Retrospective study of association of COVID-19 vaccination with breakthrough infections and complication in cancer patients

Patients with cancer are known to have increased risk of COVID-19 complications, including death. A retrospective population-based cohort study in Ontario (Canada) evaluated the association of COVID-19 vaccination with breakthrough infections and complication in patients with cancer compared to noncancer controls.The study found that cancer patients had greater risk of SARS-CoV-2 infection and worse outcomes than controls. The risk was highest for patients with hematologic cancer and cancer patients receiving active treatment. Triple vacination was associated with lower risk of poor outcomes.