Lewis Nelson, chair of emergency medicine at Rutgers New Jersey Medical School and an expert in addiction medicine, is available to comment on the National Institutes of Health’s announcement that vaccinated people with substance use disorders may be at higher risk for SARS-CoV-2 breakthrough infections and severe outcomes, including hospitalization and death, following breakthrough infections.

“Medical conditions, including substance use, raise the risk for contracting many infectious diseases. This new study documents that vaccination, while still protective, is less effective in people with substance use disorder, although much of the risk was accounted for by socioeconomic conditions such as housing and nutrition,” says Nelson. “However, those who smoked cannabis, even when controlling for socioeconomic characteristics, still had an increased risk of breakthrough infections. Even though this group tends to be younger, cannabis may have a specific adverse effect on lung or immune function.”