Addiction increases risk of COVID breakthrough: study

WASHINGTON (SBG) — Health experts recognized early in the pandemic that people who abuse drugs and alcohol had a higher risk of contracting COVID-19 and experiencing more severe outcomes. New research shows that those vulnerabilities remain even after those individuals have been vaccinated.

According to a new study in the journal World Psychiatry, people with substance use disorders (SUD) were almost twice as likely to have breakthrough COVID infections than those without the condition.

Researchers at Case Western University and the National Institute on Drug Abuse (NIDA), looked at the outcomes for 30,183 vaccinated people with alcohol, tobacco, cannabis, cocaine and opioid use disorders compared to nearly 580,000 vaccinated patients across the United States without a substance use disorders. They found roughly 7% of vaccinated people who abused drugs and alcohol contracted the virus, compared to 3.6% of the other patients.

Underlying addiction problems also dramatically increased the likelihood of hospitalization. Typically, breakthrough infections among vaccinated people are mild. Only 1.6% of general patients required hospitalization and 0.5% died. Among people with substance use problems, 22.5% required hospitalization and 1.7% died.

"People understand that obesity, Type 2 diabetes, heart disease [are risk factors],"explained QuanQiu Wang, a co-author of the study and specialist at the Center for Artificial Intelligence in Drug Discovery at Case Western Reserve University. "Our study shows people with substance abuse disorder are also a very vulnerable population for COVID-19 infections as well as severe outcomes."

Even though the risk of infection is elevated, researchers emphasized the breakthrough cases were rare and the vaccination was over 90% effective among this group.

The study also showed the potential for infection varied depending on the substance. People addicted to cocaine and marijuana were at the highest risk of getting breakthrough infections than a comparable population that didn't use those drugs. Tobacco users experienced a 6.8% greater risk of breakthrough infections, opioids were 7.1%, alcohol was 7.2% and cocaine was 7.7%.Marijuana abuse had the highest incidence of breakthroughs cases with 7.8% of that cohort getting infected.

In most cases, the study suggests that the increased risk was related to health conditions associated with addiction. Across the board, patients with substance abuse disorders had significantly higher incidents of lifetime medical conditions, including heart, lung, liver and kidney disease, organ transplants and immunological diseases.

The only exception was for people with cannabis addiction. People who abused marijuana were 55% more likely to experience breakthrough infections, despite users typically being younger and having fewer underlying health conditions.

Researchers were unclear why marijuana had that effect. "We don't know the mechanism," Wang said, noting it could be an effect of the drug on the pulmonary system.

Beyond the underlying health issues caused by substance abuse, addiction could be an independent factor that makes people more susceptible to infection. Researchers found that breakthrough infections occurred more frequently in people who were recently hospitalized or saw a doctor because of their addiction.

"The higher rate of breakthrough infection in active SUD patients might in part be due to behaviors that place them in situations of greater infection risk, or to the effects of the drugs, such as respiratory depression with opioid consumption or the adverse impact of cannabis on immune function," the paper stated.

Millions of Americans struggle with addictions. Nearly 11% of the U.S. population have struggled with drug abuse at some point. Another 5.3% of Americans currently live with alcohol abuse disorder.

The authors of the study emphasized the importance of vaccination for people whose health may already be compromised due to drug or alcohol use. Wang encouraged masking and booster shots. The Centers for Disease Control and Prevention currently recommends boosters for those over 65 and adults who are at high risk of severe complications.

"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," said Dr. Nora D. Volkow, director of NIDA.

If you or someone you know is in need of help for a substance use disorder call SAMHSA’s National Helpline at 1-800-662-HELP or visit their website, here.