COVID-19 VACCINE ADMINISTRATION IN PATIENTS WITH FIRST-DOSE ADVERSE REACTIONS OR HISTORY OF SEVERE ALLERGIC REACTION

INTRODUCTION: The COVID-19 pandemic has claimed over 6 million lives from 2020 onward. Vaccines against SARS-CoV-2 are one of our best tools in preventing severe illness and mortality. There have been multiple reactions reported to the SARS-CoV-2 vaccine that initially precluded further revaccinations, making protection against the virus incomplete. Our study aimed to identify true SARS-CoV-2 vaccine reactions, underlying patient risk factors, and to confirm the safety of our vaccine challenge protocol for revaccination. METHODS: Patients with reported adverse first-dose SARS-CoV-2 vaccine reactions precluding second dose, or those with history of severe allergic reaction were given a graded vaccine challenge of an initial 10% dose, observed for 30 minutes, with advancement to the 90% dose if no concerning reaction. RESULTS: Of the 50 patients enrolled, 49/50 (98%) were able to obtain the full vaccine dose. 8 (16%) of patients had a first dose reaction concerning for delayed hypersensitivity, and 7/8 of those patients tolerated the full repeat vaccine dose. 42 (84%) patients had history of immediate reaction to the first dose of the vaccine and all tolerated the full dose via challenge protocol. 1/50 patients needed epinephrine, but was able to fully obtain the dose with outpatient treatment during the course, and subsequent revaccination. CONCLUSION: In a monitored setting, this challenge protocol is safe and effective for patients with history of adverse reaction to the vaccine or an underlying history of severe allergic reaction that would traditionally preclude repeat vaccination. The mechanism and pathophysiology of these reactions need to be elucidated through further research.