New research has revealed that COVID-19 vaccines may not work as effectively in those whose immune systems have been negatively impacted by underlying medical conditions or the drugs used to treat those conditions.
These findings are not entirely surprising. For instance, previous investigations in immunocompromised people had pointed towards the possibility that vaccines may not perform optimally in these populations. In the VACANCE study of 2012, for example, less than half of the participants (who were cancer patients undergoing chemotherapy) produced antibodies to influenza after receiving the vaccine.
Based on these and other findings, scientists were seeking answers on whether similarly low immune responses would be observed when these vulnerable groups got the COVID-19 vaccination. So far, evidence is supporting this theory. A Johns Hopkins University study in which patients who were the recipients of organ transplants showed poor antibody responses to the Pfizer-BioNTech and Moderna vaccines—a mere 17% of the participants showed detectable levels of antibodies against SARS-CoV-2.
Similar results have also been reported in those with autoimmune conditions. Data published on the preprint server medRxiv indicated that on average, the participants who were on medications to manage chronic inflammatory diseases produced about one-third as many antibodies as healthy individuals who receive the COVID vaccine.
“CID patients treated with immunosuppressive therapies exhibit impaired SARS-CoV-2 vaccine-induced immunity, with glucocorticoids and B cell depletion therapy more severely impeding optimal responses,” wrote the authors.
For now, ways to improve immune responses for these at-risk groups are still being explored. Additional doses of the standard COVID vaccinations, mixing vaccines, or the use of monoclonal antibodies, have been proposed as possible solutions for protecting these patients.