When it comes to the development of an HIV vaccine, 2009 was a banner year. For the first time, a clinical trial of an HIV vaccine actually showed some positive results. Still, many people remain unconvinced that an AIDS vaccine is even possible.
The Story Starts Here - HIV Vaccine Development - The First 20 Years
2004
The first efficacy test of a T-cell only vaccine is started. This type of vaccine was developed after studies in monkeys found that stimulating a certain type of cellular immunity involving cytotoxic t-lymphocytes didn't necessarily prevent infection, but could keep animals who were infected with HIV from developing clinical AIDS.
Merck starts testing its gag/pol/nef vaccine.
In the journal Science, two groups of renowned scientists debate the ethics of an ongoing HIV vaccine trial in Thailand.
Chiron begins testing an HIV vaccine candidate designed to stimulate both an antibody response and a T cell response.
The first German and Canadian (therapeutic) HIV vaccine trials are launched.
ABL begins clinical trials of a polyvalent vaccine.
Phase I trials of the DNA-MVA vaccine begin in Sweden and Tanzania
AVANT Immunotherapeutics begins testing a vaccine based on the gag p24 protein that is primarily aimed at producing a strong CD-8 T cell response
2005
Eighty clinical trials of more than 50 candidate HIV vaccines have taken place at the time of the Third Forum of the African AIDS Vaccine Programme. Two phase III efficacy trials have failed.
During this year, there were 13 new HIV vaccine trials in 9 countries as well as numerous ongoing HIV vaccine trials. Overall 2005 will see:
- One phase III trial: prime-boost AIDSVAX trial in Thailand.
- Four phase II trials: Merck's Gag/Pol/Nef vaccine, the Targeted Genetics tgAAC09 vaccine, a Vical/GenBec muticlade vaccine, and the Aventis LIPO-5 vaccine.
- Twenty-three phase I trials
2006
The first HIV vaccine trial begins in Jamaica.
GeoVax phase I trial begins in Atlanta.
The trial of an AIDS vaccine designed to help prevent mother to child HIV transmission during breastfeeding begins in Uganda.
2007
Ongoing trials of the Merck Adenovirus 5 Gag/Pol/Nef vaccine are suspended.
Suspension of the Merck trial leads to the postponement of several studies of related vaccines that were slated to begin within the year.
India stops its trials of the Targeted Genetics vaccine after phase I trials fail to induce a sufficient immune response.
Orchestra Therapeutics abandons its HIV vaccine development program.
South African phase II trials of two HIV vaccines, one preventative and one therapeutic, made by FIT biotech show early positive results.
Scientists publish a review of the science of "Elite Controllers" - HIV infected individuals who manage to maintain their viral loads at levels below the threshold of detection for years at a time. At the time of publication, some long term non-progressers had maintained undetectable viral loads for more than 25 years (without treatment). This shows that, at least in a small number of people, the immune system can prevent the progression of an HIV infection to AIDS.
Positive results in several studies of Circumcision and HIV prompt the World Health Organization to recommend circumcision as a way to reduce HIV rates in countries plagued by the AIDS epidemic.
Not long after, scientists find that circumcision is only effective at reducing the risk of HIV transmission to heterosexual men, but did not reduce the risk of transmission in protecting men who have sex with men (MSM).
2008
After 25 years of research and 25 million deaths from AIDS, the scientific community is still reeling from the greatest disappointment yet. Further analysis shows that not only did the highly promising Merck/NIH candidate AIDS vaccine fail, it appears to actually increase susceptibility to HIV in individuals who had pre-existing antibodies against the adenovirus that was used to deliver the vaccine. More people are wondering if it is worth continuing to do HIV vaccine research.
A meeting is called at NIH to discuss the rationale behind ongoing vaccine development efforts.
NIAID cancels the Partnership for AIDS Vaccine Evaluation (PAVE 100) until there are more details on how it would work. This emphasis on better understanding of the mechanics of how individual vaccines encourage immunity to HIV is a result of the recent discussions at NIH.
David Baltimore, a well-respected HIV researcher, tells the American Association for the Advancement of Science that no progress on a vaccine has been made since the discovery of HIV.
GeoVax moves into phase II trials
Merck starts trials of a new vaccine.
The University of Pennsylvania starts recruiting for the PENNVAX-B study - a vaccine based on synthetic HIV DNA.
For the first time, HIV vaccine development proceeds in the reverse direction, from the developing world to the developed, when a vaccine candidate developed in South Africa is scheduled for testing in the United States.
The HIV Vaccine Trials Network, alone, has 15 vaccine candidates undergoing various stages of clinical trials.
2009
2009 is a banner year in the development of an HIV vaccine. In September, scientists who were studying a novel HIV vaccine in Thailand announce the first positive results of an AIDS vaccine trial in humans. Although the study shows only a very small reduction in HIV infection rate, this Thailand HIV vaccine trial re-energizes vaccine proponents.
Scientists identify two possible new antibody targets for future vaccine development after further study of "elite controllers." The two antibodies are to highly conserved areas of the gp120 protein and seem to bind to up to 75% of HIV strains.
Scientists report that some people in long-term sero-discordant relationships, where one person has HIV and the other does not, can develop a salivary antibody response to HIV that may protect them during oral sex.
A study finds that circumcision may be effective at helping to protect heterosexual men from HIV, but it doesn't help their female partners.
