in taxon negatively regulates negative regulation of immunoglobulin production negative regulation of immunoglobulin mediated immune response isotype switching regulation of isotype switching negative regulation of isotype switching negative regulation of isotype switch recombination GO:0045829 Any process that stops, prevents, or reduces the frequency, rate or extent of isotype switching. inhibition of isotype switching down regulation of isotype switching down-regulation of isotype switching downregulation of isotype switching negative regulation of class switch recombination negative regulation of class switching negative regulation of DNA recombination negative regulation of B cell activation negative regulation of developmental process biological regulation Gnathostomata <vertebrates>