IgG antibodies confer sterilizing protection to SHIV-infected macaques.

2004 FEB 4 - (NewsRx.com & NewsRx.net) -- Transfer of neutralizing IgG antibodies to macaques 6 hours (but not 24 hours) after SHIV infection conferred sterilizing protection.

According to a study from the United States, "Passive transfer of high-titered antiviral neutralizing IgG, known to confer sterilizing immunity in pig-tailed monkeys, has been used to determine how soon after virus exposure neutralizing antibodies (NAbs) must be present to block a simian immunodeficiency virus (SIV)/HIV chimeric virus infection."

"Sterilizing protection was achieved in three of four macaques receiving neutralizing IgG six hours after intravenous SIV/HIV chimeric virus inoculation as monitored by PCR analyses of and attempted virus isolations from plasma, peripheral blood mononuclear, cell, and lymph node specimens," reported Yoshiaki Nishimura and collaborators at the National Institute of Allergy and Infectious Diseases and the University of Washington (Seattle). "In the fourth animal, the production of progeny virus was suppressed for more than four weeks. A delay in transferring NAbs until 24 hours after virus challenge resulted in infection in two of two monkeys."

"These results suggest that even if a vaccine capable of eliciting broadly reactive NAbs against primary HIV-1 were at ...