Thrombosis With Thrombocytopenia and Post-COVID-Vaccination Syndrome With Anti-G-Protein-Coupled Receptor (GPCR) Antibodies Treated With Therapeutic Plasma Exchange

We present the case of a female who developed cerebral venous thrombosis with thrombocytopenia after inoculation with the anti-coronavirus disease 2019 (COVID-19) Vaxzevria vaccine, followed by splanchnic thrombosis and diffuse hemorrhages. Despite receiving treatment, the complications increased, and hence therapeutic plasma exchange (TPE) was attempted, leading to laboratory and clinical improvements and discharge after a period of intensive care. Almost two years after the first episode, in the interim of which the patient complained of only minor symptoms such as asthenia and difficulty concentrating, she developed an epileptic syndrome that required neurological treatment. In addition, her fatigue and difficulty concentrating worsened and other serious symptoms of dysautonomia appeared, such as trembling of her right arm, loss of stability, and postural orthostatic tachycardia. As serum analysis revealed a significant number of alterations in autoantibodies against various G-protein-coupled receptors (GPCRs) and RAS-related proteins, two further TPEs were performed, resulting in rapid and sustained clinical improvement. This report highlights the role of the different types of autoantibodies produced in response to anti-COVID-19 vaccination, which can have functional, regulatory, and possibly pathogenic effects on the vascular and nervous systems.

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

Background

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.

Methods

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.

Results

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.

Conclusion

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.

New-Onset Rheumatic Immune-Mediated Inflammatory Diseases Following SARS-CoV-2 Vaccinations until May 2023: A Systematic Review

A comprehensive, up-to-date systematic review (SR) of the new-onset rheumatic immune-mediated inflammatory diseases (R-IMIDs) following COVID-19 vaccinations is lacking. Therefore, we investigated the demographics, management, and prognosis of new R-IMIDs in adults following SARS-CoV-2 vaccinations. A systematic literature search of Medline, Embase, Google Scholar, LitCovid, and Cochrane was conducted. We included any English-language study that reported new-onset R-IMID in adults following the post-COVID-19 vaccination. A total of 271 cases were reported from 39 countries between January 2021 and May 2023. The mean age of patients was 56 (range 18-90), and most were females (170, 62.5%). Most (153, 56.5%) received the Pfizer BioNTech COVID-19 vaccine. Nearly 50% of patients developed R-IMID after the second dose of the vaccine. Vasculitis was the most prevalent clinical presentation (86, 31.7%), followed by connective tissue disease (66, 24.3%). The mean duration between the vaccine's 'trigger' dose and R-IMID was 11 days. Most (220, 81.2%) received corticosteroids; however, 42% (115) received DMARDs such as methotrexate, cyclophosphamide, tocilizumab, anakinra, IV immunoglobulins, plasma exchange, or rituximab. Complete remission was achieved in 75 patients (27.7%), and 137 (50.6%) improved following the treatment. Two patients died due to myositis. This SR highlights that SARS-CoV-2 vaccines may trigger R-IMID; however, further epidemiology studies are required.

Multivariate Analysis of Adverse Reactions and Recipient Profiles in COVID-19 Booster Vaccinations: A Prospective Cohort Study

BACKGROUND

This study investigated the impact of vaccinated population profiles, vaccine type/interval, and the number of vaccine doses on adverse reactions to receiving a coronavirus disease 2019 (COVID-19) booster vaccination.

METHODS

A survey of adverse reactions was conducted from January 2022 to December 2022 among Osaka University Dental Hospital employees who received their third or fourth doses. The study included 194 third-dose recipients and 131 fourth-dose recipients. Comparisons of the occurrence of adverse reactions between the third- and fourth-dose groups were analyzed via a chi-squared test. The relationships between each adverse reaction occurrence and recipient profiles, vaccine type/interval, and the number of vaccine doses were analyzed via a logistic regression analysis.

RESULTS

No significant differences were found in the occurrence of adverse reactions between the third and fourth doses. Younger recipients often developed injection site reaction, fatigue, chills, fever, arthralgia, headache, diarrhea, and any adverse reactions more often. Females had higher frequencies of fatigue, chills, headache, and nausea compared to males. Recipients without underlying diseases had higher frequencies of fever and nausea than those with underlying diseases.

CONCLUSIONS

Younger recipients and females were at higher risk for adverse reactions to a COVID-19 booster vaccination, while the number of vaccinations, vaccination interval, vaccine type, and cross-vaccination showed no significant associations.

Analysis of death cases in Shenyang City, China, for immunization adverse event surveillance, 2009-2021

Through the Chinese National Immunization Adverse Event Surveillance System (CNAEFIS), we collected reports of Adverse Event Following Immunization (AEFI) deaths in Shenyang from 2009 to 2021 with the aim of analyzing AEFI-related deaths and assessing the safety of vaccination. From 2009 to 2021, a total of 12 AEFI-related deaths were reported in Shenyang City, and autopsies were performed in 6 deaths. According to the assessment of the Expert Committee on Investigation and Diagnosis of AEFI 3 (25.0%) deaths were classified as severe vaccine reactions, 9 (75.0%) deaths were classified as coincidental events, and there were no immunization errors or psychological reactions. The overall estimated AEFI-related mortality rate was 0.12 per 100,000 vaccination doses. Spearman's rank correlation analysis showed no correlation between AEFI, severe vaccine reactions, and suspected vaccination-related deaths. Coincidental events are the most common type of death following vaccination, meaning that the risk of death following immunization is low, and ongoing AEFI surveillance and scientific causality assessment are essential to ensure the vaccine confidence. Detailed pre-vaccination health status questioning is also key to avoiding and reducing adverse events.

COVID-19 vaccination in the mass vaccination center: clinical practice and effectiveness analysis

Objectives

Mass vaccination campaigns can rapidly increase the vaccination rate for the COVID-19 vaccine, the establishment of mass vaccination centers is indispensable. At the beginning of March 2021, China began to carry out COVID-19 vaccination activities nationwide. Here, we aimed to evaluate the criteria established by mass vaccination centers, COVID-19 vaccination experience, the incidence of adverse events following immunization and opinions.

Methods

We describe the layout and functioning of Nan'an District mass vaccination center, the working mechanism, experience and effectiveness. Distribution of COVID-19 vaccine vaccination and adverse events following immunization reported in the mass vaccination center of Nan'an District were evaluated.

Results

From March 26, 2021 to April 28, 2022, the mass vaccination center has inoculated about 381,364 doses of COVID-19 vaccine to the population. The study found that the incidence of adverse events following immunization (AEFI) was very low (1.04/100000). The chances of having AEFI were significantly higher in COVID-19 vaccine (CHO cell) than COVID-19 vaccine (Vero cell).

