COVID-19 mRNA revaccination is safe and well tolerated in individuals with previous adverse reactions to the vaccine and/or long COVID.

BACKGROUND

Vaccine safety is a primary concern among those with a history of adverse reactions to coronavirus disease 2019 (COVID-19) mRNA vaccines. Retrospective data and cohorts of individuals with severe previous reactions suggest that revaccination is safe and well tolerated. However, prospective data are limited.

OBJECTIVE

We sought to prospectively assess safety and tolerability of COVID-19 mRNA vaccines in individuals with a history of adverse vaccine reactions and in individuals with long COVID.

METHODS

Adults with a self-reported adverse reaction to COVID-19 mRNA vaccination and/or long COVID underwent COVID-19 mRNA revaccination at the University of Michigan with 30-minute observations. Participants were contacted by telephone after 7 days to review interval adverse events.

RESULTS

A total of 103 participants received COVID-19 mRNA revaccination-91 with history of adverse vaccine reaction, 20 with long COVID, and 8 with both. Mean age at enrollment was 41.8 years, and women were 67% of the cohort. Five individuals (4.9%) developed immediate symptoms with revaccination. All 5 events were mild (Consortium for Food Allergy Research severity level 1). Vital signs were assessed prevaccination and 30 minutes postvaccination. At 7-day follow-up, 77% of participants reported at least 1 adverse event, with fatigue (33.7%), headache (29.7%), and muscle pain (28.7%) most commonly reported. No follow-up reactions were severe. Five of the 103 participants had incidentally elevated baseline serum tryptase. None of these participants experienced immediate symptoms with revaccination.

CONCLUSIONS

Revaccination with COVID-19 mRNA vaccines was safe and well tolerated among individuals with previous adverse COVID-19 mRNA vaccine reaction and/or long COVID.