Patients with substance use disorder at higher risk for breakthrough SARS-CoV-2 infections
The risk for a breakthrough SARS-CoV-2 infection was significantly higher among patients with a substance use disorder than those without one, a population-based cohort study showed.
Still, researchers said the risk for a breakthrough SARS-CoV-2 infection was low, even among people with substance use disorder (SUD).
“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,” Rong Xu, PhD, a professor of biomedical informatics and director of the Center for Artificial Intelligence in Drug Discovery at the Case Western Reserve School of Medicine, said in a press release.
Xu and colleagues reviewed data from 579,372 fully vaccinated adults in the U.S. who had not been diagnosed with COVID-19 prior to vaccine administration. Of that total, 30,183 had a diagnosis of SUD. Among all patients, the majority received the Pfizer-BioNTech COVID-19 vaccine (75.6%), followed by the Moderna vaccine (21.1%), then the Johnson & Johnson vaccine (3.3%).
Xu and colleagues reported that the risk for breakthrough SARS-CoV-2 infection among patients with SUD fluctuated depending on the substance. The overall risk was 6.8% for those with tobacco use disorder, 7.1% for those with opioid use disorder, 7.2% for those with alcohol use disorder, 7.7% for those with cocaine use disorder and 7.8% for those with cannabis use disorder. Conversely, the risk for breakthrough infection was 3.6% among those without SUD.
After adjusting the data for factors including age, sex, ethnicity and vaccine type, the breakthrough infection risk was highest for cocaine use disorder (HR = 2.06; 95% CI, 1.3-3.25) and cannabis use disorder (HR = 1.92; 95% CI, 1.39-2.66). When the researchers matched all patients regardless of SUD status for “lifetime comorbidities and adverse socioeconomic determinants of health,” only those with cannabis use disorder had a higher risk for a breakthrough infection (HR = 1.55; 95% CI, 1.22-1.99).
The risk for hospitalization among the patients with SUD was 22.5% in the breakthrough infection group and 1.6% in the non-breakthrough infection group (RR = 14.4; 95% CI, 10.19-20.42). The risk for death among those with SUD was 1.7% in the breakthrough infection group and 0.5% in the non-breakthrough infection group (RR = 3.5; 95% CI, 1.74-7.05).
“These data suggest that fully vaccinated SUD individuals are at higher risk for breakthrough COVID-19 infection, and this is largely due to their higher prevalence of comorbidities and adverse socioeconomic determinants of health compared with non-SUD individuals,” the researchers wrote.
National Institute of Drug Abuse Director and study co-author Nora D. Volkow, MD, noted in a press release that the vaccines were “highly effective” in patients who have SUD, and that the overall risk for COVID‐19 among patients with SUD who are fully vaccinated was “very low.”
“We must continue to encourage and facilitate COVID-19 vaccination among people with substance use disorders, while also acknowledging that even after vaccination, this group is at an increased risk and should continue to take protective measures against COVID‐ 19,” she said.
The findings build on previous research published in Molecular Psychiatry regarding a link between SUD and COVID-19. In that study, researchers conducted a retrospective review of electronic health record data from 73,099,850 patients, most of them aged between 18 and 65 years, white and female. Among all patients studied, 7,510,380 had been diagnosed with SUD at some point in their lives, 722,370 had been diagnosed with SUD in the past year, 12,030 patients were diagnosed with COVID-19 and 1,880 patients had SUD and COVID-19 diagnoses at some point in their lives.
The study showed that those who were diagnosed with SUD within the past year had a significantly increased risk for COVID-19 compared with those who were not recently diagnosed with SUD (adjusted OR [aOR] = 8.699; 95% CI, 8.411-8.997). Among those with an SUD diagnosis in the past year, African American patients had a significantly higher risk than Caucasian patients (aOR = 2.173; 95% CI, 2.01-2.349). The researchers wrote that their results underscore the importance of screening and treating “individuals with SUD as part of the strategy to control the pandemic while ensuring no disparities in access to health care support.”
People with substance use disorders may be at higher risk for SARS-CoV-2 breakthrough infections. https://www.nih.gov/news-events/news-releases/people-substance-use-disorders-may-be-higher-risk-sars-cov-2-breakthrough-infections. Published Oct. 6, 2021. Accessed Oct. 7, 2021.