DULUTH, Minn. (KTTC) -- A "real world" study was conducted in eight places that tested vaccine efficacy for asymptomatic cases in first responders and essential healthcare workers. One of those eight places was in Duluth.
Those participating in the study, 448 total, would send a weekly nose swab to labs in Duluth for COVID testing. The study took all the individuals and looked at those fully vaccinated, partially vaccinated and unvaccinated. Throughout the study in Duluth, 12 people were infected with COVID-19 or 2.7 percent.
The federal study of vaccine efficacy ran from December 2020 through March 2021.
Researchers found from the eight sites, that the two mRNA vaccines of Pfizer and Moderna were both 90% effective at preventing asymptomatic cases of coronavirus.
The vaccines were also 80% effective after a single dose.
"Previously, we knew that it was effective against symptomatic infection but this means there's no people walking around as vectors or silent carriers of infection after being vaccinated," said Dr. Harmony Tyner, an Infectious Disease Specialist with St. Luke's Hospital in Duluth who was part of the study.
Now that researchers and health officials know that both two-dose vaccines are so effective against COVID-19, could they be the key to unlocking change in policies and health guidance?
"I think this is fantastic news and this might have policy implications for social distancing recommendations after being vaccinated," Tyner said.
"That is part of what in turn leads to evolution of guidance documents that are coming from CDC and what we're talking about in public health," said Olmsted County Public Health Director Graham Briggs.
Which may be why after the study was published by the Centers for Disease Control and Prevention, the center changed its stance on domestic travel for those fully vaccinated last week.
However, health officials and researchers aren't ready to declare huge changes just yet even as more data comes out.
"We get more and more comfortable as these studies come out that we're not seeing the spread in vaccinated individuals and we're not seeing asymptomatic spread," said Briggs.
However, data will continue to be collected.
"We'll keep on collecting data and hopefully come up with answers to be able to do those things again safely," said Tyner.
Johnson and Johnson's single-dose vaccine was not a part of this study however studies continue on that particular vaccine.
Click here to view the full study.