Saturday May 25, 2019

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

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www.pbs.org

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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Uganda Remembers AIDS Victims by Marking ‘International AIDS Candlelight Memorial Day’

According to the Uganda AIDS Commission, the country records 50,000 new infections annually, about one-third of them being young people

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FILE - A campaign supporter lights candles in the Philippines as part of commemorations of International AIDS Candlelight Memorial Day in Quezon city, metro Manila, the Philippines, May 14, 2016. VOA

Uganda is marking International AIDS Candlelight Memorial Day with activities to remember the estimated 2 million Ugandans who have died of the disease.

While the government and development partners have increased campaigns for HIV awareness, however, the stigma and discrimination attached to the disease keep many Ugandans fearful from learning of or talking about their HIV status, says those who carry the virus.

Twenty-five-year-old Namanya Martin Paul was born with HIV. Having lost his father to AIDS at the age of 2, he only learned about his status at age 10 when his mother, also HIV positive, was attending antenatal care. His other three siblings were then found to be HIV-positive. Paul was forced to change schools due to discrimination until he made a decision to open up.

“It’s not easy. There’s a particular point in time where a nurse got to know my situation, where I was keeping my medication and she actually, like, made it very open to school,” Paul said. “So, I called for a school parade and told these people, this is who I am. Am living with HIV, am taking my medication. And, you need to support me.”

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According to the Uganda AIDS Commission, the country records 50,000 new infections annually, about one-third of them being young people. Flickr

The International AIDS Candlelight Memorial Day is one of the world’s oldest and largest grassroots mobilization campaigns for HIV awareness. According to the Uganda AIDS Commission, the country records 50,000 new infections annually, about one-third of them being young people. Sarah Nakku, the U.N. AIDS community mobilization adviser, says many infected people are careful about revealing their status.

“We do have laws that discriminate against people living with HIV. … That instead of allowing people to come out openly,” Nakku said. “Incidentally, people decide to hide because they do not want to fall victims of the law. We also have schools where discrimination does happen. If you don’t tap into the teachers, this young person cannot be supported to adhere on treatment.”

In 2018, the government launched an initiative that demands every institution, both government and private, address the needs of HIV-positive people as part of its workplace policy.

Dr. Nelson Musoba, director-general of the Uganda AIDS Commission, says that even though the government has set up more effective measures to curb the disease, Ugandans need to be more careful about exposing themselves to HIV.

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School girls light candles in the shape of a ribbon during a HIV/AIDS awareness campaign ahead of World Aids Day, in Ahmedabad, India, Nov. 30, 2016. VOA

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“So, we also have the pre-exposure prophylaxis, which the HIV-negative partner takes to ensure that they remain HIV-negative. There’s research going on, on vaccines, on other treatments, but we need to stay alive for us to benefit from those technologies. We can’t afford to be reckless just because there’s treatment,” Musoba said.

The Ministry of Health says Uganda is close to achieving its “90-90-90” target, set in 2014. The aim is for 90 percent of people living with HIV to know their status, 90 percent who test positive to enroll in care and treatment, and 90 percent of those in treatment to achieve “viral load suppression” — that is, for the virus to become inactive. (VOA)