Biotechnology – Australian Science

Hopeful results in latest HIV vaccine trial, but many hurdles to overcome yet

David Borradale — Mon, 23 Sep 2013 00:24:51 +0000

A HIV vaccine, known as SAV001-H has shown promising results in an early clinical trial, with no adverse effects reported and importantly, a significant increase reported in HIV specific antibodies in participants who received the vaccine. In this trial, 33 HIV positive participants were randomly allocated to one of two groups: half into a treatment group receiving the vaccine and half into a placebo group who did not receive the vaccine. The participants were followed up at regular periods, testing safety of the vaccine and antibody response over a one year period. The vaccine has been developed by Dr C. Yong Chan and his team at the University of Western Ontario and has been licensed for commercialisation by the biotechology company Sumagen.

This is welcome news for a disease which killed an estimated 1.7 million people in 2011 (WHO, 2013). Furthermore, there are an estimated 34 million people around the world living with HIV/AIDS, and the disease continues to have a devastating impact in Sub-Saharan Africa where up to a quarter of the population in countries such as Botswana, Lesotho and Swaziland are infected (WHO 2013; UNAIDS 2013). While great strides in treatment of HIV; via the development of antiretroviral (ART) medications, have been made by extending the time it takes for HIV to develop to AIDS, ART treatment is not yet available to all, particularly in the poorest nations; and of course, treatment is much less optimal then prevention of HIV in the first place.

Worldwide adult HIV Prevalence (Click for larger)

The long road to effective HIV vaccines

However development of successful HIV vaccines has proven to be highly elusive, due in part to the rapid mutation rate of HIV, these mutations generating a diverse population of quasi-species of HIV over the length of the infection period – the immune system, itself the target of HIV, is simply not able to keep up (Ackerman and Alter, 2013). This immense genetic diversity of HIV has meant that targeting HIV with effective, universal vaccines has been particularly difficult.

This leads to a cautionary note that must be taken regarding SAV001-H; this was a small, very early trial of this particular HIV vaccine. These early trials are referred to as Phase 1 trials, meaning that its primary focus was on assessing the safety of vaccine, with efficacy or effectiveness assessed only as a secondary objective (see graphic, below). Phase 2 and 3 trials are planned next and it is these trials which are particularly focused on assessing the effectiveness of the vaccine to prevent HIV infection in large numbers of HIV negative participants at high risk of contracting HIV. Furthermore, other promising HIV vaccines have passed through early Phase 1 trials, only to show in later trials no significant efficacy. An example of this was a highly anticipated STEP trial, which was a large Phase 2 trial enrolling 3,000 high risk individuals randomised into a vaccine or placebo group. The vector based vaccine used in this trial failed to show any effect on reducing risk of infection and indeed those receiving the vaccine appeared to be at greater risk of contracting HIV (HTNV, 2013).

Clinical trial phases

Thus some of the early media reports for SAV001-H which have been mentioning ‘eradication’ are very premature and paying scant heed to the long (and sometimes disappointing) road that this vaccine must pass through with its coming Phase 2 and 3 trials, as demonstrated above with the example of the STEP HIV vaccine trial. These promising early results from this latest HIV vaccine trial must be tempered by the historical difficulties in conducting successful HIV vaccine trials.

Cautious optimism

Despite the very real need for caution at this early stage, there are several reasons why many in the health community are particularly optimistic about SAV001-H. This optimism is largely due to the fact that SAV001-H takes a new approach to HIV vaccine design as it uses whole killed HIV viruses. Previous HIV vaccine strategies have used other strategies such as subunit vaccines which basically introduce important proteins (called antigens) to the body to induce a specific immune response, or vector based vaccines to introduce genetic material from the HIV virus via another ‘carrier’ virus; both approaches proving disappointing so far (Sumagen, 2013).