Conclusion

The mass vaccination center was running successfully. It was effective and safe, providing vaccination services and increasing COVID-19 vaccination rates among the population. The experience of the mass vaccination center for COVID-19 in China can provide a reference for other countries and regions to carry out COVID-19 vaccination.

COVID-19 Vaccines and Atrial Fibrillation: Analysis of the Post-Marketing Pharmacovigilance European Database

Atrial fibrillation (AF) has been described in COVID-19 patients. Recently, some case reports and US pharmacovigilance analyses described AF onset as a rare adverse event following COVID-19 vaccination. The possible correlation is unclear. We systematically analyzed the reports of AF related to COVID-19 vaccines collected in the European pharmacovigilance database, EudraVigilance (EV), from 2020 to November 2022. We carried out descriptive and disproportionality analyses. Moreover, we performed a sensitivity analysis, excluding the reports describing other possible alternative AF causes (pericarditis, myocarditis, COVID-19, or other drugs that may cause/exacerbate AF). Overall, we retrieved 6226 reports, which represented only 0.3% of all those related to COVID-19 vaccines collected in EV during our study period. AF reports mainly referred to adults (in particular, >65 years old), with an equal distribution in sex. Reports were mainly related to tozinameran (54.04%), elasomeran (28.3%), and ChAdOx1-S (14.32%). The reported AF required patient hospitalization in 35% of cases and resulted in a life-threatening condition in 10% of cases. The AF duration (when reported) was highly variable, but the majority of the events had a short duration (moda = 24 h). Although an increased frequency of AF reporting with mRNA vaccines emerges from our study, other investigations are required to investigate the possible correlation between COVID-19 vaccination and the rare AF occurrence.

Adverse Events Following Immunization With mRNA and Viral Vector Vaccines in Individuals With Previous Severe Acute Respiratory Syndrome Coronavirus 2 Infection From the Canadian National Vaccine Safety Network

BACKGROUND

Adults previously infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develop short-term immunity and may have increased reactogenicity to coronavirus disease 2019 (COVID-19) vaccines. This prospective, multicenter, active-surveillance cohort study examined the short-term safety of COVID-19 vaccines in adults with a prior history of SARS-CoV-2.

METHODS

Canadian adults vaccinated between 22 December 2020 and 27 November 2021 were sent an electronic questionnaire 7 days post-dose 1, dose 2, and dose 3 vaccination. The main outcome was health events occurring in the first 7 days after each vaccination that prevented daily activities, resulted in work absenteeism, or required a medical consultation, including hospitalization.

RESULTS

Among 684 998 vaccinated individuals, 2.6% (18 127/684 998) reported a prior history of SARS-CoV-2 infection a median of 4 (interquartile range: 2-6) months previously. After dose 1, individuals with moderate (bedridden) to severe (hospitalized) COVID-19 who received BNT162b2, mRNA-1273, or ChAdox1-S vaccines had higher odds of a health event preventing daily activities, resulting in work absenteeism or requiring medical consultation (adjusted odds ratio [95% confidence interval]: 3.96 [3.67-4.28] for BNT162b2, 5.01 [4.57-5.50] for mRNA-1273, and 1.84 [1.54-2.20] for ChAdox1-S compared with no infection). Following dose 2 and 3, the greater risk associated with previous infection was also present but was attenuated compared with dose 1. For all doses, the association was lower or absent after mild or asymptomatic infection.

CONCLUSIONS

Adults with moderate or severe previous SARS-CoV-2 infection were more likely to have a health event sufficient to impact routine activities or require medical assessment in the week following each vaccine dose.

Concurrent hypereosinophilic syndrome and deep vein thrombosis after Pfizer-BioNTech COVID-19 vaccination: A case report

Herein, we report a case of eosinophilia syndrome and deep vein thrombosis presenting concurrently after the administration of the BNT162b2 mRNA-based coronavirus disease 2019 (COVID-19) vaccine. It is extremely rare to have both hypereosinophilic syndrome and deep vein thrombosis simultaneously. Both are serious diseases and should be treated with caution.

Safety and adverse events following COVID-19 vaccination among people with epilepsy: A cross-sectional study

OBJECTIVE

Epilepsy is a non-communicable disease costing a massive burden globally. It is known that there is increased prevalence of morbidity and mortality following COVID-19 infection among people with epilepsy (PWE). However, there is limited information about the adverse events following COVID-19 immunization among PWE. Hence, this study aimed to assess the safety and adverse events following immunization (AEFI) of various COVID-19 vaccines among PWE from our centre, focusing on neurological AEFI.

METHODS

This cross-sectional study recruited 120 adult PWE from the Neurology Clinic of the Universiti Kebangsaan Malaysia Medical Centre (UKMMC). Consent-taking was conducted via synchronous or asynchronous approaches, followed by a phone call interview session. The interview collected socio-demographic information, epilepsy-related variables, and vaccination-related variables. Univariate analysis and multiple logistic regression analysis were done to confirm factors associated with the AEFI of COVID-19 vaccination.

RESULTS

Among all types of COVID-19 vaccines, most of the PWE received the Cominarty® COVID-19 vaccination (52.5%). Overall, local AEFI was the quickest to develop, with an average onset within a day. PWE with normal body mass index (BMI) had a higher risk of developing both local and systemic AEFI compared to those underweight and obese PWE (OR: 15.09, 95% CI 1.70-134.28, P = 0.02).

SIGNIFICANCE

COVID-19 vaccines are safe for PWE. AEFI among PWE are similar to those of the general population following COVID-19 vaccination. Therefore, clinicians should encourage PWE to take COVID-19 vaccines.

A Retrospective Evaluation of Self-Reported Adverse Events Following Immunization with Different COVID-19 Vaccines in Türkiye

BACKGROUND

The Sinovac and BioNTech vaccines were the first to be introduced in Türkiye to fight the ongoing global COVID-19 pandemic. As these vaccines had shown some side-effects in its clinical trial, we aimed to conduct a survey study to assess the short-term adverse events following immunization (AEFIs) in Türkiye.

METHOD

A cross-sectional study was conducted using social and electronic media platforms by delivering a pre-formed and validated online questionnaire among people who had received at least one dose of the COVID-19 vaccine. This survey study focused on mass populations from different regions in Türkiye. A total of 603 responses were collected. Among these, 602 were selected based on complete answers and used for the assessment. The collected data were then analyzed to evaluate the various parameters related to the AEFIs of the respondents.

RESULTS

Among the total 602 participants, 20.8% were male, and 78.7% were female, actively answering all of the constructive questions. Most of the respondents were between 18-30 years of age. We found that a total of 23.3% of the total respondents had been infected with the SARS-CoV-2 virus. Our survey revealed that out of 602 volunteers, the rate of experiencing physical discomfort was higher in participants who had received the Pfizer-BioNTech vaccine at all three doses than in those who had received the Sinovac vaccine. When all vaccine types were examined, the most common side effect was pain at the injection site, reported by 75.19% participants. When the side effects were compared according to vaccine types, there was a significant difference only in terms of fever. Fever rates in those who had received the Pfizer-BioNTech vaccine (20.96%) were found to be significantly higher than those who had received the Sinovac vaccine (8%).

