New research co-authored by Prerak Juthani ’22, a joint-degree student at the Yale School of Management and the Yale School of Medicine, has yielded important insights into breakthrough COVID-19 cases among fully vaccinated individuals, as well as their risk of serious illness.
The study, authored by a team of Yale researchers, was published September 7 in The Lancet. Focusing on a cohort of hospitalized patients in the Yale New Haven Health System, the study identified 969 individuals who tested positive for the COVID-19 infection during a 14-week period. Of the group, 54 were fully vaccinated.
Researchers found that more than one quarter of the 54 patients developed severe disease. These patients were older, between 65 and 95 years old, and suffered from preexisting comorbidities, such as heart disease and diabetes. The majority of vaccinated patients experienced mild symptoms or none at all.
The study, researchers conclude, illustrates the powerful protective benefits of vaccination in breakthrough cases.
Juthani became involved with the research through his mentor and friend Dr. Akash Gupta, a resident at Yale New Haven Hospital and co-lead author of the study. Gupta was assisting Dr. Hyung Chun, associate professor of medicine and senior author of the study. Juthani, also a co-lead study author, helped collect data.
Juthani said that he was surprised by the local and national media attention the study has received.
“It’s great to see our work being used to guide public messaging during the pandemic,” Juthani said. “However, one thing that I want to stress is that while our research focuses on breakthrough infections, only 54 of the 969 COVID-positive patients we looked at were true breakthrough cases. The remaining 915—or 94%—were not fully vaccinated. This demonstrates again that these vaccines are insanely effective. Please get the vaccine!”