WEDNESDAY, Oct. 6, 2021 (HealthDay News) -- The risk for breakthrough COVID-19 infections is increased for fully vaccinated patients with substance use disorders (SUDs), according to a study published online Oct. 6 in World Psychiatry.
Lindsey Wang, from the Case Western Reserve University in Cleveland, and colleagues examined the risk, time trends, outcomes, and disparities of COVID-19 breakthrough infection in fully vaccinated SUD patients from 14 days after vaccination completion. Data were included for 579,372 individuals (30,183 with a diagnosis of SUD and 549,189 without) who were fully vaccinated between December 2020 and August 2021.
The researchers found that the risk for breakthrough infection varied among SUD patients, from 6.8 percent for tobacco use disorder to 7.8 percent for cannabis use disorder, all significantly higher than the 3.6 percent in the non-SUD population. After adjustment for demographics and vaccine types, breakthrough infection risk remained significantly higher for all SUD subtypes, except tobacco use disorder, and was highest for cocaine and cannabis use disorder (hazard ratios, 2.06 and 1.92, respectively). After matching the groups for lifetime comorbidities and adverse socioeconomic determinants of health, the risk for breakthrough infection was increased only for cannabis use disorder (hazard ratio, 1.55). The risk for breakthrough infection was elevated for SUD patients who had received the Pfizer versus the Moderna vaccine (hazard ratio, 1.49).
"The overall risk of COVID-19 infection among vaccinated SUD patients was low, highlighting the effectiveness and the need for full vaccination in this population," the authors write. "However, our findings document that this group remains a vulnerable one even after vaccination."