UNASSIGNED: Background. Food allergy can range from mild to severe, life-threatening reactions with various symptoms and organ involvement. The impact of asthma on severe food-induced allergic reactions is not completely understood. In the hypothesis that asthma increases the risk of severe food-induced allergic reactions, the aim of this study is to compare the incidence of severe food-induced allergic reactions in patients with history of asthma compared with patients without history of asthma. Methods. We performed a systematic research on electronic databases, including PubMed, Scopus, and Web of Science. Observational studies, studies reporting medical characteristics of patients diagnosed with food allergy, and studies reporting medical history of patients with allergic reactions were included. The primary outcome was the incidence of severe food-induced allergic reactions in patients with history of asthma compared with patients without history of asthma. The protocol of this review was registered in PROSPERO (CRD42023448293). Results. Eight studies with a total of 90,367 patients met the inclusion criteria and were included, with a total population of 28,166 of patients with food allergy. The incidence of severe food-induced allergic reactions in patients with history of asthma compared with patients without history of asthma was increased (OR = 1.28; 95% CI 1.03-1.59; p = 0.03; I2 = 59%). Conclusions. Individuals with both food allergy and asthma are at high risk of severe, potentially fatal allergic reactions. Healthcare professionals should prioritize prevention and management strategies for these subjects.

CoronaVac (Sinovac) Covid-19 vaccine has recently been approved for emergency use by the World Health Organization. However, data on its reactogenicity in real-world settings is scant. This study aimed to compare self-reported post-vaccination adverse reactions between CoronaVac and Comirnaty (Pfizer-BioNTech).
We adopted a prospective cohort study design using online surveys from the day of first-dose vaccination with intensive follow-up through two weeks after the second dose (11 time points). The primary outcome was adverse reactions (any versus none) and secondary outcomes were the sub-categories of adverse reactions (local, systemic, and severe allergic reactions). Potential effect modification across multimorbidity status, older age, and sex was examined.
In total, 2,098 participants who were scheduled to complete the 14th-day survey were included, with 46.2% receiving Comirnaty. Retention rate two weeks after the second dose was 81.0% for the CoronaVac group and 83.6% for the Comirnaty group. Throughout the follow-up period, 801 (82.7%) of those receiving Comirnaty and 543 (48.1%) of those receiving CoronaVac reported adverse reactions. Adjusted analysis suggested that compared with Comirnaty, CoronaVac was associated with 83%-reduced odds of any adverse reactions [adjusted odds ratio (AOR) = 0.17, 95% confidence interval (CI) 0.15-0.20], 92%-reduced odds of local adverse reactions (AOR = 0.08, 95% CI 0.06-0.09), and 76%-reduced odds of systemic adverse reactions (AOR = 0.24, 95% CI 0.16-0.28). No significant effect modification was identified.
This post-marketing study comparing the reactogenicity of Covid-19 vaccines suggests a lower risk of self-reported adverse reactions following vaccination with CoronaVac compared with Comirnaty.

Two employees of the National Health Service (NHS) in England developed severe allergic reactions following administration of BNT162b2 vaccine against COVID-19 (coronavirus disease 2019). The British SmPC for the BNT162b2 vaccine already includes reference to a contraindication for use in individuals who have had an allergic reaction to the vaccine or any of its components. As a precautionary measure, the Medicines and Healthcare products Regulatory Agency (MHRA) has issued interim guidance to the NHS not to vaccinate in principle in \"patients with severe allergies\". Allergic reactions to vaccines are very rare, but vaccine components are known to cause allergic reactions. BNT162b2 is a vaccine based on an mRNA embedded in lipid nanoparticles and blended with other substances to enable its transport into the cells. In the pivotal phase III clinical trial, the BNT162b2 vaccine was generally well tolerated, but this large clinical trial, used to support vaccine approval by the MHRA and US Food and Drug Administration, excluded individuals with a \"history of a severe adverse reaction related to the vaccine and/or a severe allergic reaction (e.g., anaphylaxis) to a component of the study medication\". Vaccines are recognized as one of the most effective public health interventions. This repeated administration of a foreign protein (antigen) necessitates a careful allergological history before each application and diagnostic clarification and a risk-benefit assessment before each injection. Severe allergic reactions to vaccines are rare but can be life-threatening, and it is prudent to raise awareness of this hazard among vaccination teams and to take adequate precautions while more experience is gained with this new vaccine.

Further to the approval of the Coronavirus disease 2019 (COVID-19) vaccine BNT162b2, several severe anaphylaxis cases occured within the first few days of public vaccination. An investigation is taking place to understand the cases and their triggers. The vaccine will be administered to a large number of individuals worldwide and there are raising concerns that severe adverse events might occur. With the current information, the European Academy of Allergy and Clinical Immunology (EAACI) states its position for the following preliminary recommendations that are to be revised as soon as more data emerge. To minimize the risk of severe allergic reactions in vaccinated individuals, it is urgently required to understand the specific nature of the reported severe allergic reactions, including the background medical history of the individuals affected and the mechanisms involved. To achieve this goal, all clinical and laboratory information should be collected and reported. Mild and moderate allergic patients should not be excluded from the vaccine as this could have a significant impact on reaching the goal of population immunity. Healthcare practitioners vaccinating against COVID-19 are required to be sufficiently prepared to recognize and treat anaphylaxis properly with the ability to administer adrenaline. Further to vaccine administration, a mandatory observation period of at least 15 minutes should be followed for all individuals. The current data have not shown any higher risk for patients suffering from allergic rhinitis or asthma, and this message should be clearly stated by physicians to enable our patients to trust the vaccine. More than 30% of the population suffers from allergic diseases and the benefit of the vaccination clearly outweighs the risk of severe COVID-19 development.

Data from the anaphylaxis registry of German-speaking countries indicate that food is the most frequent elicitor of severe allergic reactions in children, insect venom is the most frequent elicitor in adults. The anaphylaxis registry considers data from patients of allergy centers. The aim of the present study was to collect data regarding elicitors, cofactors and the medical care of patients with severe allergic reactions seen by private practice allergists but also patients seen by emergency doctors. From June 2008 to December 2009 70 cases of severe allergic reactions from private practice allergists and 154 from emergency doctors in Berlin were registered. Our data show that the profile of elicitors differs among the reporting groups. The reported causes from allergists were severe reactions to food, insect venom and subcutaneous immunotherapy, the emergency doctors reported insect venom as the most frequent elicitor. Our data show that a systematic evaluation of severe allergic reactions can provide important data about elicitors and circumstances of anaphylaxis. Through a comparison with data from the anaphylaxis registry the analysis of the data from the emergency doctors will allow to determine how many patients with severe allergic reactions are seen by an allergist for further diagnostic work-up and subsequent therapy.