The distribution of casirivimab and imdevimab was stopped in January of 2022 because of a lack of efficacy against SARS-CoV-2 variants. Imdevimab is a monoclonal antibody given together with casirivimab. Both are directed against the SARS-CoV-2 virus that causes COVID-19. Casirivimab and imdevimab transiently increased anti-receptor-binding domain IgG titers in one woman. Because imdevimab is a large protein molecule, the amount in milk is likely to be very low.[1] It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal.[2]