SIV is a virus which causes AIDS in monkeys this virus is similar to HIV virus but infects only monkeys,
A vaccine is successfully tested in a research trail which successfully protected monkeys from getting infected with SIV, even after a year after vaccination upon challenging these monkeys with load of SIV infection.
This research was undertaken to develop an approach for developing a vaccine against HIV and AIDS. Similar approach now can be used or applied for developing a vaccine for HIV, and can be used for the people who are at greater risk of getting HIV infection.
How vaccine was developed?
Louis Picker, M.D., associate director of the OHSU Vaccine and Gene Therapy Institute made use of a virus to deliver gen in the T cells of monkeys which code for proteins which produced SIV viral proteins which imparted memory for T lymphocytes for producing antibodies against SIV which completely neutralize Subsequent SIV infection in monkey.
Cytomegalovirus CMV was genetically engineered to express SIV proteins which could sensitize immune system and produce antibodies against SIV which are able to attack and neutralize actual SIV infection even after one year.
Monkeys were given this vaccine and were challenged with SIV infection; initially SIV appeared in blood but subsequently disappeared from blood, as well as from other body tissue cells.
HIV viral load can be reduced with drug therapy but HIV virus cannot be eliminated permanently from body, it is just possible only when a approach which make use of a drug or antibodies which attack on HIV Immediately after entry of HIV in human body.
Above model SIV vaccine development can be used for developing similar vaccine against HIV.