The risk of anaphylaxis behind authorized COVID-19 vaccines: a meta-analysis

Serious adverse drug reactions associated with anti-SARS-CoV-2 vaccines and their reporting trends in the EudraVigilance database

A serious adverse reaction (SADR) may follow a vaccination against SARS-CoV-2 infection. We aimed to explore symptoms and reporting trends of SADRs to anti-SARS-CoV-2 vaccines based on the EudraVigilance database. This retrospective observational study analysed 250,966 suspected SADRs (with 62.8% reported in females), following the administration of 733,837,251 vaccine doses against SARS-CoV-2. Pfizer BioNTech (Comirnaty-Tozinameran), Moderna (Spikevax-Elastomeran), Janssen (Jcovden) and AstraZeneca (Vaxzevria) vaccines were analysed. The assessment included 897 types of SADRs across 12 categories. The most common clinical manifestations of SADRs to anti-SARS-CoV-2 vaccines vaccines encompassed neuropsychiatric (n = 121,877), cardiovascular (n = 78,167), as well as musculoskeletal and connective tissue disorders (n = 63,994). After summarising all SADRs, vaccination with Comirnaty was associated with the lowest risk of experiencing SADRs (754/million administered doses), followed by Spikevax (785/million doses), Jcovden (1,248/million doses) and Vaxzevria (2,301/million doses; p < 0.001). Regarding the vaccine administration timelines, the reporting of SADRs tends to be delayed and occurs over a longer time (p < 0.001). SADRs associated with anti-SARS-CoV-2 vaccines seem to be relatively rare. Compared to adenovirus-based vector vaccines (Jcovden, Vaxzevria), mRNA vaccines appear to offer improved safety profiles (Comirnaty, Spikevax). The risk of SADR to any SARS-CoV-2 vaccine seems to be outweighed by the benefits of active immunization against the virus.

Post-Vaccination Anaphylaxis in Adults: A Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVES

Vaccines have been recognized as one of the most effective public health interventions. However, vaccine-associated anaphylaxis, although rare, is a serious adverse reaction. The incidence of anaphylaxis related to non-COVID-19 vaccines in adults remains underreported. This systematic review and meta-analysis aim to estimate the incidence of post-vaccination anaphylaxis across various vaccines in adults.

METHODS

A comprehensive literature search of PubMed, Embase, Scopus, and Web of Science identified studies on anaphylaxis following vaccination in adults (≥18 years), excluding COVID-19 vaccines. PRISMA 2020 guidelines were followed. The protocol was registered in PROSPERO in advance (ID CRD42024566928). Random-effects and fixed-effects models were used to pool data and estimate the logit proportion, with the logit-transformed proportion serving as the effect size, thereby allowing for the calculation of event rates.

RESULTS

A total of 37 studies were included in the systematic review, with 22 studies contributing to the meta-analysis, representing a combined population of 206,855,261 participants. Most studies focused on influenza vaccines (n = 15). Across all studies, 262 anaphylactic cases were reported, with 153 cases related to influenza vaccines, followed by herpes zoster virus vaccines (38 cases) and yellow fever vaccines (29 cases). Td/Tdap vaccine had the lowest rate (0.0001 per 100,000 participants). The overall random-effects model yielded a logit proportion of -10.45 (95% CI: -12.09 to -8.82, p < 0.001), corresponding to an event rate of 2.91 events per 100,000 subjects (95% CI: 0.56 to 14.73). Sensitivity analysis showed a higher incidence for influenza, hepatitis vaccines, and in vulnerable populations.

CONCLUSIONS

Anaphylaxis following vaccination in adults is rare but varies by vaccine type. Strengthened monitoring and preparedness are essential, especially in non-medical settings, to ensure a rapid response to anaphylaxis and maintain public confidence in vaccination programs.

