Monday November 19, 2018

Scientists hopeful of ‘full-length single chain’ AIDS vaccine

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NewsGram Staff Writer

Robert Gallo, the scientist who first proved in 1984 that HIV triggered the disease AIDS, is again all set to begin the trial of its vaccine in the US. The vaccine which has been developed over the past 15 years by Gallo is a little different and is expected to bear fruitful results.

The initial phase, involving 60 volunteers, will test the safety and immune responses of the vaccine. This study will reveal whether the vaccine is more effective than the other 100+ AIDS vaccines that have been tested over the last three decades. Extensive testing on monkeys have yielded positive results.

Despite the presence of potential vaccines, the challenge with AIDS is that HIV directly infects white blood cells (RBC) called T-cells, so it literally turns our immune system against us. So, once the virus enters a T-cell, it’s invisible to the immune system.

The sole possibility to combat the threat is to pump in antibodies against the HIV surface proteins. However, doing so is equally difficult owing to the fact that the retrovirus can regularly change its viral envelope to hide particular surface proteins.

But Gallo and his team at the Institute of Human Virology in USA believe that they may have now found a moment when the HIV surface protein, known as gp120, is vulnerable to detection – the moment the virus binds with our bodies’ T-cells.

When HIV infects a patient, it first links to the CD4 receptor on the white blood cell. It then transitions, exposing hidden parts of its viral envelope, which allow it to bind to a second receptor called CCR5. Once HIV is attached to both these T-cell receptors, it can successfully infect the immune cell. at this stage, it is impossible to stop its juggernaut.

Gallo’s “full-length single chain” vaccine contains the HIV surface protein gp120, engineered to link to a few portions of the CD4 receptor. The motive is to fuel antibodies against gp120 when it is already attached to CD4 and is in a vulnerable transitional state. The aim of the whole process is effectively stopping it from attaching to the second CCR5 attachment.

Gallo himself admitted to Jon Cohen over at Science that full-length single chain vaccine is a “terrible name”.

The trial is being run in collaboration with Profectus BioSciences, a biotech spin-off from the Institute of Human Virology, and Gallo explained that extreme thorough testing on monkey and getting the fund to develop a human-grade vaccine have resulted in a delay to get to this point.

“Was anything a lack of courage?” he asked Science. “Sure. We wanted more and more answers before going into people.”

Let’s hope that caution pays off, and we may finally have a viable contender for an AIDS vaccine on our hands.

(With inputs from www.sciencealert.com)

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Nearly 40 Individual HPV Types Linked to HIV Infection

Regarding prevention and treatment, Brown recommends the HPV vaccine, widely provided to everyone regardless of sex, gender, or sexual orientation before sexual debut, and for genital wart treatment

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HIV
Nearly 40 individual HPV types linked to HIV infection. Pixabay

Scientists have for the first time identified 37 individual types of the human papillomavirus, or HPV, that are specifically linked to human immunodeficiency virus (HIV) infection.

The findings showed that a person with any HPV type, more than one HPV type, or high-risk HPV are more likely to test positive for HIV.

“Although most studies have shown a general link between HPV and HIV co-infection, our findings illustrate the strong relationship between individual HPV types and HIV infection,” said lead author Brandon Brown, Associate Professor at the University of California, Riverside.

“Some HPV types are more linked to cancer and others to warts. This further illustrates the potential utility of HPV vaccine for men who have sex with men and trans women, not only for HPV prevention but also possibly for HIV prevention,” Brown added.

Brown explained that previous research has shown that HPV, in general, was linked to HIV infection, but his research team looked at infection with 37 HPV types and found that individual types are linked, “which is more specific than saying HPV is linked”.

The study, published in the journal PLOS ONE, identified HPV types such as HPV16, 18, 31, 33, 35, 52, 58, linked to HIV.

HIV Aids
Computer simulations can also predict the spread of HIV: Study. Flickr

For the study, the team investigated nearly 600 men who have sex with men, or MSM, and transgender women in Lima, Peru.

Brown and his colleagues started with two groups, one with genital warts and one without, and followed participants over two years to see who contracted HIV.

Of the 571 participants who completed at least two study visits, 73 acquired HIV in two years — a 6 per cent HIV incidence rate.

Previous study with female sex workers showed that the HPV vaccine still provided protection to high-risk groups.

Also Read- Anupam Kher Wants History Not to Misjudge Manmohan Singh

Regarding prevention and treatment, Brown recommends the HPV vaccine, widely provided to everyone regardless of sex, gender, or sexual orientation before sexual debut, and for genital wart treatment.

“Even if the vaccine is not provided before sexual debut, there can be strong benefit if given at any time to prevent HPV-associated disease and also HIV,” he said.

“We know that HPV is the most common STI, and we know that HPV vaccine works to prevent chronic HPV infection. What we need now is to implement the vaccine in a better way. The availability in many other developing countries is low at best and absent at worst.” (Bollywood Country)

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