HIV structure: gp120 and gp41 are essential in fusion to immune cells and subsequent invasion

For SAV001-H, the HIV-1 virus is genetically engineered by deleting the activity of specific genes involved in the disease causing process (pathogenicity) and then chemically treated and bombarded with gamma radiation to disable its ability to multiply within human cells (virulence) (Sumagen, 2013). This way, the immune system will still detect and mount a response against the invading virus, but the virus is no longer able to cause disease. The early data from the Phase 1 trial are particularly encouraging as it has been reported that vaccination with SAV001-H produced large increases in two particular antibodies specific for the p24 envelop antigen and gp120 surface antigens of HIV-1 (Western News, 2013).

While gaining plenty of attention, SAV001-H is only one of multiple vaccines in development; a major focus of several other research efforts, are vaccines designed to induce potent antibodies, known as broadly neutralizing antibodies (bNAbs), that are able to potentially block HIV infection (Korber and Gnanakaran, 2011). Promising early research into vaccines that may be able to effectively induce these bNAbs and provide effective immunity against HIV infection have provided another boost to HIV vaccine development efforts. So there is certainly reason to be hopeful about SAV001-H, but we need to mix this hope with a healthy dose of caution at this stage. Also, it is worth noting that any effective HIV vaccines will likely be just one, albeit very important, part in a multitude of preventative strategies, including sex education, male circumcision, microbiocide gels and prophylactic antiretroviral therapies which will result in the effective prevention of HIV infections worldwide.

Sources:

1. World Health Organisation. HIV Data and Statistics [Online]. Available at: http://www.who.int/hiv/data/en/

2. United Nations AIDS (UNAIDS). AIDS Information by country [Online]. Available at: http://www.unaids.org/en/dataanalysis/datatools/aidsinfo/

3. Ackerman M, Alter G. 2013. Mapping the Journey to an HIV Vaccine. NEJM 369(4): 389-391.

4. HIV Vaccine Trials Network (HVTN) [Online]. Available at: http://www.hvtn.org/science/step_buch.html

5. Sumagen. AIDS vaccine [Online]. Available at: http://www.sumagen.co.kr/english/business/aids_vaccine.htm

6. HIV vaccine produces no adverse effects in trials. Western News, September 3, 2013 [Online]. Available at: http://communications.uwo.ca/western_news/stories/2013/September/hiv_vaccine_produces_no_adverse_effects_in_trials.html

7. Korber B, Gnanakaran S. 2011. Converging on an HIV Vaccine. Science 333; 1589-1590.

All images sourced from public domain (Wikimedia)

Cite this article:
Borradale D (2013-09-23 00:24:51). Hopeful results in latest HIV vaccine trial, but many hurdles to overcome yet. Australian Science. Retrieved: May 02, 2024, from http://australianscience.com.au/health/hopeful-results-in-latest-hiv-vaccine-trial-but-many-hurdles-to-overcome-yet-3/

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Free and Open Source Agriculture

Sridhar Gutam — Thu, 21 Jun 2012 01:05:22 +0000

Credit: Thamizhpparithi Maari, Wikimedia Commons

A recent news published online by The Wall Street journal about the Indian Council of Agriculture Research (ICAR) offer of germplasm from its massive seed gene bank at National Bureau of Plant Genetic Resources (NBPGR) to multinational corporations (MNCs) in exchange for expertise and a share of the profits made me to put forth before you about the topic ‘Free and Open Source Agriculture’ which is proposed and discussed by Janet E. Hope (2004), Susan H. Bragdon (2005), Daniel D. Holman (2007) Keith Aoki (2009) and others. It is strange that the ICAR which is an the apex body of the world’s largest National Agricultural Research System (NARS) coordinating, many institutes involved in basic and strategic research, education and extension, is still looking at MNCs for next generation genetic technologies and the for the want of the same, it is going to share/sell its genetic materials. No doubt agriculture in India and elsewhere in the world is facing challenges from the changing climatic conditions, threats from biotic and abiotic factors. India is rich in biodiversity and with the use of agricultural biotechnology, it is now possible to develop new crop varieties that are tolerant to adverse climatic and poor soil conditions, pests, diseases, insects, weeds etc. and build agriculture and food security. The MNCs with their huge investments have taken proprietary rights on most of the rapid scientific and technological advancement tools and products. Now they are looking at harness the public plant genetic resources for the creation of new generation of crops with the use of advanced molecular biology tools.