CONCLUSIONS

The studied vaccines showed minor side effects and there was no significant difference between the vaccines in terms of other side effects. Moreover, further research is needed to determine the efficacy of the existing vaccines in preventing SARS-CoV-2 infections or after-infection hospitalization.

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.

Safety evaluation on concomitant immunization with inactivated poliomyelitis vaccine produced from Sabin strains and other vaccines (from 2015 to 2020)

Objective

To evaluate the safety of concomitantly administering inactivated poliomyelitis vaccine produced from Sabin strains (sIPVs) with other vaccines.

Methods

A descriptive analysis was carried out on adverse events following immunization (AEFI) based on the administration of sIPV alone or concomitant with other vaccines (from 2015 to 2020) using data from the national AEFI surveillance system of China (CNAEFIS). All adverse reactions (ADRs) of the concomitant immunization were coded using a medical dictionary for regulatory activities (MedDRA) before comparison.

Results

The CNAEFIS reported a total of 9130 sIPV-related AEFI cases, including 6842 AEFI cases collected after immunization with sIPV alone and 2288 AEFI cases collected after immunization of sIPV concomitant with other vaccines. The combination of sIPV with diphtheria, tetanus and pertussis vaccine (DTaP) was correlated with the highest frequency of AEFI, which accounted for 53.50% of all 2288 AEFI cases. After MedDRA-based coding, the most frequent ADR was fever (70.18%), followed by erythema and swelling at the injection site (6.95%), induration at the injection site (3.85%), dermatitis allergy (3.56%) and urticaria (1.55%). A statistically significant difference (P < .001) was found between sIPV immunization and sIPV immunization concomitant with other vaccines for general reactions (95.36% and 93.22%, respectively) and abnormal reactions (4.64% and 6.78%, respectively).

Conclusion

No new safety signal is found for sIPV administered concomitantly, although its administration with other vaccines may increase the occurrence of abnormal reactions. Vaccine manufacturers should focus on the safety of administering sIPV with DTaP and carry out relevant clinical studies when necessary.

Serious adverse reaction associated with the COVID-19 vaccines of BNT162b2, Ad26.COV2.S, and mRNA-1273: Gaining insight through the VAERS

Background and purpose: Serious adverse events following immunization (AEFI) associated with the COVID-19 vaccines, including BNT162b2 (Pfizer-BioNTech), Ad26.COV2.S (Janssen), and mRNA-1273 (Moderna), have not yet been fully investigated. This study was designed to evaluate the serious AEFI associated with these three vaccines. Methods: A disproportionality study was performed to analyze data acquired from the Vaccine Adverse Event-Reporting System (VAERS) between 1 January 2010 and 30 April 2021. The reporting odds ratio (ROR) method was used to identify the association between the COVID-19 vaccines BNT162b2, Ad26.COV2.S, and mRNA-1273 and each adverse event reported. Moreover, the ratio of the ROR value to the 95% CI span was applied to improve the credibility of the ROR. The median values of time from vaccination to onset (TTO) for the three vaccines were analyzed. Results: Compared with BNT162b2 and mRNA-1273, Ad26.COV2.S vaccination was associated with a lower death frequency (p < 0.05). Ad26.COV2.S vaccination was associated with a lower birth defect and emergency room visit frequency than BNT162b2 (p < 0.05). There were 6,605, 830, and 2,292 vaccine recipients who suffered from COVID-19-related symptoms after vaccination with BNT162b2, Ad26.COV2.S, and mRNA-1273, respectively, including people who were infected by COVID-19, demonstrated a positive SARS-CoV-2 test, and were asymptomatic. Serious AEFI, including thromboembolism, hemorrhage, thrombocytopenia, cardiac arrhythmia, hypertension, and hepatotoxicity, were associated with all three vaccines. Cardiac failure and acute renal impairment events were associated with BNT162b2 and mRNA-1273, while seizure events were associated with BNT162b2 and Ad26.COV2.S. The median values of TTO associated with the three vaccinations were similar. Conclusion: These findings may be useful for health workers and the general public prior to inoculation, especially for patients with underlying diseases; however, the risk/benefit profile of these vaccines remains unchanged. The exact mechanism of SARS-CoV-2 vaccine-induced AEFI remains unknown, and further studies are required to explore these phenomena.

Analysis of Adverse Effects of COVID-19 Vaccines Experienced by Healthcare Workers at Guizhou Provincial Staff Hospital, China

Objective: A retrospective survey was conducted of adverse events following immunization (AEFI) experienced by health care workers (HCWs) in a relatively remote ethnic region in southwest China (Guizhou Province) who received COVID-19 vaccines. Methods: From 18 January 2021 to 21 January 2022, all HCWs of Guizhou Provincial Staff Hospital, China, who received at least one dose of inactivated COVID-19 vaccine (Vero cell), recombinant novel coronavirus vaccine (CHO cell), or one dose of adenovirus type-5 (Ad5) vectored COVID-19 vaccine were asked to complete a self-report questionnaire to provide information on any adverse events that may have occurred in the first 3 days after injection. The frequency of AEFI corresponding to the three types of vaccines were compared and the potential risks of AEFI due to the three different vaccines were predicted by multivariate logistic regression analysis. Results: Of the 904 HCWs who completed the survey, the rates of AEFI were 10.1% (80/794) due to Vero cell, 16.3% (13/80) due to CHO cell, and 46.67% (14/30) due to Ad5 vectored vaccines, and the rates were significantly different (χ2 = 38.7, p < 001) between the three vaccines. Multivariate logistic regression models predict that (1) compared to the Ad 5 vectored group, the risk of AEFI occurrence in the Vero cell group was reduced by about 85.9% (OR = 0.141, 95% CI: 0.065−0.306, p < 0.001) and in the CHO cell group by about 72.1% (OR = 0.279, 95% CI: 0.107−0.723, p = 0.009), (2) the odds for women experiencing AEFI were about 2.1 (OR = 2.093, 95% CI: 1.171−3.742, p = 0.013) times as high as those of men, and (3) the risk of AEFI for HCWs with a Bachelor’s degree or above was about 2.2 (OR = 2.237, 95% CI: 1.434−3.489, p = 0.001) times higher than in HCWs who do not have a Bachelor’s degree. Conclusions: 1. The inactivated COVID-19 vaccine (Vero cell), recombinant novel coronavirus vaccine (CHO cell), and adenovirus type-5 (Ad5) vectored COVID-19 vaccine made in China are safe and relatively broad-spectrum. 2. The prevalence of AEFI is more common in women healthcare workers. 3. The risk of AEFI was higher in those with a Bachelor’s degree or above and may be related to the psychological and social effects triggered by the global COVID-19 pandemic.