Serious adverse events following immunization with COVID-19 vaccines in Lebanon: a retrospective analysis of the National Pharmacovigilance Database

Continuous surveillance and risk assessment of inactivated Coronavirus Disease 2019 (COVID-19)) vaccines provide an understanding of their safety profiles, guide vaccination strategy and public health policy. This study aims to analyze the characteristics and prevalence of officially reported serious adverse events following immunization (AEFIs) with inactivated COVID-19 vaccines by System Organ Class (SOC), age, and sex.To achieve this aim, a retrospective observational study was conducted between February 14th, 2021, and June 30th, 2022. Reported AEFIs were evaluated for data completeness. Causality assessment adhered to the World Health Organization guidelines.Findings revealed that the AEFIs occurrence did not significantly differ between vaccines used (ChAdOx1 vs. BNT162b2), sex, or SOC. The most prevalent AEFIs were vascular disorders (37%), followed by cardiac (25%) and nervous system disorders (14%). The adverse events were predominantly reported post-vaccination with the BNT162b2 vaccine, mainly after the first dose. The mean age was highest for miscellaneous disorders (70 ± 21.7 years) and the lowest for nervous system (46 ± 22 years) and immune system disorders (45 ± 19 years). Age differences were statistically different for vascular disorders (p = 0.003) and immune system disorders (p = 0.012).In conclusion, ongoing surveillance and risk assessment of the vaccine's safety profile is crucial for detecting potential safety signals. Active surveillance of the reported serious AEFIs is highly needed to support evidence-based vaccination strategies and maintain public confidence in immunization programs.

The Ambivalence of Post COVID-19 Vaccination Responses in Humans

The Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has prompted a massive global vaccination campaign, leading to the rapid development and deployment of several vaccines. Various COVID-19 vaccines are under different phases of clinical trials and include the whole virus or its parts like DNA, mRNA, or protein subunits administered directly or through vectors. Beginning in 2020, a few mRNA (Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273) and adenovirus-based (AstraZeneca ChAdOx1-S and the Janssen Ad26.COV2.S) vaccines were recommended by WHO for emergency use before the completion of the phase 3 and 4 trials. These vaccines were mostly administered in two or three doses at a defined frequency between the two doses. While these vaccines, mainly based on viral nucleic acids or protein conferred protection against the progression of SARS-CoV-2 infection into severe COVID-19, and prevented death due to the disease, their use has also been accompanied by a plethora of side effects. Common side effects include localized reactions such as pain at the injection site, as well as systemic reactions like fever, fatigue, and headache. These symptoms are generally mild to moderate and resolve within a few days. However, rare but more serious side effects have been reported, including allergic reactions such as anaphylaxis and, in some cases, myocarditis or pericarditis, particularly in younger males. Ongoing surveillance and research efforts continue to refine the understanding of these adverse effects, providing critical insights into the risk-benefit profile of COVID-19 vaccines. Nonetheless, the overall safety profile supports the continued use of these vaccines in combating the pandemic, with regulatory agencies and health organizations emphasizing the importance of vaccination in preventing COVID-19's severe outcomes. In this review, we describe different types of COVID-19 vaccines and summarize various adverse effects due to autoimmune and inflammatory response(s) manifesting predominantly as cardiac, hematological, neurological, and psychological dysfunctions. The incidence, clinical presentation, risk factors, diagnosis, and management of different adverse effects and possible mechanisms contributing to these effects are discussed. The review highlights the potential ambivalence of human response post-COVID-19 vaccination and necessitates the need to mitigate the adverse side effects.

Incidence and management of the main serious adverse events reported after COVID-19 vaccination

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2n first appeared in Wuhan, China in 2019. Soon after, it was declared a pandemic by the World Health Organization. The health crisis imposed by a new virus and its rapid spread worldwide prompted the fast development of vaccines. For the first time in human history, two vaccines based on recombinant genetic material technology were approved for human use. These mRNA vaccines were applied in massive immunization programs around the world, followed by other vaccines based on more traditional approaches. Even though all vaccines were tested in clinical trials prior to their general administration, serious adverse events, usually of very low incidence, were mostly identified after application of millions of doses. Establishing a direct correlation (the cause-effect paradigm) between vaccination and the appearance of adverse effects has proven challenging. This review focuses on the main adverse effects observed after vaccination, including anaphylaxis, myocarditis, vaccine-induced thrombotic thrombocytopenia, Guillain-Barré syndrome, and transverse myelitis reported in the context of COVID-19 vaccination. We highlight the symptoms, laboratory tests required for an adequate diagnosis, and briefly outline the recommended treatments for these adverse effects. The aim of this work is to increase awareness among healthcare personnel about the serious adverse events that may arise post-vaccination. Regardless of the ongoing discussion about the safety of COVID-19 vaccination, these adverse effects must be identified promptly and treated effectively to reduce the risk of complications.

