Rg. Fisher et al., Passive IgA monoclonal antibody is no more effective than IgG at protecting mice from mucosal challenge with respiratory syncytial virus, J INFEC DIS, 180(4), 1999, pp. 1324-1327
Respiratory syncytial virus (RSV) is a mucosally restricted pathogen that c
an cause severe respiratory disease. Although parenteral administration of
sufficient RSV-specific IgG can reduce severity of lower respiratory tract
infection in high-risk infants, delivery of antibody by direct airway admin
istration is an attractive alternative. Topical and parenteral administrati
on of an IgA monoclonal antibody (MAb) specific for the RSV F glycoprotein
was compared with an IgG MAb, specific for the same antigenic site, for abi
lity to protect mice against RSV infection. Administration of RSV-specific
IgG was more effective in reducing RSV titers in lung (4.6 log(10) pfu/g) t
han IgA MAb (3.6 log(10) pfu/g) when given intranasally immediately prior t
o infection (P = .005), RSV titers in the nose were reduced only by prophyl
actic administration of IgG parenterally, Therefore, topical administration
of IgA is no more effective than topically administered IgG and is less ef
fective than systemically administered IgG for protecting against RSV infec
tion.