Advancing the Science of Vaccine Safety During the Coronavirus Disease 2019 (COVID-19) Pandemic and Beyond: Launching an International Network of Special Immunization Services

Within 2 years after the start of the coronavirus disease 2019 (COVID-19) pandemic, novel severe acute respiratory syndrome coronavirus 2 vaccines were developed, rigorously evaluated in large phase 3 trials, and administered to more than 5 billion individuals globally. However, adverse events of special interest (AESIs) have been described post-implementation, including myocarditis after receipt of messenger RNA (mRNA) vaccines and thrombosis with thrombocytopenia syndrome after receipt of adenoviral vector vaccines. AESIs are rare (<1 to 10/100 000 vaccinees) and less frequent than COVID-19 complications, though they have associated morbidity and mortality. The diversity of COVID-19 vaccine platforms (eg, mRNA, viral vector, protein) and rates of AESIs both between and within platforms (eg, higher rate of myocarditis after mRNA-1273 vs BNT162b2 vaccines) present an important opportunity to advance vaccine safety science. The International Network of Special Immunization Services has been formed with experts in vaccine safety, systems biology, and other relevant disciplines to study cases of AESIs and matched controls to uncover the pathogenesis of rare AESIs and inform vaccine development.

Using FHIR to Support COVID-19 Vaccine Safety Electronic Case Reports in America

During the COVID-19 pandemic, the Pan American Health Organization (PAHO) promoted several activities to strengthen the countries' emergency response. Vaccines represented a breakthrough in the pandemic evolution, even though they have not been equitably distributed. As most vaccines have received emergency authorizations for their timely delivery, vaccine safety surveillance has been highlighted for detecting early signals of potential adverse events following immunization (AEFI, also known as ESAVI). The objective of this article is to share the different steps, methodologies, and preliminary results of a regional policy to strengthen the ESAVI surveillance system in the Americas, including the adoption of HL7 FHIR for health information exchange between countries and PAHO.

Association of Current Active Illnesses and Severe Acute Kidney Injury after COVID-19 Vaccines: A Real-World Study

The administration of COVID-19 vaccines has become increasingly essential to curb the pandemic. However, adverse events of acute kidney injury (AKI) emerge rapidly as the COVID-19 vaccination promotes. To investigate the intervenable risk factors of AKI, we searched the Vaccine Adverse Event Reporting System database and recorded adverse effects after COVID-19 vaccines from Dec 2020 to Jun 2021. We included 1149 AKI cases, of which 627 (54.6%) cases were reported following the Pfizer-BNT COVID-19 vaccine, and 433 (37.7%) were reported after the Moderna vaccine. A univariate analysis revealed that coexisting active illnesses (infections, uncontrolled hypertension, heart failure, etc.) have an unfavorable prognosis, with an increased risk of death (OR 2.35, 95% CI 1.70−3.25, p < 0.001). The other risk factors included older age and past disease histories. An adjusted regression analysis proved that coexisting active illnesses worsen AKI prognosis after COVID-19 vaccination, with a higher mortality risk (OR 2.19, 95% CI 1.48−3.25, p < 0.001). In subgroup analysis, we stratified different variables, and none revealed a significant effect modification on the association between coexisting active illnesses and AKI-associated death after vaccination (p-interaction >0.05). We found that coexisting active illnesses could complicate AKI after vaccines, but the potential causal relationship needed further investigation.

Analysis of Neurological Adverse Events Reported in VigiBase From COVID-19 Vaccines

BACKGROUND

Fifteen COVID-19 vaccines have been granted emergency approval before the completion of conventional phases of clinical trials. The present study aimed to analyze the neurological adverse events (AEs) post-COVID-19 vaccination and focuses on determining the association of AEs with the vaccine.

METHODOLOGY

The neurological AEs reported for COVID-19 vaccines in the WHO pharmacovigilance database (VigiBase) were extracted from the System Organ Classes - neurological disorders and investigations. Descriptive statistics are reported as percentage and frequency and the disproportionality analysis was also conducted.

RESULTS

 For the neurological system, 19,529 AEs were reported. Of these, 15,638 events were reported from BNT162b2 vaccine, 2,751 from AZD1222 vaccine, 1,075 from mRNA-1273 vaccine, eight from Vero vaccine, two from Covaxin, and for 55 AEs, vaccine name was not mentioned. The reason for more AEs reported with BNT162b2 can be maximum vaccination with BNT162b2 vaccine in the study period. According to the disproportionality analysis based on IC₀₂₅ value, ageusia, anosmia, burning sensation, dizziness, facial paralysis, headache, hypoaesthesia, lethargy, migraine, neuralgia, paresis, parosmia, poor sleep quality, seizure, transient ischemic attack, and tremor are some of the AEs that can be associated with the administration of the vaccine.

CONCLUSION

The vaccines should be monitored for these AEs till the causality of these AEs with COVID-19 vaccines is established through further long-term follow-up studies. These neurological AEs reported in VigiBase should not be taken as conclusive and mass vaccination should be carried out to control the pandemic until a definite link of these adverse effects is established.

Hypotonic-hyporesponsive Episodes After Diphtheria, Tetanus and Acellular Pertussis Vaccination

BACKGROUND

Hypotonic-hyporesponsive episode (HHE) after whole cell pertussis vaccination is a known adverse event. Less is known about the risk of HHE after administration of acellular pertussis vaccines.

METHODS

Using parental interviews, this study actively surveyed for HHE among infants after doses 1 and 2 of acellular pertussis vaccine.

RESULTS

We interviewed the parents of 52,531 infants. HHE was reported at a rate of 22.8 per 100,000 doses (95% CI: 11.8-39.9) of acellular pertussis vaccine, approximately 45 episodes per 100,000 children.

CONCLUSIONS

These rates are lower than HHE rates reported after whole cell pertussis vaccines and within the range of HHE rates reported in other studies of acellular pertussis vaccines.

Adverse Events Following Immunization Associated with the First and Second Doses of the ChAdOx1 nCoV-19 Vaccine among Healthcare Workers in Korea

As worldwide large-scale inoculation of novel vaccines is on the way, the importance of real-world data on safety cannot be overemphasized. We aimed to investigate the adverse events following immunization (AEFIs) associated with the ChAdOx1 nCoV-19 vaccine among healthcare workers (HCWs). We investigated the systemic and local adverse events reported within seven days following the first and second doses of vaccination, using the mobile vaccine adverse events reporting system (MVAERS) developed by our hospital. The response rates were 71.8% (994/1384) and 52.9% (727/1375) after the first and second doses, respectively. The most commonly reported AEFIs were tenderness and pain at the injection site and fatigue after the first and second doses. In comparison to the first dose, the incidence and severity of AEFIs were lower following the second dose. Since the Korean government does not recommend the ChAdOx1 nCoV-19 vaccination for those under 30 years of age, with greater risk than benefit, we additionally compared the AEFIs of age groups under and above 30 years of age. The overall incidence of AEFIs was similar in both the under and over 30 age groups. In conclusion, AEFIs associated with the ChAdOx1 nCoV-19 vaccine were found to be tolerable, and AEFIs associated with the second dose were less common and severe compared to the first dose. Further safety surveillance studies on COVID-19 vaccines are required to validate our findings.