Identifying patients at risk of anaphylaxis

Anaphylaxis is an acute, potentially fatal, systemic hypersensitivity reaction that warrants prompt diagnosis and management. It continues to be challenging to anticipate who may be at risk of a severe, life-threatening allergic reaction. Anaphylaxis can be caused by a range of allergens, such as certain foods, medications, latex, insect stings, etc. Cofactors that augment the severity of clinical symptoms and increase the risk of poor outcomes include exercise, stress, infectious diseases, underlying mast cell disease, active allergic disease such as asthma, advanced age, intake of certain medications, history of previous anaphylaxis, and delayed or missed administration of adrenaline. According to the European Anaphylaxis Registry, food is the major elicitor of anaphylaxis, especially eggs, cow milk, and nuts, in children and adolescents. Reaction to insect venom has also been noted in young adulthood. Early recognition of signs and symptoms and prompt treatment are crucial in anaphylaxis management to avoid serious and even fatal outcomes. It is crucial for both individuals and clinicians to identify the cause of anaphylaxis. Biomarkers of anaphylaxis, such as histamine, tryptase, platelet activation factor (PAF), chymase, carboxypeptidase A3, dipeptidyl peptidase I (DPPI), basogranulin, CCL-2, hsa-miR-451a, may be useful in diagnosis and management. The purpose of this review article is to present a comprehensive overview of current evidence and expert opinions regarding the risk factors that predispose individuals to anaphylaxis. Additionally, it provides insights into potential biomarkers and genetic markers for accurate diagnosis and management. This review underscores the significance of expert guidance in enhancing patient outcomes and enabling self-management of anaphylactic episodes.

Evaluation of short-term adverse events of COVID-19 vaccines: An observational study

Coronavirus disease 2019 (COVID-19) vaccines are the most effective tools in managing the pandemic. However, the concern about these vaccines is the occurrence of unwanted adverse events (AEs). This study aimed to evaluate the short-term AEs of COVID-19 vaccines (Sputnik V, Astrazenka, and Sinopharm). A cross-sectional study using an online questionnaire was conducted among 321 vaccinated individuals. Demographic information, history of drug use, prior infection with COVID-19, the type of vaccine, vaccination stage, local injection site complication, systemic complication, and allergic reactions were collected and evaluated. Local complications, including pain and swelling at the injection site, and systemic complications, including fever, fatigue, lethargy, lymphadenopathy, and diarrhea, were reported after the injection of the AstraZeneca vaccine was more than the other 2 vaccines; The prevalence of fatigue and lethargy was higher than other systemic complications. The least reported complication was due to lymphadenopathy. The Sinopharm vaccine showed a lower prevalence of AEs than the other 2. The rare AEs, such as facial paralysis, nasal bleeding, and urticarial, were further reported after injection of the AstraZeneca vaccine. In general, the severity of systemic complications after the second dose of the vaccine was also higher than the first dose. All 3 vaccines were safe and tolerable. The most commonly reported AEs were injection site pain (local) and fatigue and lethargy (systemic). These expected AEs occurred shortly after vaccination and indicated an early immune response after vaccination.

The role of vaccines in the COVID-19 pandemic: what have we learned?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged late in 2019 and caused the coronavirus disease 2019 (COVID-19) pandemic that has so far claimed approximately 20 million lives. Vaccines were developed quickly, became available in the end of 2020, and had a tremendous impact on protection from SARS-CoV-2 mortality but with emerging variants the impact on morbidity was diminished. Here I review what we learned from COVID-19 from a vaccinologist's perspective.

The usability of testing skin reaction applying skin prick tests with Comirnaty (Pfizer, USA) vaccine in detecting the risk of developing post-vaccination immediate hypersensitivity response (anaphylaxis) after administration of this vaccine

Introduction

COVID-19 vaccines became a relevant element of prevention during COVID-19 pandemic. It is worth highlighting the importance of severe allergic post-vaccination reactions.

Aim

To evaluate the usability of skin reaction tests using skin prick tests with Comirnaty (Pfizer, USA) vaccine in risk detection of the post-vaccine immediate hypersensitivity reaction (anaphylaxis) after administration of this vaccine [PvIHR(A)].

Material and methods

The analysis embraces 102 people, 85 women and 17 men with a history of immediate hypersensitivity (anaphylaxis) [IHR(A)]. Detailed medical history was collected and skin prick tests were made among participants. The positive and negative test results were illustrated in Figure 1.

