In an opinion piece posted online Anthony Fauci, director of the National Institutes of Health's National Institute of Allergy and Infectious Diseases, addressed head-on the question, Why after nearly 30 years is there still no vaccine against HIV?
'It's a very reasonable query, given the extraordinary successes in vaccine development for other serious diseases over the years,' Fauci wrote. 'Highly effective vaccines have been developed for many other viral diseases, including polio, measles, mumps, rubella, hepatitis A, hepatitis B, influenza, rabies, varicella, human papillomavirus, rotavirus, yellow fever, and Japanese encephalitis. One viral infection -- smallpox -- has been completely eradicated from the human population.'
But HIV has proved to stymie researchers largely because scientists have yet to discover any way to make the immune system resistant to the virus. Use of weakened bacteria or virus, which is the basis for most other effective disease vaccines, is not an option, since it could lead to systemic HIV infection. And as yet researchers have found no other alternative approach to priming the immune system to recognize and destroy HIV.
'Unlike classical vaccinologists, HIV vaccine scientists must learn how to prompt the human body to produce a protective immune response that is superior to that elicited by natural infection,' Fauci added. 'This has required a shift in the balance of effort from the empirical development and large-scale testing of candidate vaccines to the discovery of the mysteries of the interaction of HIV and the body's immune system. In the shift of this balance, certain fundamental unanswered questions must be addressed in the discovery process before additional large clinical trials are warranted. Paramount among these knowledge gaps is the need for a better understanding of the events early in HIV infection, beginning at the places where the virus enters the body.'
But Fauci also warned that even should researchers discover a method to boost the immune system's responses to the virus, it's not likely a vaccine alone will offer complete protection against HIV.
'Since it is possible that an HIV vaccine alone will never fully prevent HIV infection the way smallpox or polio vaccines can, our efforts in HIV vaccinology must be part of a broader approach toward HIV prevention that includes the delivery of proven methods, such as HIV testing and counseling, education and behavior modification, the use of condoms, the treatment and prevention of drug and alcohol abuse, syringe-exchange programs, antiretroviral drugs to prevent mother-to-child HIV transmissions, and medically supervised adult male circumcision,' Fauci stated.
