Wednesday July 18, 2018

New HIV vaccine candidate may generate immune response: Study

0
//
104
Republish
Reprint

Washington: An experimental vaccine candidate may have the potential to stimulate the immune system to block HIV infection, according to new research.Symptoms_of_acute_HIV_infection

The findings may represent a leap forward in the effort to develop a vaccine against HIV, which has so far struggled to elicit antibodies that can effectively fight off different strains of the virus, according to three papers published on Thursday in the US journals Cell and Science.

“The results are pretty spectacular,” said Dennis Burton of the Scripps Research Institute (TSRI), who led one of the studies, Xinhua reported.

Currently, many vaccines use a dead or inactive version of the disease-causing microbe itself to trigger antibody production, but immunisations with “native” HIV proteins are ineffective in triggering an effective immune response, due to HIV’s ability to evade detection from the immune system and mutate rapidly into new strains.

This challenge has led many researchers to believe that a successful AIDS vaccine will need to consist of a series of related but slightly different proteins called immunogens (substances that induce a specific immune response) to train the body to produce broadly neutralising antibodies, a special class of immune system molecules that can bind to and neutralise a wide range of globally occurring HIV variants.

In the new studies, the researchers tested one of these potential proteins, an immunogen called eOD-GT8 60mer, which would bind to and activate B cells needed to fight HIV.

vaccine.jpeg.size.xxlarge.letterbox

Using a technique called B cell sorting, the researchers showed that immunisation with eOD-GT8 60mer caused two different mouse models to produce antibody “precursors”, which have some of the traits necessary to recognise and block HIV infection.

This suggested that eOD-GT8 60mer could be a good candidate to serve as the first in a series of immunisations against HIV, the researchers said.

The US National Institutes of Health has funded the research. (IANS)

Click here for reuse options!
Copyright 2015 NewsGram

Next Story

HIV Drug Is Not Linked to Depression: Study

A new study of a popular HIV drug could ease concerns about its link to depression

0
A doctor draws blood from a man to check for HIV/AIDS at a mobile testing unit in Ndeeba, a suburb in Uganda's capital, Kampala.
A doctor draws blood from a man to check for HIV/AIDS at a mobile testing unit in Ndeeba, a suburb in Uganda's capital, Kampala. VOA

A new study of a popular HIV drug could ease concerns about its link to depression. Researchers in Uganda found that efavirenz, once feared to lead to depression and suicide, did not cause the expected negative side effects in their patients.

Efavirenz is an affordable, once-a-day pill used around the globe to treat and prevent HIV/AIDS. It’s “the treatment of choice” in most of the world, according to Africa Health Research Institute’s Mark Siedner, “especially [in] countries that depend on global aid to treat HIV.”

But some fear that efavirenz may come with a cost.

Some studies in the United States and Europe found the drug increased patients’ risk of depression or suicide, although other studies did not.

The mixed results prompted many doctors in the United States to prescribe more expensive but potentially safer drugs.

Siedner wanted to take another look at the risk of depression, this time in an African population. From 2005 until 2015, he and a team of Ugandan and U.S. doctors tracked 694 patients who took either efavirenz or another antiretroviral medication. They regularly asked the patients whether they experienced depression or suicidal thoughts.

No difference

Their analysis, published in the Annals of Internal Medicine, showed there was no difference between the two treatments. Siedner told VOA, “In other words, efavirenz was not associated with a risk of depression. If anything, there seems to be a signal that potentially it was associated with a decreased risk. But it wasn’t a strong enough [signal] for us to say that.”

The authors also reported that of the 17 participants who died in the course of the study, not a single death was a suicide.

Siedner has two possible explanations for why their findings differed from those in Western countries. “One potential cause is that every single ethnic group in the world, of course, is different, and different in many different ways — different socially, different environmentally, and in this case they may be different genetically.” His team is looking at whether the genes that control metabolism of the drug have a role to play in this story.

HIV Aids is a deadly disease.
HIV virus is Not Linked To Depression. Flickr

A second explanation could be the effectiveness of the drug. Because efavirenz is so potent, it could be keeping people healthier than they expected, so patients are less likely to report negative emotions.

The study is important, said Anthony Fauci, who heads the National Institute of Allergy and Infectious Diseases, because it pushes back against “the initial observation of suicidal ideation and suicide and depression” as caused by efavirenz. He told VOA, “I think now what you’re seeing is that with these conflicting reports, it’s likely someone will come in [with] the proposal to do a randomized study and take a look. So the story isn’t ended with this paper.”

As more research on the safety of efavirenz is conducted, new and cheaper drugs that might replace it are on the horizon. One of them, dolutegravir, might also pose a risk, however. A study in Botswana found dolutegravir was linked to neural tube defects in embryos, meaning it might not be safe for pregnant women. As always, further research is needed to confirm whether this is a common problem or specific to the population studied in Botswana.

Also read: UNAIDS : World Is At A “Defining Moment” In A Battle Against HIV/AIDS

“I think the whole field right now is in a bit of a holding pattern,” Siedner said when asked about dolutegravir and the future of HIV medication. (VOA)