Results

As it stands in Table 1, considering all participants of the study, a positive result of the skin prick tests was obtained only in 2 cases, a negative result in 99 and 1 result was questionable. The two positive results were found in participants from a group with a previous PvIHR(A) in their past medical history and they decided not to get vaccinated. The one questionable result was of a person that had PvIHR(A) after administration of the first dose of Comirnaty vaccine (Pfizer, USA). This person decided to get vaccinated again and there was no PvIHR(A) observed.

Conclusions

COVID-19 vaccination involves a low risk of anaphylaxis. Purposefulness of providing the skin prick tests using the mRNA vaccine is questionable, due to their low sensitivity and low specificity.

Use of adrenaline to manage suspected anaphylaxis following COVID-19 vaccination: An Australian retrospective cohort study

BACKGROUND

The rate of anaphylaxis following COVID-19 vaccinations is estimated to be 2-11 cases per million doses administered. However, adrenaline is occasionally used in individuals who are later diagnosed with immunisation stress-related responses, as their initial presenting signs and symptoms can appear similar to that of anaphylaxis. This study aims to describe the clinical profile of individuals who had received adrenaline following a COVID-19 vaccine and their subsequent revaccination outcomes.

METHODS

We examined notifications of cases who had received adrenaline following a COVID-19 vaccine in New South Wales, Australia. The cases were classified into Brighton Collaboration Case Definition (BCCD) for anaphylaxis, their clinical presentation, management and subsequent revaccination outcomes were compared.

RESULTS

From 22 February 2021 to 30 September 2021, there were 222 cases where adrenaline was administered. Of these, 32 (14 %) fulfilled Level 1 BCCD, 59 (27%) Level 2, 2 (1%) Level 3, 97 (44%) Level 4 and 32 (14 %) Level 5. The most commonly reported symptoms were sensation of throat closure (n = 116, 52%), difficulty breathing (n = 82, 37%) and nausea (n = 55, 25 %). Of the 176 (79%) individuals who proceeded to further vaccination, 89 (51%) received the same vaccine formulation and only 14 (8%) experienced another allergic adverse event with 9 (5%) receiving adrenaline.

CONCLUSION

Less than one in five individuals who received adrenaline met Level 1 BCCD criteria for anaphylaxis. Many reactions that were treated with adrenaline had little to no diagnostic certainty of anaphylaxis and in such cases repeat vaccination had a high likelihood of being tolerated. Increased awareness and education on objective signs and symptoms of anaphylaxis is required to ensure appropriate use of adrenaline.

COVID-19, post-acute COVID-19 syndrome (PACS, "long COVID") and post-COVID-19 vaccination syndrome (PCVS, "post-COVIDvac-syndrome"): Similarities and differences

Worldwide there have been over 760 million confirmed coronavirus disease 2019 (COVID-19) cases, and over 13 billion COVID-19 vaccine doses have been administered as of April 2023, according to the World Health Organization. An infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to an acute disease, i.e. COVID-19, but also to a post-acute COVID-19 syndrome (PACS, "long COVID"). Currently, the side effects of COVID-19 vaccines are increasingly being noted and studied. Here, we summarise the currently available indications and discuss our conclusions that (i) these side effects have specific similarities and differences to acute COVID-19 and PACS, that (ii) a new term should be used to refer to these side effects (post-COVID-19 vaccination syndrome, PCVS, colloquially "post-COVIDvac-syndrome"), and that (iii) there is a need to distinguish between acute COVID-19 vaccination syndrome (ACVS) and post-acute COVID-19 vaccination syndrome (PACVS) - in analogy to acute COVID-19 and PACS ("long COVID"). Moreover, we address mixed forms of disease caused by natural SARS-CoV-2 infection and COVID-19 vaccination. We explain why it is important for medical diagnosis, care and research to use the new terms (PCVS, ACVS and PACVS) in order to avoid confusion and misinterpretation of the underlying causes of disease and to enable optimal medical therapy. We do not recommend to use the term "Post-Vac-Syndrome" as it is imprecise. The article also serves to address the current problem of "medical gaslighting" in relation to PACS and PCVS by raising awareness among the medical professionals and supplying appropriate terminology for disease.

Real-life safety profile of mRNA vaccines for COVID-19: an analysis of VAERS database

Introduction

Since the first COVID-19 messenger RNA vaccines became available globally for emergency or conditional use, post-marketing surveillance activities have been implemented for the monitoring of any adverse events that might arise in daily clinical practice and were not detected earlier during clinical trials.

