If you smoke tobacco or marijuana frequently, if you’re addicted to alcohol or opioids, you’re more likely to experience breakthrough COVID-19 – or getting the virus even after you’re vaccinated, a new study shows.
The national study from researchers at Case Western Reserve University in Cleveland also shows that co-occurring health conditions and adverse socioeconomic health factors, which are more common in people with substance use disorders than those without, are largely responsible for the greater risk of breakthrough infections.
“Overall, people with substance use disorder have a high risk of getting COVID-19,” said lead author Rong Xu, professor of biomedical informatics and director of the Center for Artificial Intelligence in Drug Discovery at the Case Western Reserve School of Medicine. “The risk of breakthrough infection is also higher.”
And those with substance use disorders also had higher rates of hospitalization and death, after breakthrough infections.
“These results emphasize that the same risk factors that affected COVID-19 severity before vaccine was available are still risk factors in breakthrough infections,” said Pamela Davis, dean emerita and Arline and Curtis Garvin Research professor at Case Western who is another of the study’s lead authors. “This means that care for ongoing conditions aside from COVID-19 remains very important for both patients and physicians to reduce overall disease morbidity.”
Xu said COVID-19 vaccines are “highly effective” and people with substance use disorders should get vaccinated.
Addiction specialists in the Cincinnati area are encouraging their patients to do that and to maintain treatment for all of their health issues.
“I’m pretty blatant and upfront,” said Dr. Mina “Mike” Kalfas, an addiction specialist with Journey Recovery Center in Northern Kentucky. “If it’s someone I know, I start off with, ‘Did you get your vaccine yet?’ I’ve always done the same for flu shots, too.”
Kalfas treats people with opioid use disorder but also methamphetamine, cocaine and other addictions. Those suffering from long-term addictions often have life circumstances that coincide with risk for the virus, he said. Here’s why:
- They often live in close quarters (recovery houses, for example).
- They congregate in meetings often in small rooms or cramped spaces.
- The jobs they often can get are in factories, retail, food service – jobs that have higher exposure risks.
- They may be intermittently incarcerated, which Kalfas called “a breeding ground” for sharing a highly contagious virus.
- They often come in with misconceptions or even false beliefs about vaccines and COVID-19.
Dr. Roberto Soria, chief medical officer of the Crossroads Center, a methadone clinic in Corryville, said the risks for those with opioid use disorder are great for an abundance of reasons. He too has been working to get his patients vaccinated. “Those that have not been vaccinated yet are the difficult ones to convince,” he said. He also said that, based on medical literature, he believes people who have substance use disorders “should receive the booster vaccine.”
Neither the researchers nor Cincinnati area specialists were surprised by the findings of the study, which was funded by the National Institute of Drug Abuse.
“This result is kind of our hypothesis,” Xu said. “People with SUD (substance use disorder) often have a lot of comorbidities. They have a lower immune resistance. They also have co-occurring diseases.”
The researchers analyzed nearly 580,000 electronic health records nationwide from people with and without substance use disorders who were fully vaccinated against COVID-19 between Dec. 1, 2020, and Aug. 14, 2021, and who had not been infected before vaccination, Case officials said.
They identified the proportion of people in each group who contracted COVID-19 at least two weeks after their final vaccination. They repeated the analysis after matching patients with and without substance-use disorders for demographic characteristics, socioeconomic factors that influence health, such as housing or employment instability, and lifetime physical illnesses, such as high blood pressure, heart disease, obesity, or diabetes, the research shows. The team also looked at whether fully vaccinated people with breakthrough infections had a different risk for hospitalization and death, compared with matched people without breakthrough infections.
They found that the risk of breakthrough infections was “significantly higher” in those with substance use disorders than in those without. Seven percent of vaccinated people with addictions had a breakthrough infection during the study compared with 3.6% of people without substance use disorders.
The risk varied slightly among people with different addictions, ranging from 6.8% for people who use tobacco to 7.8% for those who use marijuana.
The researchers also noted that when co-occurring diseases and adverse socioeconomic characteristics were controlled for, people with most substance-use disorders no longer had the higher rates of breakthrough infections. “The exception was people with marijuana-use disorder, who still were 55% likely to experience breakthrough infections as people without substance-use disorders, even though they tended to be younger and had fewer co-occurring health conditions,” Case officials said in a release about the report. “The authors hypothesized that factors such as adverse effects of marijuana on lung and immune function may have contributed to the higher risk for breakthrough infection in this group.”
The doctors recommend vaccines, but also support the Centers for Disease Control and Prevention guidelines for masking and distancing to decrease the chance of getting COVID-19.