(HealthDay News) — During the omicron-predominant period, three doses of an mRNA COVID-19 vaccine were associated with improved protection against infection for patients receiving dialysis, but patients with low circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (RBD) immunoglobulin G (IgG) antibodies have increased infection risk, regardless of vaccination status, according to a study published online Aug. 15 in the Journal of the American Society of Nephrology.
Maria Montez-Rath, PhD, from Stanford University in California, and colleagues followed monthly semiquantitative SARS-CoV-2 RBD IgG index values in a randomly selected nationwide cohort of patients receiving dialysis. The relative risk for documented SARS-CoV-2 infection was estimated by vaccination and circulating RBD IgG during the omicron-dominant period of Dec. 25, 2021, to Jan. 31, 2022.
The researchers found that 25% of the 3,576 patients receiving dialysis received a third mRNA vaccine dose as of Dec. 1, 2022. Early antibody responses to the third dose were generally robust, with a median peak index IgG value of 150. SARS-CoV-2 infection was documented in 7% of patients during the study period. Patients without vaccination and with one or two versus three doses had a higher risk for infection. The risk for infection was higher among patients with circulating RBD IgG <23 versus IgG ≥23, irrespective of vaccine doses.
“Measuring a person’s circulating antibody response to SARS-CoV-2 virus may help us identify the highest risk persons eligible for enhanced protection among patients on dialysis, and other immunocompromised or frail populations,” a coauthor said in a statement.
Several authors disclosed financial ties to Ascend Clinical Laboratories.