A vaccine that is capable of delivering a double whammy against AIDS-causing human immunodeficiency virus by both providing immunity against the infection while at the same time destroying cells infected by the virus is ready for clinical trials, a group of Russian researchers announced today.
The team from Vector State Scientific Center of Virology and Biotechnology, Kol’tsovo, Novosibirsk first reported their research on the CombiHIVvac in the journal Doklady Biochemistry and Biophysics in May 2007.
The vaccine is an artificial virus-like particle whose outer casing consists of the TBI (T- and B cell epitopes containing immunogen) protein constructed by the researchers combined with the polyglucin protein.
This protein contains nine components stimulating different cells of the immune system: both the ones that produce antibodies and the ones that devour the newcomer.
The DNA coding the TCI (T-cell immunogen) protein is contained inside the protein casing.
The protein contains more than 80 HIV proteins fragments selected in the optimal way, which should activate the immune system.
The researchers have selected only conservative fragments -- the ones that remain constant in the course of all major changes of HIV-1 and will certainly be noticed by the immunized organism there by enabling the immune system to catch the virus even if it changes its form to “hide” from the immune system.
The coating and the filling of the particle represent independent vaccines, which cause specific cellular and humoral immune responses.
In the assembled form, the combiHiVvac vaccine is a particle 40 to 100 nanometers in diameter, approaching in size to the HIV-1 virus.
The antibodies which are formed inside immunized mice under the action of vaccine recognize the real HIV-1 proteins and neutralize the virus.
This was shown by the experiments on the cell culture infected by the virus and processed by mice’s antibodies.
Preclinical trial findings allow to hope that the combiHIVvac vaccine will effectively fight even against modified HIV-1 variants.
The new vaccine is nontoxic as even a fivefold dose does not cause organs damage.
Repeated injections reinforce inflammatory processes in the livers afflicted by other conditions.
The combiHIVvac vaccine does not cause autoimmune diseases or anaphylactic reactions, and it does not weaken the organism tolerance to infections either.
The scientists emphasize that as the combiHIVvac vaccine not only stimulates antibody production but also destroys the cells infected by the virus, this vaccine can be considered not only a prophylactic one but also as a therapeutic one.
The vaccine they developed is ready for clinical trials, the researchers declared.