A Retrospective Cross-Sectional Study Assessing Self-Reported Adverse Events following Immunization (AEFI) of the COVID-19 Vaccine in Bangladesh

Background: The Oxford–AstraZeneca vaccine (Covishield) was the first to be introduced in Bangladesh to fight the ongoing global COVID-19 pandemic. As this vaccine had shown some side-effects in its clinical trial, we aimed to conduct a study assessing short-term adverse events following immunization (AEFIs) in Bangladesh. Method: A cross-sectional study was conducted on social and electronic media platforms by delivering an online questionnaire among people who had taken at least one dose of the COVID-19 vaccine. The collected data were then analysed to evaluate various parameters related to the AEFIs of the respondents. Results: A total of 626 responses were collected. Of these, 623 were selected based on complete answers and used for the analysis. Most of the respondents were between 30–60 years of age, and 40.4% were female. We found that a total of 8.5% of the total respondents had been infected with the SARS-CoV-2 virus. Our survey revealed that out of 623 volunteers, 317 reported various side-effects after taking the vaccine, which is about 50.88% of the total participants. The majority of participants (37.07%, 231/623) reported swelling and pain at the injection site and fever (25.84%, 162/623); these were some of the common localized and generalized symptoms after the COVID-19 vaccine administration. Conclusion: The side-effects reported after receiving the Oxford–AstraZeneca vaccine (Covishield) are similar to those reported in clinical trials, demonstrating that the vaccines have a safe therapeutic window. Moreover, further research is needed to determine the efficacy of existing vaccines in preventing SARS-CoV-2 infections or after-infection hospitalization.

Examining unsafe injection practices associated with auto-disable (AD) syringes: a systematic review

Auto-disable (AD) syringes are specifically designed to prevent syringe reuse. However, the notion that specific AD syringe designs may be unsafe due to reuse concerns related to the syringe's activation point has surfaced. We conducted a systematic review for evidence on the association between AD syringe design and syringe reuse, adverse events following immunization (AEFI), or blood borne virus (BBV) transmission. We found no evidence of an association between AD syringe design and unsafe injection practices including syringe reuse, AEFIs, or BBVs. Authors of three records speculated about the possibility of AD syringe reuse through intentionally defeating the disabling mechanism, and one hinted at the possibility of reuse of larger-than-required syringes, but none reported any actual reuse instance. In contrast to AD syringes, standard disposable syringes continue to be reused; therefore, the global health community should expand the use of AD syringes in both immunization and therapeutic context as an essential strategy for curbing BBV transmission.

Evaluation of Vaccine Safety After the First Public Sector Introduction of Typhoid Conjugate Vaccine-Navi Mumbai, India, 2018

BACKGROUND

In December 2017, the World Health Organization (WHO) prequalified the first typhoid conjugate vaccine (TCV; Typbar-TCV). While no safety concerns were identified in pre- and postlicensure studies, WHO's Global Advisory Committee on Vaccine Safety recommended robust safety evaluation with large-scale TCV introductions. During July-August 2018, the Navi Mumbai Municipal Corporation (NMMC) launched the world's first public sector TCV introduction. Per administrative reports, 113 420 children 9 months-14 years old received TCV.

METHODS

We evaluated adverse events following immunization (AEFIs) using passive and active surveillance via (1) reports from the passive NMMC AEFI surveillance system, (2) telephone interviews with 5% of caregivers of vaccine recipients 48 hours and 7 days postvaccination, and (3) chart abstraction for adverse events of special interest (AESIs) among patients admitted to 5 hospitals using the Brighton Collaboration criteria followed by ascertainment of vaccination status.

RESULTS

We identified 222/113 420 (0.2%) vaccine recipients with AEFIs through the NMMC AEFI surveillance system: 211 (0.19%) experienced minor AEFIs, 2 (0.002%) severe, and 9 serious (0.008%). At 48 hours postvaccination, 1852/5605 (33%) caregivers reported ≥1 AEFI, including injection site pain (n = 1452, 26%), swelling (n = 419, 7.5%), and fever (n = 416, 7.4%). Of the 4728 interviews completed at 7 days postvaccination, the most reported AEFIs included fever (n = 200, 4%), pain (n = 52, 1%), and headache (n = 42, 1%). Among 525 hospitalized children diagnosed with an AESI, 60 were vaccinated; no AESIs were causally associated with TCV.

CONCLUSIONS

No unexpected safety signals were identified with TCV introduction. This provides further reassurance for the large-scale use of Typbar-TCV among children 9 months-14 years old.

Surveillance of adverse events following the introduction of inactivated poliovirus vaccine made from Sabin strains (sIPV) to the Chinese EPI and a comparison with adverse events following inactivated poliovirus vaccine made from wild strains (wIPV) in Jiangsu, China

One dose of inactivated poliovirus vaccine (IPV) was introduced into the Chinese Expanded Program on Immunization (EPI) in 2016. IPV made from Sabin strains (sIPV) was newly licensed in China and its safety has been concerned. This study aimed to evaluate the safety of sIPV and provide a comparison with conventional IPV made from wild strains (wIPV). We collected all IPV-related AEFI reports in Jiangsu from the Chinese National Adverse Events Following Immunization Information System (CNAEFIS) for 2016-2019. We obtained the administered doses of IPV from the Jiangsu provincial Electronic Immunization Registries System (JSEIRS). The AEFI reporting rates per 100,000 doses of vaccine administered were compared for sIPV and wIPV. A total of 699 sIPV and 908 wIPV AEFI cases were collected by CNAEFIS in Jiangsu during 2016-2019. The overall AEFI reporting rates were 53.02 per 100,000 doses and 41.25 per 100,000 doses for sIPV and wIPV, respectively (P < .001). For both sIPV and wIPV, the AEFIs were mainly classified as common adverse reactions. The reporting rate of common adverse reactions was higher for sIPV than for wIPV (P < .001). The most frequently reported symptoms/signs were fever, persistent crying, injection site erythema/swelling, rash, and injection site induration. Only 1.14% of sIPV-associated and 2.31% of wIPV-associated AEFI cases were diagnosed as serious. No difference in reporting rate was observed for serious AEFIs (P = .272). sIPV has a favorable safety profile, although it exhibits a slightly higher reporting rate of common adverse reactions than wIPV.

