Omicron Breakthrough Infections in IMID Patients
October 4, 2022
Researchers in Amsterdam conducted a study to compare the severity of Omicron SARS-CoV-2 breakthrough infections in patients with immune mediated inflammatory diseases (IMID) versus healthy controls. IMID patients were invited to participate between April 2020 and March 2021, and were requested (but not obligated) to recruit a healthy control of same sex and similar age within a five year range. In total, 1882 patients with IMIDs and 708 health controls were included in the study.
Online questionnaires were distributed to participants for demographic and clinical data, and to document breakthrough infections four times within the designated time frame. “Breakthrough infections were classified as delta or omicron SARS-CoV-2 infections on the basis of publicly available data on the predominant circulating SARS-CoV-2 variant in the Netherlands at the time.”
431 IMID patients (23%) and 210 (30%) controls experienced a breakthrough infection, with 304 of 431 IMID patients and 142 of 210 controls having received a SARS-CoV-2 vaccine dose within 3 months of infection. Hospitalization was required by five IMID patients and in one healthy control. One IMID patient who experienced a breakthrough infection and was treated with anti-CD20 therapy died; three of the five hospitalized patients with a breakthrough infection were on anti-CD20 therapy generally.
Researchers found that “patients with immune-mediated inflammatory diseases are less frequently hospitalized when infected with the SARSCoV-2 omicron variant than with previous variants.” Researchers also found that a history of COVID-19 infection and a third vaccine dose were associated with a lower risk of experiencing breakthrough infection in both the control group and IMID patients.