Methods

Safety data concerning the BNT162b2 and the mRNA-1273 COVID-19 vaccines were collected from the Vaccine Adverse Event Reporting System (VAERS) for the period from December 2020 to October 15, 2021. In addition to a descriptive analysis of individuals who experienced an adverse event after vaccination, a case-non-case analysis was performed by using the Reporting Odds Ratio with 95% confidence interval as statistical parameter for detecting differences in reporting rates between the two mRNA vaccines.

Results

At the cut-off date, a total of 758,040 reports were submitted to VAERS, of which 439,401 were related to the Pfizer-BioNTech (BNT162b2) vaccine and 318,639 to the Moderna vaccine (mRNA-1273). Most common adverse events following immunization for both mRNA vaccines were headache, fatigue, pyrexia, dizziness, nausea, pain, chills, and pain in extremity. A disproportionality was found for BNT162b2 as compared with mRNA-1273 for some events of special interest, such as myocarditis [ROR 2.00; 95% confidence interval (CI), 1.93 to 2.06], Bell’s palsy (1.34; 1.29 to 1.39), and anaphylactic shock (3.23; 2.96 to 3.53).

Conclusion

Even if some rare adverse events were identified, our survey of post-marketing surveillance has provided further evidence of the favourable safety profile of mRNA vaccines.

Monoclonal antibody infusion reaction with bamlanivimab and etesevimab in a 5-year-old male with coronavirus disease 2019: a case report

BACKGROUND

Bamlanivimab and etesevimab had been granted emergency use authorization in children under 12 years who are at risk of progression from mild/moderate coronavirus disease 2019 to severe disease and hospitalization.

CASE REPORT

We report on a 5-year-old white male with preexisting conditions, predisposing him to severe disease, who developed hypoxia and flushing 3 minutes into his infusion, thus meeting the criteria for anaphylaxis.

CONCLUSIONS

We believe this patient developed either an immunoglobulin E-mediated anaphylactic or a non-immunoglobulin E-mediated anaphylactoid reaction to bamlanivimab and etesevimab, which is an important possibility to consider on administration.

The conundrum of COVID-19 mRNA vaccine-induced anaphylaxis

Novel messenger RNA (mRNA) vaccines have proven to be effective tools against coronavirus disease 2019, and they have changed the course of the pandemic. However, early reports of mRNA vaccine-induced anaphylaxis resulted in public alarm, contributing toward vaccine hesitancy. Although initial reports were concerning for an unusually high rate of anaphylaxis to the mRNA vaccines, the true incidence is likely comparable with other vaccines. These reactions occurred predominantly in young to middle-aged females, and many had a history of allergies. Although initially thought to be triggered by polyethylene glycol (PEG), lack of reproducibility of these reactions with subsequent dosing and absent PEG sensitization point away from an IgE-mediated PEG allergy in most. PEG skin testing has poor posttest probability and should be reserved for evaluating non-vaccine-related PEG allergy without influencing decisions for subsequent mRNA vaccination. Immunization stress-related response can closely mimic vaccine-induced anaphylaxis and warrants consideration as a potential etiology. Current evidence suggests that many individuals who developed anaphylaxis to the first dose of an mRNA vaccine can likely receive a subsequent dose after careful evaluation. The need to understand these reactions mechanistically remains critical because the mRNA platform is rapidly finding its way into other vaccinations and therapeutics.

Safety of COVID-19 Pfizer-BioNtech (BNT162b2) mRNA vaccination in adolescents aged 12-17 years: A systematic review and meta-analysis

The COVID-19 pandemic has severely affected adolescents. Safe and effective vaccines are pivotal tools in controlling this pandemic. We reviewed the safety profile of the BNT162b2 COVID-19 vaccine in adolescents using mostly real-world data to assist decision-making. We used random-effects model meta-analysis to derive pooled rates of single or grouped adverse events following immunization (AEFI) after each primary and booster dose, as well as after combining all doses. Reporting on over one million participants with safety data were included. The most-reported local and systemic AEFIs were pain/swelling/erythema/redness and fatigue/headache/myalgia, respectively. AESIs were rarely reported but were more frequent after the second dose than they were after the first and the booster doses. Health impact was less common among adolescents after receiving BNT162b2 vaccine. Rare life-threatening AEFIs were reported across all doses in real-world studies. Our findings highlight the significance of enhancing national and regional vaccination programs to ensure public confidence.

vACcine COnfidence amongst those living with alleRgy during the COVID pandemic (ACCORD): a scoping review protocol

BACKGROUND

Reports of allergic reactions to the COVID-19 vaccines have been documented, which may also contribute to hesitancy. Despite the low likelihood that the COVID-19 vaccine will trigger an allergic reaction, we and others have reported that families with allergy remain vaccine hesitant due to concerns of COVID-19-vaccine-triggered anaphylaxis.

