The next possible AIDS vaccine

NewScientist is reporting that research from the Children's Hospital of Philadelphia has found an alternative vaccine method for preventing HIV infection. Using a virus to produce antibodies in the muscle - bypassing the immune system altogether and avoiding the cells that HIV infects.

They followed up on 9 macaques who were vaccinated and then exposed to SIV (the simian AIDS virus) over 85 weeks (roughly a year and half). None have been found to be infected. The control group was not vaccinated but exposed to SIV - 4 of the 6 monkeys have died of simian AIDS.

They hope that it makes it to the clinic, adjusted for HIV as opposed to SIV, in 2-3 years.

The issues I foresee being potential downfalls are:

  • The length of protection by the injection - how long are the antibodies produced? How often is re-injection needed? How long does protection last (do the antibodies remain or are they transient)? It uses gene insertion, but as foreign DNA is it accepted indefinitely?
  • The specificity of the antibodies for HIV as opposed to a less specific response (possibly even triggering autoimmunity or an immune reaction against the antibodies themselves - though the host muscle is producing the proteins so this isn't likely, it should still be examined)
  • Which HIV strains will it cover? And will it be effective with co-infection?
  • What is the long-term affect on the muscle?How specific is the gene insertion?

The researchers seem aware that this isn't a sure thing...yet. But it's a promising step forward in a battle against a disease that seems to be never-ending.

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