As per the Convention on Biological Diversity (CBD) 1992, plant varieties are national sovereign resources and with sui generis system of protection in India under the Protection of Plant Varieties & Farmers’ Rights Act, 2001(PVFR P), the plant breeders and farmers have been given rights for conservation, improvement and re-use. Now the question arises once the MNCs takes the role of plant breeders and claim their rights on the improved traditional varieties with the help of biotechnological tools, does the farmers have any right to use the same improved material for his own use? or would they be left with no choice other than to buy the planting material at the cost specified by the MNCs?

As per the PPVFR, the farmers would have the right to claim for rewards from Gene Fund if genes from their local varieties are used for the production of improved material for commercial purpose, they don’t have any right to participate in decision making on matters related to the conservation and sustainable use of plant genetic resources for food and agriculture as suggested in the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGR) in Article 9.2. However it seems that in man of the decisions on sharing/selling the country’s germplasm, there is no seeking of prior consent from the farmers/communities from whose locations, the germplasm might have been collected.

Under the IPR regime, the free progress of science and innovation is hampering and the fruits are not reaching to the public while, the exchange of knowledge and tools should be a way of life in agricultural research. Hence, I would like to put forth the concept of ‘Open Source‘ in Agriculture and Biotechnology which is proposed/discussed since quite sometime when the Free and Open Source Software (FOSS) and GNU movements had become global movements. In contrary to the proprietary software which gives only license to work, FOSS gives source code and a bundle of rights to the user to use, reverse engineer, learn, share and improve it. We are seeing now many FOSS products which are built by the community and are very good. These products are licensed as ‘Copyleft‘ or ‘Share Alike‘ of creative commons and or GNU Public License which requires that the copies or adaptations of the work to be released under the same or similar license as that of original.

This concept of FOSS initiative in agriculture has not taken up as a policy by the public funded research institutes. Though the germplasm is being received and sent (shared) by material transfer agreements (MTAs), many of the breeders are not exploring the concept of ‘Share Alike‘. When the crop improvement is being taken up by both public and private, the MTAs should have the licensing terms which asks the agencies to share their improved materials in the similar terms to the public for further use and development without seeking any royalties for the further improvement and use. Recently, there are reports that there is a charge against the Bt Brinjal’s developers in India for violation of the Biological Diversity Act, 2002 and allegations that they had accessed Indian varieties of brinjal for the development of genetically modified ‘Bt Brinjal’ without prior permission from the National Biodiversity Authority (NBA). These issues could be avoided when the materials are freely available to everyone to use and also for re-use.

Though there is a provision for ‘Compulsory License‘ under PPVFR for undertaking production, distribution, and sale of the seed or other propagating material on the grounds that the reasonable requirements of the public for seeds or other propagating material of the variety have not been satisfied or that the seed or other propagating material of the variety is not available to the public at a reasonable price, there is no provision for the use of the material for further improvement.

The FOSS movement had not built in one day but its a continuous building movement. And if this initiative to happen in agriculture, it would be a great thing. However, for that it needs greater advocacy and to be built by the convinced breeders/farmers. Centre for Sustainable Agriculture from Hyderabad in India which is working for sustainable agriculture is now exploring the concept called ‘Open Source Seeds‘. In the world, the BiOS Initiative of Cambia (BiOS – Biological Innovation for an Open Society) is the one which is based on the GNU/FOSS model and is sharing enabling technologies with large community of innovators under ‘Protected Commons‘. The BiOS licenses when employed for MTAs, would enable the public to access to the technologies freely and there would not be any prevention of the same by appropriation of IPR rights by private players.

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