UArizona-led study shows vaccinated people likely do not carry or spread virus

COVID-19 vaccination
Posted at 2:49 PM, Apr 01, 2021
and last updated 2021-04-01 17:49:56-04

TUCSON, Ariz. (KGUN) — Data from a real-world study released this week shows the Pfizer and Moderna vaccines are highly effective.

The University of Arizona's Mel and Enid Zuckerman College of Public Health was a key contributor to the CDC study of health care workers and first responders.

"We're very happy to see how effective these messenger RNA, these new types of vaccines, the Pfizer and Moderna, are against COVID-19," said Dr. Jeff Burgess, associate dean for research and professor at the College of Public Health.

The early data from an ongoing UArizona-led study confirms the findings of the phase three clinical trials. These COVID-19 vaccines are 90% effective against infection under real-world conditions.

Dr. Burgess and the College of Public Health has been following 3,000 health care workers and first responders in its AZ HEROES study. Once vaccinated, these essential workers take weekly COVID tests.

"This is real-world plus, because of the occupational hazards that our participants see on a day-in and day-out basis," Dr. Burgess said in a Zoom interview with KGUN 9.

The AZ HEROES study was funded by a $7.7 million CDC grant. The CDC study also used data from similar studies in other parts of the country.

The Moderna and Pfizer trials found the vaccines to be around 95% effective against COVID. The AZ Heroes study is much more comprehensive, also including the study of asymptomatic people.

The CDC has concluded, based on the findings, vaccinated people likely don't pose a risk of spreading the virus to those around them.

"They don't just protect the individual who's vaccinated, but they also prevent the spread of COVID-19 to other people," said Dr. Burgess. "This study really supports the use of the vaccine, not just to protect yourself, but to protect others as well."

The AZ HEROES study will continue for another 12 months. Dr. Burgess says there are several more questions that still need to be answered.

"If you get COVID-19 how long does your immunity last? We don't really know the answer to that question. Another important once is you're vaccinated, how long does the vaccine last? We also don't know the answer to that question as well. It's through studies like this where we can look at symptomatic and asymptomatic infection to effectively answer those questions."

Dr. Burgess is still looking for health care and frontline workers about to get the vaccine, to join the AZ HEROES study.