Antibody Responses to Third-Dose mRNA Vaccines in Nursing Home and Assisted Living Residents

A third-dose COVID-19 vaccination was recommended in US long-term care settings on September 24, 2021,1 though only half of eligible nursing home residents have received a third dose as of December 5, 2021.2 On August 17, 2021, the province of Ontario, Canada, was relatively early to recommend a third-dose mRNA vaccination for residents in nursing home and assisted living settings in response to waning protection.3 Early real-world vaccine effectiveness data suggest substantially greater protection from Omicron (B.1.1.529; hereafter Omicron) infection for persons who have received a third-dose mRNA vaccine, compared with a 2-dose vaccination series.