OBJECTIVE

To present our scoping review protocol, that will inform a forthcoming living scoping review in which we will investigate the peer-reviewed and grey literature on COVID-19 vaccine hesitancy and allergic disease and/or allergic reactions following a COVID-19 vaccine.

METHODS

Informed by Arksey and O'Malley framework for methodological review, we have developed a search strategy with content and methodological experts, and which has undergone Peer Review of Electronic Search Strategies review. A search of four scientific databases, as well as gray literature, will be performed without restriction to articles by type of COVID-19 vaccine, or country of study, and will include publications in the ten languages our team can handle. Bi-monthly search alerts based on the search strategy will be generated.

RESULTS

The first search will result in a stand alone peer reviewed scoping review. Bi-monthly updates will be posted on a pre-print server. Depending on the volume of literature, these updates will be synthesized and submitted for peer-review at 6 and/or 12 months.

CONCLUSION

COVID-19 vaccine hesitancy amongst individuals with allergy persists, despite very low risk of serious adverse reactions. Our living scoping review, which includes multiple forms of knowledge translation, will be a rigorous way to address hesitancy.

A Comparative Analysis of a Self-Reported Adverse Events Analysis after Receiving One of the Available SARS-CoV-2 Vaccine Schemes in Ecuador

The COVID-19 pandemic has put a lot of pressure on health systems worldwide. Mass vaccination against SARS-CoV-2 has reduced morbidity and mortality worldwide. Despite their safety profiles, vaccines, as with any other medical product, can cause adverse events. Yet, in countries with poor epidemiological surveillance and monitoring systems, reporting vaccine-related adverse events is a challenge. The objective of this study was to describe self-reported vaccine adverse events after receiving one of the available COVID-19 vaccine schemes in Ecuador. A cross-sectional analysis based on an online, self-reported, 32-item questionnaire was conducted in Ecuador from 1 April to 15 July 2021. Participants were invited by social media, radio, and TV to voluntarily participate in our study. A total of 6654 participants were included in this study. Furthermore, 38.2% of the participants reported having at least one comorbidity. Patients received AstraZeneca, Pfizer, and Sinovac vaccines, and these were distributed 38.4%, 31.1%, and 30.5%, respectively. Overall, pain or swelling at the injection site 17.2% (n = 4500) and headache 13.3% (n = 3502) were the most reported adverse events. Women addressed events supposedly attributable to vaccination or immunization [ESAVIs] (66.7%), more often than men (33.2%). After receiving the first dose of any available COVID-19 vaccine, a total of 19,501 self-reported ESAVIs were informed (87.0% were mild, 11.5% moderate, and 1.5% severe). In terms of the vaccine type and brand, the most reactogenic vaccine was AstraZeneca with 57.8%, followed by Pfizer (24.9%) and Sinovac (17.3%). After the second dose, 6776 self-reported ESAVIs were reported (87.1% mild, 10.9% moderate, and 2.1% severe). AstraZeneca vaccine users reported a higher proportion of ESAVIs (72.2%) in comparison to Pfizer/BioNTech (15.9%) and Sinovac Vaccine (11.9%). Swelling at the injection site, headache, muscle pain, and fatigue were the most common ESAVIs for the first as well as second doses. In conclusion, most ESAVIs were mild. AstraZeneca users were more likely to report adverse events. Participants without a history of COVID-19 infection, as well as those who received the first dose, were more prone to report ESAVIs.

