Tag Archives: Infection

The quest for a HIV vaccine

Credit: UNAIDS

There is broad scientific consensus that getting to zero new HIV infections will require an HIV vaccine. Modelling shows that even a partially effective HIV vaccine can save many lives and dollars over time.

Although a vaccine to prevent HIV could be the tool to quicken the pace to reach the end of AIDS, the quest for an effective vaccine has until now proved elusive. The very nature and variety of the human immunodeficiency virus has meant that it has resisted most attempts to quell its spread and scientists and vaccinologists the world over are focusing efforts on finding solutions.

Exciting recent developments in HIV vaccine research are instilling hope around finding an effective vaccine. In 2009, results from a trial in Thailand—RV144—showed a 31.2% vaccine efficacy in preventing HIV infections. Although only modestly protective, the results instilled new hope that an HIV vaccine could be found and made available for populations around the world most in need of a vaccine.

The results represented a significant scientific advance, and were the first demonstration that a vaccine can prevent HIV infection in a general adult population. It was a discovery of great importance and has been followed by more encouraging data in the last couple of years.

Data presented in the past year has been presented on the protective immune responses that were stimulated by the Thai vaccine trial.  Trials are now planned to see if an RV144-like regimen will protect against a strain of HIV infection found in South Africa and against HIV acquisition by people at higher risk of exposure, specifically men who have sex with men.

UNAIDS and the US Centers for Disease Control worked closely with modelling teams to estimate the impact of the RV144 regimen in different countries and with different populations and found that 10% of infections could be prevented if the same 31% efficacy was found in people who receive the vaccine. This shows that a modestly effective HIV vaccine could add to the prevention toolbox of partially effective methods, hastening the decline of the HIV epidemic.

These and other advances in HIV vaccine development—including the design of new tools and technologies for vaccine delivery—have boosted optimism in the field about the prospects for the development of a safe and effective AIDS vaccine.

However, early data from the HIV Vaccines and Microbicides Resource Tracking Working Group is showing that a downturn in HIV vaccine funding that began in 2008 continued through 2011. The quest for effective HIV vaccines is a long-term investment in both the product (vaccines) and in the people who will develop, produce, market and support them. Investments in research and trials are essential and can bring benefits far beyond the AIDS field.

The need for a vaccine to prevent HIV is clear.  There are in excess of 34 million people living with HIV, and every day more than 7000 people are becoming newly infected with the virus. Although a vaccine may not provide the magic bullet to end the AIDS epidemic, it would provide an additional tool to add to the robust package of HIV prevention options which are now available.

UNAIDS will continue to work with multiple partners––scientific communities, national and international AIDS research agencies, the pharmaceutical industry, private foundations, member states, and affected communities––to push the HIV vaccine agenda forward and ensure that the quest for a safe and effective HIV vaccine continues.

Original Article via UNAids

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How Does Criminalisation Affect The Lives Of HIV Positive People?

Yesterday, we posted an article about RITA, which is a test to assess whether someone diagnosed with HIV has been recently infected.  Currently, individuals who are diagnosed as HIV positive are also being told of their RITA (Recent Infection Testing Algorithm) test result and these results can potentially be misused in criminal proceedings.  Read it here.

While most HIV positive people practice very safe sex, and would never have cause to be taken to court, many say that the issue of criminalisation still affects them. A recent survey by researchers from the Sigma research team at Portsmouth University, found that 90% of the HIV positive people they interviewed were critical of the growing trend for criminalisation of reckless HIV transmission. Most said this was because they believed that the responsibility for protected sex should be shared, or because they thought criminalisation increased the stigma they faced. A number also said they believed that criminalisation was a step back towards the culture of ‘blame’ that surrounded the early years of the epidemic.

Criminalisation means there is now an extra concern for any HIV positive person who decides to have a sexual relationship.  LASS, along with many other HIV organisations are finding that we have to take the issue into consideration when giving out advice.

For the vast majority of people living with HIV, preventing others from becoming infected with the virus is a primary concern. HIV positive individuals are, after all, only too aware of just how difficult it can be to live with the illness, and few would wish it on anybody else.

Unfortunately deciding if someone has intentionally, recklessly or accidentally transmitted HIV is not a simple process.  The divisions between each of the three categories can be very blurred, and depend largely on individual interpretation. Even after a decision has been made on what grounds to prosecute, a court may still have a hard time deciding whether to find someone guilty or not

It might appear that proof is a straightforward issue, but proving that an individual has transmitted HIV can be exceedingly difficult.

Firstly it needs to be proven that the accused (let’s call them A) was definitely the source of the accuser’s (B) HIV. This would involve a range of evidence including sexual history, testing history and scientific evidence in the form of phylogenetics. This compares the DNA of the virus that A and B are infected with. If they are completely different then it means B almost certainly did not acquire HIV from A, and the case would probably be thrown out. If the strains are very similar, however, it is possible, though not conclusive, that A infected B. Phylogenetics cannot reliably estimate the direction of transmission and therefore it is possible that B infected A. Furthermore, both could have been infected by the same third party, or different third parties who shared similar strains of HIV. Due to its shortcomings, advocates recommend phylogenetic evidence should only be considered in the context of all other evidence.

The different ways two people, 'A' and 'B', could be infected with similar HIV strains.

For more information on the subject, please visit Avert or The National AIDS Trust

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