Contributor:  Peter Bakes, MD Educational Pearls: Incidence 2.5-10 per million people occurring primarily in those with environmental allergens Typically occurs with mRNA vaccines in lipid nanoparticles (Moderna/Pfizer) rather than the adenovirus vaccine (J&J) Recommendation is to forego 2nd dose of the mRNA vaccine and instead get the adenovirus vaccine after weighing the risks and benefits References Kounis NG, Koniari I, de Gregorio C, Velissaris D, Petalas K, Brinia A, Assimakopoulos SF, Gogos C, Kouni SN, Kounis GN, Calogiuri G, Hung MY. Allergic Reactions to Current Available COVID-19 Vaccinations: Pathophysiology, Causality, and Therapeutic Considerations. Vaccines (Basel). 2021 Mar 5;9(3):221. doi: 10.3390/vaccines9030221. PMID: 33807579; PMCID: PMC7999280. Blumenthal KG, Robinson LB, Camargo CA, et al. Acute Allergic Reactions to mRNA COVID-19 Vaccines. JAMA. Published online March 08, 2021. doi:10.1001/jama.2021.3976 Summarized by John Spartz, MS3 | Edited by Erik Verzemnieks, MD   The Emergency Medical Minute is excited to announce that we are now offering AMA PRA Category 1 credits™ via online course modules. To access these and for more information, visit our website at www.emergencymedicalminute.com/cme-courses/ and create an account.  Donate to EMM today!