The Impact of COVID-19 Pandemic on Dermatological Conditions: A Novel, Comprehensive Review

Background: The earliest cases of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2019. Since the declaration as a pandemic on 11 March 2020, further dermatological conditions continue to be documented. We herein present a novel literature review of dermatological manifestations associated with the Coronavirus Disease 2019 (COVID-19) pandemic. To date, this literature review is the first broad-spectrum examination that analyzes a range of dermatological manifestations related to the COVID-19 pandemic: infection, vaccinations, personal protective equipment (PPE), and psychosocial factors. Methods: A detailed literature search was conducted using key terms for cutaneous manifestations associated with the scope of this review. The search retrieved 2199 articles. Results: The COVID-19 pandemic has triggered a significant range of dermatologic sequela. Etiologies of lesions continue to be investigated. Proposed mechanisms include inflammatory response to spike protein, vitamin D deficiency, ACE2 receptor activation, androgen levels, and increased psychological stress. One prominent mechanism describes viral spike protein invasion into the dermis by binding to the angiotensin-converting enzyme 2 (ACE-2) receptors in keratinocytes, with a secondary immunological response. Conclusions: Dermatologists play an integral role in the proper diagnosis and treatment of COVID-related lesions. Early treatment regimens and timely prophylaxis have been shown to safely reduce infection-related dermatological sequelae. Additional investigations and data collection can reduce disease burden and improve overall prognosis.

Background incidence rates of adverse events of special interest related to COVID-19 vaccines in Ontario, Canada, 2015 to 2020, to inform COVID-19 vaccine safety surveillance

BACKGROUND

Background incidence rates are critical in pharmacovigilance to facilitate identification of vaccine safety signals. We estimated background incidence rates of 11 adverse events of special interest related to COVID-19 vaccines in Ontario, Canada.

METHODS

We conducted a population-based retrospective observational study using linked health administrative databases for hospitalizations and emergency department visits among Ontario residents. We estimated incidence rates of Bell's palsy, idiopathic thrombocytopenia, febrile convulsions, acute disseminated encephalomyelitis, myocarditis, pericarditis, Kawasaki disease, Guillain-Barré syndrome, transverse myelitis, acute myocardial infarction, and anaphylaxis during five pre-pandemic years (2015-2019) and 2020.

RESULTS

The average annual population was 14 million across all age groups with 51% female. The pre-pandemic mean annual rates per 100,000 population during 2015-2019 were 191 for acute myocardial infarction, 43.9 for idiopathic thrombocytopenia, 28.8 for anaphylaxis, 27.8 for Bell's palsy, 25.0 for febrile convulsions, 22.8 for acute disseminated encephalomyelitis, 11.3 for myocarditis/pericarditis, 8.7 for pericarditis, 2.9 for myocarditis, 2.0 for Kawasaki disease, 1.9 for Guillain-Barré syndrome, and 1.7 for transverse myelitis. Females had higher rates of acute disseminated encephalomyelitis, transverse myelitis and anaphylaxis while males had higher rates of myocarditis, pericarditis, and Guillain-Barré syndrome. Bell's palsy, acute disseminated encephalomyelitis, and Guillain-Barré syndrome increased with age. The mean rates of myocarditis and/or pericarditis increased with age up to 79 years; males had higher rates than females: from 12 to 59 years for myocarditis and ≥12 years for pericarditis. Febrile convulsions and Kawasaki disease were predominantly childhood diseases and generally decreased with age.

CONCLUSIONS

Our estimated background rates will permit estimating numbers of expected events for these conditions and facilitate detection of potential safety signals following COVID-19 vaccination.

COVID-19 Vaccination Is Safe among Mast Cell Disorder Patients, under Adequate Premedication

Reported cases of anaphylaxis following COVID-19 vaccination raised concerns about the safety of these vaccines, namely in patients suffering from clonal mast cell (MC) disorders-a heterogenous group of disorders in which patients may be prone to anaphylaxis caused by vaccination. This study aimed to assess the safety of COVID-19 vaccines in patients with clonal MC disorders. We performed an ambidirectional cohort study with 30 clonal MC disorder patients (n = 26 in the prospective arm and n = 4 in the retrospective arm), that were submitted to COVID-19 vaccination. Among these, 11 (37%) were males, and median age at vaccination date was 41 years (range: 5y to 76y). One patient had prior history of anaphylaxis following vaccination. Those in the prospective arm received a premedication protocol including H1- and H2-antihistamines and montelukast, while those in the retrospective arm did not premedicate. Overall, patients received a total of 81 doses, 73 under premedication and 8 without premedication. No MC activation symptoms were reported. COVID-19 vaccination seems to be safe in patients with clonal mast cell disorders, including those with prior anaphylaxis following vaccination. Robust premedication protocols may allow for vaccination in ambulatory settings.