Paragraph 2: HIV antibodies themselves aren’t rare, and scientists regularly find ones that are effective against a few different strains. But until last year, the most powerful antibody found only protected against about 40% of strains. New techniques for rapidly identifying antibodies have changed this, and sparked an unprecedented number of breakthroughs: in the past year, about half a dozen broadly neutralizing antibodies have been identified. These new antibodies are extremely potent (they neutralize the virus at low blood concentrations) and protect against many more strains of HIV. The research was published as two separate papers in Science (found here and here).
Originally Posted by 78704
Yes, and even those antibodies, while broadly effective, neutralize 91% of HIV strains. Therefore, 9% of strains would not be neutralized and could easily become the basis of new basis of HIV infections fairly rapidly.
Paragraph 7 speaks more to vaccine development. Vaccines aren't made by injecting someone else's antibodies into you. Your body may actually make antibodies to foreign antibodies injected into you, if your immune system identifies them as "non-self." Vaccines induce the production of antibodies in the vaccinated person by simulating some feature (an antigen, usually a protein), found on the surface on an infectious organism (bacteria, virus) in a way that activates the vaccinated person's immune system to produce antibodies which will bind to that surface antigen and interfere with the organism's ability to infect as well as flag the infectious organism for destruction by white blood cells.
The problem with prior attempts at an HIV vaccine is that they have focused on a surface antigen complex called gp120 which is hidden in a depression/pocket on the surface of the virus. When the HIV particle infects a T4 helper cell the gp120 complex "pops up" and participates in attaching to the T4 cell and allows for the virus to inject it's RNA into the cell, infecting it. While antibodies for gp120 are easy to find, the virus easily mutates defenses, typically "learning" to hide the gp120 complex from the immune system's antibodies with smaller glycoproteins (basically small sugar coated protein fingers) which obscure the pocket/depression that the gp120 complex resides in denying access to the antibodies but do not prevent gp120 from "popping up" when it's time to infect.
The promise of these newly isolated antibodies is that they seem to recognize other previously
unrecognized, unidentified, unstudied protein complexes/antigens on the viral surface that do not change or mutate nor are they hidden in a pocket or depression, though it doesn't look like they necessarily participate in binding to and infecting the T cells. So, they represent a non-shifting target on the virus. But like I said, the trick is to trick the immune system into recognizing these antigens.
What these new antibodies provide hope for is the possibility (still not an easy slam-dunk) to reverse-engineer the shape of whatever these antigen structures look like and develop a non-infectious soup of these novel,
previously unidentified, antigens in isolation that can be injected and hopefully result in getting the vaccinated individual to stimulate production of their own broad-strain effective antibodies. But one has to question
why other infected people besides these exceptional individuals
don't already produce their own antibodies to these unchanging structures since they're
supposed to be
already present on the HIV strains they're infected with. There's some degree of finger-crossing and good wishes involved in actually expecting or predicting that a vaccine based on supranormal quantities of these stable antigens will reliably stimulate the production of similarly broadly-effective antibodies in the general population. If the genes coding for these antibodies simply aren't present in most individuals in the population, then it may be required to administer widespread gene therapy to insert the genes into the population to make such a vaccine even viable in the first place. People freak out over genetically engineered tomatoes so I'd be interested in seeing how asking people to allow themselves to be basically genetically engineered to avoid HIV infection goes over when they can try condoms and being monogamous instead. The irony would be that it would require basically artificially infecting the B cells (which produce antibodies) with the new genes and hoping the gene transfection would remain stable. In cell culture gene transfection studies, the inserted gene can sometimes "fall out" and no longer be expressed. But this is sort of getting off the subject since researchers haven't even demonstrated that they can successfully reverse engineer the shape of these stable target antigens from shape of the antigen binding sites on these broadly effective antibodies.
The only other alternative is to use weakened HIV to try and develop a vaccine but that would be tantamount to suicide for the subjects and unethical. It's also not possible to use dead virus to raise a vaccine. That's been tried. Dead or inactivated HIV has been found to lose antigenicity (they lose the ability to stimulate antibody production to live HIV) presumably because they degrade rapidly and the surface antigens lose their resemblance to the "live" forms.
Still, even if a vaccine is developed from these novel antibodies and 9% of HIV strains aren't recognized, you still will allow for those 9% of HIV strains to go merrily along unimpeded and produce new infections which will not only spread but will also be vaccine-resistant and that much harder to develop a new vaccine against.
