Real-time analysis of a mass vaccination effort confirms the safety of FDA-authorized mRNA COVID-19 vaccines

Reid McMurry, Patrick Lenehan, Samir Awasthi, Eli Silvert, Arjun Puranik, Colin Pawlowski, A. J. Venkatakrishnan, Praveen Anand, Vineet Agarwal, John C. O'Horo, Gregory J. Gores, Amy W. Williams, Andrew D. Badley, John Halamka, Abinash Virk, Melanie D. Swift, Katie Carlson, Deeksha Doddahonnaiah, Anna Metzger, Nikhil KayalGabi Berner, Eshwan Ramudu, Corinne Carpenter, Tyler Wagner, Ajit Rajasekharan, Venky Soundararajan

Research output: Contribution to journalArticlepeer-review


Background: As the coronavirus disease 2019 (COVID-19) vaccination campaign unfolds, it is important to continuously assess the real-world safety of Food and Drug Administration (FDA)-authorized vaccines. Curation of large-scale electronic health records (EHRs) enables near-real-time safety evaluations that were not previously possible. Methods: In this retrospective study, we deployed deep neural networks over a large EHR system to automatically curate the adverse effects mentioned by physicians in over 1.2 million clinical notes between December 1, 2020 and April 20, 2021. We compared notes from 68,266 individuals who received at least one dose of BNT162b2 (n = 51,795) or mRNA-1273 (n = 16,471) to notes from 68,266 unvaccinated individuals who were matched by demographic, geographic, and clinical features. Findings: Individuals vaccinated with BNT162b2 or mRNA-1273 had a higher rate of return to the clinic, but not the emergency department, after both doses compared to unvaccinated controls. The most frequently documented adverse effects within 7 days of each vaccine dose included myalgia, headache, and fatigue, but the rates of EHR documentation for each side effect were remarkably low compared to those derived from active solicitation during clinical trials. Severe events, including anaphylaxis, facial paralysis, and cerebral venous sinus thrombosis, were rare and occurred at similar frequencies in vaccinated and unvaccinated individuals. Conclusions: This analysis of vaccine-related adverse effects from over 1.2 million EHR notes of more than 130,000 individuals reaffirms the safety and tolerability of the FDA-authorized mRNA COVID-19 vaccines in practice. Funding: This study was funded by nference.

Original languageEnglish (US)
Pages (from-to)965-978.e5
Issue number8
StatePublished - Aug 13 2021


  • BNT162b2
  • COVID-19
  • COVID-19 vaccines
  • Translation to population health
  • mRNA-1273
  • propensity score matching
  • real world analysis
  • vaccine safety

ASJC Scopus subject areas

  • General Medicine


Dive into the research topics of 'Real-time analysis of a mass vaccination effort confirms the safety of FDA-authorized mRNA COVID-19 vaccines'. Together they form a unique fingerprint.

Cite this