-based instructions, and (4) annotated samples for few-shot learning. We assessed each prompt's effectiveness and compared the models to BioClinicalBERT. Using baseline prompts, GPT-3.5 and GPT-4 achieved relaxed F1 scores of 0.634, 0.804 for MTSamples and 0.301, 0.593 for VAERS. Additional prompt components consistently improved model performance. When all 4 components were used, GPT-3.5 and GPT-4 achieved relaxed F1 socres of 0.794, 0.861 for MTSamples and 0.676, 0.736 for VAERS, demonstrating the effectiveness of our prompt framework. Although these results trail BioClinicalBERT (F1 of 0.901 for the MTSamples dataset and 0.802 for the VAERS), it is very promising considering few training samples are needed. The study's findings suggest a promising direction in leveraging LLMs for clinical NER tasks. However, while the performance of GPT models improved with task-specific prompts, there's a need for further development and refinement. LLMs like GPT-4 show potential in achieving close performance to state-of-the-art models like BioClinicalBERT, but they still require careful prompt engineering and understanding of task-specific knowledge. The study also underscores the importance of evaluation schemas that accurately reflect the capabilities and performance of LLMs in clinical settings. While direct application of GPT models to clinical NER tasks falls short of optimal performance, our task-specific prompt framework, incorporating medical knowledge and training samples, significantly enhances GPT models' feasibility for potential clinical applications.

Vaccination coverage and adverse events following a reactive vaccination campaign against hepatitis E in Bentiu displaced persons camp, South Sudan.

Hepatitis E (HEV) genotypes 1 and 2 are the common cause of jaundice and acute viral hepatitis that can cause large-scale outbreaks. HEV infection is associated with adverse fetal outcomes and case fatality risks up to 31% among pregnant women. An efficacious three-dose recombinant vaccine (Hecolin) has been licensed in China since 2011 but until 2022, had not been used for outbreak response despite a 2015 WHO recommendation. The first ever mass vaccination campaign against hepatitis E in response to an outbreak was implemented in 2022 in Bentiu internally displaced persons camp in South Sudan targeting 27,000 residents 16-40 years old, including pregnant women. We conducted a vaccination coverage survey using simple random sampling from a sampling frame of all camp shelters following the third round of vaccination. For survey participants vaccinated in the third round in October, we asked about the onset of symptoms experienced within 72 hours of vaccination. During each of the three vaccination rounds, passive surveillance of adverse events following immunisation (AEFI) was put in place at vaccination sites and health facilities in Bentiu IDP camp. We surveyed 1,599 individuals and found that self-reported coverage with one or more dose was 86% (95% CI 84-88%), 73% (95% CI 70-75%) with two or more doses and 58% (95% CI 55-61%) with three doses. Vaccination coverage did not differ significantly by sex or age group. We found no significant difference in coverage of at least one dose between pregnant and non-pregnant women, although coverage of at least two and three doses was 8 and 14 percentage points lower in pregnant women. The most common reasons for non-vaccination were temporary absence or unavailability, reported by 60% of unvaccinated people. Passive AEFI surveillance captured few mild AEFI, and through the survey we found that 91 (7.6%) of the 1,195 individuals reporting to have been vaccinated in October 2022 reported new symptoms starting within 72 hours after vaccination, most commonly fever, headache or fatigue. We found a high coverage of at least one dose of the Hecolin vaccine following three rounds of vaccination, and no severe AEFI. The vaccine was well accepted and well tolerated in the Bentiu IDP camp community and should be considered for use in future outbreak response.

Ophthalmologic Complications in Coronavirus Disease 2019 Immunization: A National Vaccine Adverse Event Reporting System Analysis

In this Vaccine Adverse Event Reporting System disproportionality analysis, COVID-19 immunization was rarely and generally not significantly associated with ophthalmologic complications. However, some symptoms were positive on Janssen vaccination, suggesting a need for continued investigation.

The impact of COVID-19 vaccine reactions on secondary vaccine hesitancy

BackgroundPrimary and booster vaccinations are critical for mitigating COVID-19 transmission, morbidity, and mortality. Future booster vaccine campaigns rely on an increased understanding of vaccine hesitancy. ObjectiveTo evaluate self-reported allergic and skin vaccine reactions as factors potentially associated with vaccine hesitancy in a nationwide vaccine allergy registry. MethodsResponses to survey questions concerning COVID-19 vaccine perceptions, coded from free text by 2 independent reviewers. Multivariable logistic regression models were used to determine the association between changed negative perception and respondent demographics, vaccination history, and reaction characteristics. ResultsA total of 993 individuals (median of 46 years [IQR, 36-59], 88% female, 82% White) self-reported reactions to COVID-19 vaccination. Reactions included the following: delayed large local skin reaction (40%), hives/urticaria (32%), immediate large local skin reaction (3%), swelling (3%), anaphylaxis (2%), and other or unspecified (20%). Most respondents were initially unconcerned about the safety of COVID-19 vaccines (56%). After reactions, 401 of 993 (40%) report negative change in perception of vaccination, with more than half of these respondents (n = 211, 53%) citing their reasoning as a negative experience with adverse effects. Of 102 individuals asked about future vaccination, 79 (77%) indicated that they were unlikely or very unlikely to receive future COVID-19 vaccinations. Increased negative perception after reaction was associated with younger age, later COVID-19 vaccination dose number, and reaction type. ConclusionOur findings reveal that an individual's experience with allergic or cutaneous adverse effects after COVID-19 vaccination affects attitudes and decision-making regarding future vaccination, even in initially non-hesitant individuals. Further investigation of secondary vaccine hesitancy is necessary for adapting public health messaging to this important population.

Leveraging COVID-19 Vaccine Safety Monitoring in Ethiopia and Pakistan to Enhance System-Wide Safety Surveillance.

The rapid development, introduction, and global uptake of COVID-19 vaccines required countries to have strong pharmacovigilance systems in place to monitor and address adverse events following immunization (AEFIs). These systems provide timely data on vaccine safety that support decisions about the potential risks of vaccine adverse events relative to the benefit of disease prevention. In Ethiopia, the monitoring system was limited by the lack of data being submitted through its passive surveillance system, delays in investigating serious adverse events and conducting causality assessments, and the lack of reporting to the World Health Organization (WHO) global database, VigiBase. In Pakistan, the pharmacovigilance system lacked reporting requirements and guidance documentation, regulatory policies were insufficient, and staff lacked the capacity to evaluate AEFI reports. Several interventions were implemented in both countries to improve pharmacovigilance systems and processes necessary to collect, analyze, and report AEFIs from health care facilities to the national level and facilitate the use of global and national electronic reporting tools. In addition, Pakistan improved the regulatory policy environment and engaged vaccine manufacturers and private sector health facilities in AEFI reporting for the first time in the country. Outcomes include an increased number of COVID-19 vaccine-related AEFIs reported and causality assessments completed, which means that potential safety issues were being analyzed more quickly, comprehensively, and accurately. The number of AEFI reports submitted to VigiBase by Pakistan's regulatory authority more than quintupled from approximately 5,000/quarter in 2021 to 28,555/quarter in 2022. In Ethiopia, by October 2022, 44,000 AEFI reports had been received, and 40 causality assessments completed. In both countries, timely AEFI data review and analysis led to prompt recommendations and regulatory actions, highlighting the far-reaching implications of strengthening the country-level pharmacovigilance systems. These strengthened systems are now in place for use with all vaccines.