Adverse events following immunization with bivalent oral poliovirus vaccine in Jiangsu, China

AIMS

The bivalent oral poliovirus vaccine (bOPV; Sabin types 1 and 3) replaced the trivalent OPV (Sabin types 1, 2 and 3) globally in April 2016. A routine schedule of 1 dose of inactivated poliovirus vaccine and 3 subsequent doses of bOPV was implemented in Jiangsu simultaneously. The schedule was changed to 2 inactivated poliovirus vaccines + 2 bOPV on 1 September 2019. Although OPV type 2 has been removed, challenges persist because of adverse events following immunization (AEFIs) with bOPV. Therefore, we analysed and evaluated the safety profile of bOPV administered in children based on passive postmarketing AEFI surveillance.

METHODS

We collected all bOPV-related AEFI reports in Jiangsu from the Chinese National AEFI Information System (CNAEFIS) between May 2016 and April 2020. We obtained the administered doses of bOPV from the Jiangsu Provincial Electronic Immunization Registries System. A descriptive analysis was performed.

RESULTS

In total, 2084 bOPV-related AEFIs were retrieved from the CNAEFIS. The overall reporting rate was 24.16 per 100 000 doses. Most AEFIs were nonserious. The most frequently reported symptoms were fever, rash and gastrointestinal disorders. Only 1.34% of AEFIs were serious, which thrombocytopenic purpura accounted for the largest category. Seventeen serious adverse events, including 2 vaccine-associated paralytic poliomyelitis (VAPP) cases, were considered to be related to bOPV vaccination. The rate of VAPP was 0.2 per million doses.

CONCLUSION

AEFI analysis showed that bOPV was well tolerated. The events most frequently reported were nonserious. However, bOPV can still cause VAPP. Attention should be given to risks related to bOPV.

Inclusion of Safety-Related Issues in Economic Evaluations for Seasonal Influenza Vaccines: A Systematic Review

(1) Background: Vaccines for seasonal influenza are a good preventive and cost-effective strategy. However, it is unknown if and how these economic evaluations include the adverse events following immunization (AEFI), and what the impact of such inclusion is on the health economic outcomes. (2) Methods: We searched the literature, up to January 2020, to identify economic evaluations of seasonal influenza vaccines that considered AEFIs. The review protocol was published in PROSPERO (CDR42017058523). (3) Results: A total of 52 economic evaluations considered AEFI-related parameters in their analyses, reflecting 16% of the economic evaluations on seasonal influenza vaccines in the initial study selection. Most studies used the societal perspective (64%) and evaluated vaccination of children (37%). Where considered, studies included direct medical costs of AEFIs (90%), indirect costs (27%), and disutilities/quality-adjusted life years loss due to AEFIs (37%). The majority of these studies accounted for the effects of the costs of AEFI on cost-effectiveness for Guillain–Barré syndrome. In those papers allowing cost share estimation, direct medical cost of AFEIs was less than 2% of total direct costs. (4) Conclusions: Although the overall impact of AEFIs on the cost-effectiveness outcomes was found to be low, we urge their inclusion in economic evaluations of seasonal influenza vaccines to reflect comprehensive reports for the decision makers and end-users of the vaccination strategies.

Post-marketing surveillance of adverse events following measles, mumps, rubella and varicella (MMRV) vaccine: retrospecive study in apulia region (ITALY), 2009-2017

Since 2006, some Italian Regions introduced the active offer of measles, mumps, rubella, and varicella (MMRV) vaccine for all newborns during the second years of life. In 2011, Italian Drug Authority (AIFA) recommended the discontinuation of the MMRV use for an increased risk of febrile seizures following vaccination; furthermore, some Regions (such as Apulia, that introduced MMRV offer in 2009) chose to continue the use of MMRV and Ministry of Health recommended to guarantee supplemental monitoring of safety of the vaccine. In Italy, the surveillance of Adverse Events following immunization (AEFIs) is currently carried out by AIFA and Regional Health Authorities; this paper aims to summarize the results of MMRV-vaccine surveillance of AEFIs program carried out in Apulia. From the AIFA database, we selected MMRV AEFIs that occurred in Apulia (about 4,000,000 inhabitants) from 2009 to 2017. For serious AEFIs, we applied the WHO causality assessment algorithm, using for cases hospitalized information from individual medical records. In the 8 years of observation, 155 MMRV-AEFIs (reporting rate: 37.9×100,000 doses) occurred of which 26 were classified as serious (6.3×100,000 doses) and 22 led to hospitalization. Performing causality assessment, for 10 the classification was "consistent causal association to immunization" (reporting rate: 2.4×100000 doses), for 2 indeterminate, for 13 "inconsistent causal association to immunization" and for 1 not-classifiable. No case of febrile seizure resulted consistent to vaccination. All consistent serious AEFIs were completely resolved at subsequent follow-up.

Characteristics of Adverse Events Following Immunization Reporting in Children: The Japanese Adverse Drug Event Report Database

The present study aimed to describe the trends and characteristics of adverse events following immunization (AEFI) reporting for children in the Japanese Adverse Drug Event Report database (JADER). We used 6280 AEFI reports for children aged <19 years among 504,407 ADR reports included in the JADER from 2004 to 2017. The number of AEFI reports gradually increased among children aged <10 years and was the highest in 2011 among children aged 10–19 years. The number of suspected vaccines per AEFI report increased after 2011 among children aged <10 years. The percentage of “death” and “did not recover” as AEFI outcomes reported were 4.3% and 3.7% among children aged <10 years and 0.2% and 21.1% among children aged 10–19 years, respectively. The most frequently reported vaccine–reaction pair was Haemophilus influenzae type b conjugate vaccine and pyrexia among children aged <10 years and recombinant adsorbed bivalent human papillomavirus-like particle vaccine and a loss of consciousness among children aged 10–19 years. It is necessary to consider the Weber effects to understand the trend and characteristics of AEFI reporting because pharmacovigilance activity regarding vaccination is not sufficient in Japan.

Participant-Centered Online Active Surveillance for Adverse Events Following Vaccination in a Large Clinical Trial: Feasibility and Usability Study

Background

Active participant monitoring of adverse events following immunization (AEFI) is a recent development to improve the speed and transparency of vaccine safety postmarketing. Vaxtracker, an online tool used to monitor vaccine safety, has successfully demonstrated its usefulness in postmarketing surveillance of newly introduced childhood vaccines. However, its use in older participants, or for monitoring patients participating in large clinical trials, has not been evaluated.

Objective

The objective of this study was to monitor AEFIs in older participants enrolled in the Australian Study for the Prevention through the Immunisation of Cardiovascular Events (AUSPICE) trial, and to evaluate the usefulness and effectiveness of Vaxtracker in this research setting.

