Drug and alcohol abuse increase the risk of breakthrough COVID-19 infection as well as severe illness and death among fully vaccinated people, a new study shows.
"First and foremost, vaccination is highly effective for people with substance use disorders, and the overall risk of COVID-19 among vaccinated people with substance use disorders is very low," study co-author Dr. Nora Volkow, director of the U.S. National Institute on Drug Abuse, said in an institute news release.
She said it's important to encourage folks with drug and alcohol problems to get vaccinated and to acknowledge that even after they do, they have a higher risk of SARS-CoV-2 infection and must take steps to protect themselves.
For the study, the researchers analyzed electronic health records of nearly 580,000 people in the United States who were fully vaccinated against COVID-19 between Dec. 1, 2020 and Aug. 14, 2021, and who had not previously had COVID.
Seven percent of those with drug or alcohol problems had breakthrough infections, compared with 3.6% of those without substance use problems.
Infection rates ranged from 6.8% for tobacco users to 7.8% for those with cannabis use disorder.
Among people with substance use disorders who had a breakthrough infection, 22.5% were hospitalized, and 1.7% died, the study found. The rates were 1.6% and 0.5%, respectively, among people with drug and alcohol problems but no breakthrough infection.
The researchers also found that the risk of severe outcomes after a breakthrough infection was higher in patients with substance use disorders than in others.
The increased risk of breakthrough infections in people with substance use disorders appears to owe largely to coexisting health conditions and poor health linked to poverty, according to findings published Oct. 6 in the journal World Psychiatry.
"From previous studies, we knew that people with substance use disorders may be particularly vulnerable to COVID-19 and severe related outcomes," said study co-author Rong Xu, director of the Center for Artificial Intelligence in Drug Discovery at Case Western Reserve University in Cleveland.
"These results emphasize that, while the vaccine is essential and effective, some of these same risk factors still apply to breakthrough infections," Xu said in the release.
The U.S. Centers for Disease Control and Prevention has more on breakthrough infections.
SOURCE: U.S. National Institute on Drug Abuse, news release, Oct. 6, 2021