Skip to main content
You are the owner of this article.
You have permission to edit this article.
Mayo study of 3,000 vaccinated patients shows 80% reduction in COVID-19 contraction risk
top story

Mayo study of 3,000 vaccinated patients shows 80% reduction in COVID-19 contraction risk

  • 0

A new study from Mayo Clinic highlights the effectiveness of the two dose MRNA COVID-19 vaccines in contracting and spreading the disease.

Dr. Aaron Tande

Dr. Aaron Tande

The study, released March 11 and published in the medical journal “Clinical Infectious Diseases,” looked at Mayo patients who received screening tests between Dec. 17, 2020 to Feb. 8, 2021, in Wisconsin -- including La Crosse -- Minnesota and Arizona.

It found in those without coronavirus symptoms an approximately 80% reduction in risk of testing positive for COVID-19 10 days after their second and final dose of the Pfizer or Monderna vaccine.

Support Local Journalism

Your membership makes our reporting possible.

With the reduced risk of viral contraction comes a lessened chance of infectious spread from those who are positive and asymptomatic, the researchers note.

Researchers retrospectively reviewed a roster of 39,000 patients who had undergone routine pre-procedural or surgery molecular screening tests for COVID-19. Over 48,000 routine screening tests were conducted, including 3,000 on patients who had received at least one dose of the MRNA COVID-19 vaccine.

“We found that those patients without symptoms receiving at least one dose of the first authorized mRNA COVID-19 vaccine, Pfizer-BioNTech, 10 days or more prior to screening were 72% less likely to test positive,” says Dr. Aaron Tande, Mayo Clinic infectious diseases specialist and co-first author of the paper. “Those receiving two doses were 73% less likely, compared to the unvaccinated group.”

Emily Pyrek La Crosse Tribune

With adjustments made for age, sex, race/ethnicity, locality, healthcare system regions and other factors, the risk reduction for testing positive after both doses was deemed at 80%.

Emily Pyrek can be reached at

Concerned about COVID-19?

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Related to this story

Get up-to-the-minute news sent straight to your device.


News Alerts

Breaking News