An analysis of electronic health records of nearly 580,000 fully vaccinated people in the United States found that while the risk of SARS-CoV-2 breakthrough infection among those with substance-use disorders was low overall, it was higher for people who misuse substances such as alcohol, tobacco, marijuana and opioids.
The study, led by researchers at Case Western Reserve University and the National Institute on Drug Abuse (NIDA)—part of the National Institutes of Health—was published in World Psychiatry.
The study also determined that co-occurring health conditions and adverse socioeconomic factors of health—more common in people with substance-use disorders—appear to be largely responsible for the increased risk of SARS-CoV-2 breakthrough infections. People with substance-use disorders also had elevated rates of severe outcomes, including hospitalization and death, following breakthrough infections.
“With the dominance of the Delta variant, waning vaccine immunity and high comorbidity burden in the U.S. population—six in 10 adults have a chronic disease—it is important to continuously evaluate the effectiveness of COVID-19 vaccines and the long-term effects of COVID-19,” said Rong Xu, a professor of biomedical informatics and director of the Center for Artificial Intelligence in Drug Discovery at the Case Western Reserve School of Medicine and a senior author on the study.
Previous analyses conducted in the early stages of the pandemic found that people with substance-use disorders were at increased risk of SARS-CoV-2 infection. They also were more likely to have severe disease requiring hospitalization or resulting in death. This was particularly true for Black people with a substance-use disorder, the researchers concluded.