In vaccine clinical trials, the Pfizer and Moderna COVID-19 vaccines were shown to be about 95% effective in preventing COVID-19. Now a study from the Centers for Disease Control and Prevention uses real-world data to show that indeed, those who are 65 years and older who are fully vaccinated are 94% percent less likely to be hospitalized for COVID-19 than those who have not been vaccinated. Researchers enrolled hospitalized patients from 20 hospitals across the nation—including UCHealth University of Colorado Hospital.
Adit Ginde, MD, MPH, professor of emergency medicine, University of Colorado School of Medicine is the Colorado principal investigator of the study, which is the first large U.S. based multi-center study to evaluate how vaccines work in the real world.
“We focused on older adults because they are vulnerable to severe COVID-19 and because they were the first large group to receive the vaccine,” says Ginde, director of the Trial Innovation Network for the Colorado Clinical and Translational Sciences Institute and UCHealth emergency physician. “We compared hospitalized people with respiratory infections – some who had COVID and some who did not have COVID. Almost everyone hospitalized with COVID was not fully vaccinated.”
The study also showed that adults 65 and older who were partially vaccinated (receiving just one shot) were 64% less likely to be hospitalized with COVID-19 than people who had not received a vaccination. People are considered “fully vaccinated’’ two weeks after receiving their second dose of either the Pfizer or Moderna vaccines, both mRNA COVID-19 vaccines.
The results released by the CDC represent the first stage of a study that will continue to enroll patients nationwide and soon provide real-world data about the effectiveness of the vaccines against variants of the virus.
“Since we have published this study, we have enrolled another 1,300 people,” Ginde says. “The study will continue until we have enrolled at least 10,000 people. We will have data on different sub-populations and on different variants of concern.”
He explains that the virus of each hospitalized person who is COVID positive will be sequenced. This process will help identify variants. Researchers will use these data to study the effect of the mRNA vaccines on different variants.
| Michelle Howell, RN, BSN |
CU School of Medicine faculty are helping to operate the study, including David Douin, MD, a UCHealth anesthesia-critical care physician and Michael Tozier, MD, a hospitalist at UCHealth. Senior Professional Research Assistant Michelle Howell, RN, BSN is the project manager of the Colorado site, which has been recognized as a top contributor to the CDC study.
“We are currently the highest enrolling site in the network mostly because of Michelle’s leadership on the ground and high motivation from our staff and frontline clinicians,” says Ginde.
“We have a great team making this happen,” Howell says (pictured at left). “We all desperately want the pandemic to end and to get back to life as it was before masks and social distancing. In order to do that, we really need to know specific details about the different vaccines and how they work against the variants out there. This study will help us do that!”
Ginde wants to make sure people understand that those who are partially vaccinated are missing out on an important part of their protection. “It is not too late to get the second dose!” Ginde says.
He continues, “We see a number of patients in the hospital early after their first vaccine dose. Our results show that people have basically zero protection within 14 days after the first dose.”