Methods

AUSPICE is a multicenter, randomized, placebo-controlled, double-blinded trial in which participants aged 55 to 61 years were given either the pneumococcal polysaccharide vaccine (23vPPV) or 0.9% saline placebo. Vaxtracker was used to monitor AEFIs in participants in either treatment arm through the administration of two online questionnaires. A link to each questionnaire was sent to participants via email or short message service (SMS) text message 7 and 28 days following vaccination. Data were collated and analyzed in near-real time to identify any possible safety signals indicating problems with the vaccine or placebo.

Results

All 4725 AUSPICE participants were enrolled in Vaxtracker. Participant response rates for the first and final survey were 96.47% (n=4558) and 96.65% (n=4525), respectively. The online survey was completed by 90.23% (4083/4525) of Vaxtracker participants within 3 days of receiving the link. AEFIs were reported by 34.40% (805/2340) of 23vPPV recipients and 10.29% (240/2332) of placebo recipients in the 7 days following vaccination. Dominant symptoms for vaccine and placebo recipients were pain at the injection site (587/2340, 25.09%) and fatigue (103/2332, 4.42%), respectively. Females were more likely to report symptoms following vaccination with 23vPPV compared with males (433/1138, 38.05% versus 372/1202, 30.95%; P<.001).

Conclusions

Vaxtracker is an effective tool for monitoring AEFIs in the 55 to 61 years age group. Participant response rates were high for both surveys, in both treatment arms and for each method of sending the survey. This study indicates that administration of 23vPPV was well-tolerated in this cohort. Vaxtracker has successfully demonstrated its application in the monitoring of adverse events in near-real time following vaccination in people participating in a national clinical trial.

Trial Registration

Australian New Zealand Trial Registry Number (ACTRN) 12615000536561; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368506

Vaccines Safety in Children and in General Population: A Pharmacovigilance Study on Adverse Events Following Anti-Infective Vaccination in Italy

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.

Challenges in implementing yearly enhanced safety surveillance of influenza vaccination in Europe: lessons learned and future perspectives

Seasonal influenza vaccines are frequently reformulated, leading to specific challenges for continuous benefit/risk monitoring. In 2014, the European Medicines Agency started requiring annual enhanced safety surveillance (ESS). This article provides a perspective on ESS studies conducted ever since and aims to map existing initiatives used to monitor adverse events following influenza immunization. Of 11 ESS studies, reporting surveillance data of at least five different vaccine brands during four seasons, all were able to rapidly capture vaccine-specific adverse events of interest reports. However, challenges have been identified during study implementation, including recruitment of sufficient participants, enrolling younger age groups, collecting data of vaccine batch numbers, comparing observed with expected rates and achieving adequate return of reported events. Harmonizing safety monitoring standards across countries, and bridging between routine pharmacovigilance and ESS, is likely to allow more comprehensive assessments of influenza vaccine safety, requiring close collaboration between regulators, public health, and manufacturers.

Safety profile of human papilloma virus vaccines: an analysis of the US Vaccine Adverse Event Reporting System from 2007 to 2017

AIMS

Human papilloma virus (HPV) is the cause of different types of carcinoma. Despite the remarkable effectiveness of the HPV vaccines, there have been many complaints about their risk-benefit profile due to adverse events following immunization (AEFI). The purpose of this study is to analyse the safety profile of the HPV vaccine basing on real-life data derived from reports of suspected AEFIs collected in the US Vaccine Adverse Events Reporting System (VAERS) and assess if the searches on Google overlap with spontaneous reporting.

METHODS

We collected all the reports in VAERS between January 2007 to December 2017 related to the HPV vaccines. A disproportionality analysis using reporting odds ratio (ROR) with 95% confidence interval was performed.

RESULTS

Over the 10-year period, 55 356 reports of AEFI related to HPV vaccines were retrieved in VAERS, corresponding to 224 863 vaccine-event pairs. The highest number of reports was related to Gardasil (n = 42 244). The two events more frequently reported and statistically significant for HPV vaccines were dizziness (n = 6259; ROR = 2.60; 95% confidence interval 2.53-2.66) and syncope (n = 6004; ROR = 6.28; 95% confidence interval 6.12-6.44). The trends of spontaneous reporting and Google searches overlap.

CONCLUSION

The AEFI analysis showed that the events most frequently reported were non-serious and listed in the corresponding summary of product characteristics. Potential safety signals arose regarding less frequent AEFIs that would deserve further investigation. It is extremely important to disseminate correct and evidence-based scientific information.

Incomplete Vaccination Among Children With Special Health Care Needs in Zhejiang, China: Analysis of Retrospective Data

Objective: There is a lack of data relating to vaccination of children with special health care needs (CSHCN) and its influencing factors in China. We investigated the disease spectrum of CSHCN at the Vaccination Consultation Clinic in Zhejiang province as well as the underlying factors of vaccination recommendations of these children. Methods: In this study, we retrospectively analyzed the data of 4,525 CSHCN, who visited to our clinic for a vaccination consultation from January 1, 2016 to May 30, 2018. Descriptive data were presented as mean ± standard deviation (SD) and percentages. Multivariate analysis was performed with non-conditional bivariate logistic regression to identify the underlying factors of vaccination recommendations. Subsequent information regarding the following vaccination and the occurrence of AEFI were also collected and analyzed. Results: The main diseases consulted were those relating to the circulatory and nervous systems as well as neonatal diseases. The distribution of diseases varied by age: 53.6% infants under 12 months were counseled for circulatory system diseases, while 44.6% children aged 12~24 months and 54.7% children over 25 months were counseled for nervous system diseases. According to the evaluation reports issued by the consultation clinic, 75.0% of CSHCN were recommended to be vaccinated normally, 21.2% were recommended to defer specific vaccination, while only 3.8% were recommended to defer all vaccinations. In logistic regression analysis, age, history of adverse events following immunization (AEFI) and the number of diseases combined were all strong correlative factors for vaccination recommendations. Children who were aged over 25-month-old (OR = 1.34, 95%CI: 1.11-1.61) or had a history of AEFI (OR = 3.77, 95%CI: 2.83~5.01) or those who had numerous diseases combined (OR = 2.00, 95%CI: 1.46~2.75) tended to have a higher rate of deferred vaccination recommendation. Among those CSHCN who received nationally-recommended vaccines, the estimated AEFI rate was 24.29/100 000. No uncommon or rare serious adverse reactions were detected. Conclusion: Age, history of AEFI, and the number of diseases combined were important factors that affected the vaccination recommendations of CSHCN. Most CSHCN can be safely vaccinated according to the nationally-recommended schedule.

Parental Approach to the Prevention and Management of Fever and Pain Following Childhood Immunizations: A Survey Study

Antipyretic analgesics are commonly used to prevent and treat adverse events following immunizations. Current practice discourages routine use due to possible blunting of vaccine immune responses. We surveyed 150 parents/caregivers of recently vaccinated 6- and 15-month-old children to determine the prevalence of and beliefs regarding antipyretic analgesics use around vaccinations. 11% used them prophylactically, before vaccination. Use in the first 48 hours after vaccination was 64%, primarily to prevent and/or treat fever and pain. Acetaminophen was administered 2.6 times more frequently than ibuprofen. Ibuprofen was used more in the 15-month compared with the 6-month-old children (28% vs 7.4%, respectively, P = .001). The majority of caregivers disagreed with their use for fever (53%) or pain (59%). Antipyretic analgesic use, including prophylaxis, around vaccinations was common in our study population. Effective interventions are needed to target parents/caregivers to eliminate unnecessary antipyretic analgesic use around vaccination time and foster nonmedication alternatives.

Assessing the risk of intussusception and rotavirus vaccine safety in Canada

BACKGROUND

Intussusception has been identified as a rare adverse event following rotavirus immunization. We sought to determine the incidence of intussusception among infants in Canada both before and after introduction of rotavirus immunization programs.

METHODS

We used Canadian Institute for Health Information (CIHI) Discharge Abstract Database (DAD) to identify infants under 1 y of age who were admitted to a Canadian hospital, which the exception of Quebec, which does not submit data to CIHI, with a diagnosis of intussusception (ICD-10 code K56.1, and ICD-9 code 560) between January 1st, 2003 and December 31, 2013. We compared rates of intussusception hospitalization before and after rotavirus vaccine program introduction. Rates were adjusted for calendar year, age (in months), sex and region using Poisson regression models. Denominator data for infants under 1 year, stratified by age in months, were obtained from Statistics Canada.

RESULTS

Annual intussusception hospitalization rates ranged from 20-30 per 100,000 infants over the study period, with no evidence of a trend over time. Intussusception hospitalization rates were highest in infants 4 to <8 months and lowest in those under 2 months or between 10 and <12 months. Males had higher rates than females both overall and within each age group. The rate of intussusception hospitalization after rotavirus vaccine program introduction was 22.4 (95% CI: 18.3, 27.4) compared to 23.4 (95% CI: 21.5, 25.4) per 100,000 before program introduction.

CONCLUSIONS

We have described baseline intussusception hospitalization rates for infants in Canada and have found no evidence of a change in rate after implementation of routine rotavirus immunization programs.

The safety of maternal immunization

Maternal vaccination offers the opportunity to protect pregnant women and their infants against potentially serious disease. As both pregnant women and their newborns are vulnerable to severe illness, the potential public health impact of mass maternal vaccination programs is remarkable. Several high-income countries recommend seasonal influenza and acellular pertussis vaccines, and many developing countries recommend immunization against tetanus during pregnancy. There is a significant amount of literature supporting the safety of vaccination during pregnancy. As other vaccines are newly introduced for pregnant women, routine systems for monitoring vaccine safety in pregnant women are needed. To facilitate meta-analyses and comparison across systems and studies, future research and surveillance initiatives should utilize the same criteria for defining adverse events following immunization among pregnant women. At least 2 areas require further exploration: 1) identification of pregnancy outcomes associated with concomitant and closely spaced vaccines; 2) evaluation of possible improvement in birth outcomes associated with maternal vaccination. Given the public health impact of maternal vaccination, the existing evidence supporting the safety of vaccination during pregnancy should be used to reassure pregnant women and their providers and improve vaccine uptake in pregnancy.

Hepatitis B vaccine adverse events in China: risk control and regulation

The death of 17 children raised public fears over infant hepatitis B vaccination in China. Though the relation between hepatitis B and children's death was denied after prudent investigation, the negative impact remained. In order to prevent or minimize adverse events after vaccination, special strategy including regulation and reimbursement should be developed.

Routine surveillance of adverse events following immunization as an important tool to monitor vaccine safety

Post licensure surveillance of adverse events following immunization (AEFI) is a fundamental activity to improve safety and maintain public confidence in vaccines.   Since 2011, the Liguria Region has been involved in the inter-regional project of post-marketing surveillance of AEFI, coordinated by the Italian Medicine Agency and the Veneto region. The main objectives of the project are: (1) to coordinate the surveillance activities in the 8 Italian Regions included in the project; (2) to encourage the signal of AEFI by healthcare workers and patients; (3) to organize education activities addressed to health care workers, and, finally; (4) to establish vaccination counseling services in each Region. In particular, the Ligurian multidisciplinary team, composed by physicians expert in the field of vaccination and pharmacists, is involved in the causality assessment between vaccines and all adverse events signaled within the Liguria Region and in the analysis of all adverse events signaled in Italy as possibly related to influenza vaccines. During 2013, the team has organized 4 courses, addressed to healthcare personnel of vaccination outpatient clinics, focused on European and Italian legislation on pharmaco-vigilance and vaccine-vigilance and aimed at promoting signal of AEFI. Since October 2013, the Liguria Region has been participating to the inter-regional project of active surveillance of adverse events aimed at promoting the signal of AEFI by parents of vaccinated infants. After two years of implementation of the project both the number of reported AEFI and the reporting rate per 100 000 administered doses of vaccine increased. The activities need to be consolidated in the next years in order to guarantee high standard of vaccine safety, maintain the confidence in current immunization programs and reach optimal vaccination coverage rate.

Active assessment of adverse events following yellow fever vaccination of persons aged 60 years and more

INTRODUCTION

Older age has been associated to serious adverse events (AE) following yellow fever (YF) vaccination in passive surveillance studies, but few prospective studies involving seniors have been published.

RESULTS

A total of 906 persons were evaluated; 78 were not vaccinated and 828 received the vaccine; 700 (84.7%) were interviewed after vaccination: 593 (84.7%) did not report any symptoms or signs following YF vaccine; 107 (15.3%) reported at least one AE temporally associated to YF vaccination: 97 (13.9%) had systemic AE and 17 (2.4%) reported AE at the injection site (7 had both systemic and local AE). Data regarding previous vaccination was available for 655 subjects. Statistically significant higher rates of systemic AE were observed among subjects who received the first YF vaccination (17.5%) in comparison to persons who had been previously vaccinated (9.5%).

METHODS

This observational prospective study aimed to describe AE following YF vaccination in persons aged ≥ 60 y. From March 2009 to April 2010, seniors who sought YF vaccination at a reference Immunization Center in São Paulo city, Brazil, were included. Demographic and clinical data, previous YF vaccination, travel destination and the final decision regarding YF vaccination or not were collected from standardized medical records. Active AE assessment was done through telephone or electronic mail interview performed approximately 14 d after immunization.

CONCLUSION

Most persons aged ≥ 60 y may be safely vaccinated against YF. Before vaccination, they must be carefully screened for conditions associated to altered immunocompetence and for risk of exposure to YF.