Published: Mon, July 09, 2018
Medicine | By Douglas Stevenson

A new HIV vaccine shows positive results in human trails

A new HIV vaccine shows positive results in human trails

"Although these data are promising, we need to remain cautious", said study leader Dan Barouch, a Harvard Medical School professor. To date, the "mosaic" is one among the only five experimental HIV vaccines that have proceeded to efficacy human trials.

While there have been HIV vaccines that have been approved for human trials in the past, only one was shown to provide protection against the disease, and it's rate of protection was considered too low to be implemented more widely.

Other researchers caution seeing this vaccine as the final solution to the virus.

In the APPROACH trial of almost 400 participants, researchers conducted a multicenter, randomized, double-blind, placebo-controlled study to assess the safety, tolerability, and immunogenicity of several vaccine regimens in humans.

The team created a mosaic-style vaccine by taking parts from different HIV viruses and combining them.

HIV-1 is the most common form of the virus, while HIV-2 is relatively uncommon and less infectious.

Researchers, including those from Harvard Medical School in the USA, found that the "mosaic" vaccine, created by combining pieces of different HIV viruses, is well-tolerated and generated comparable and robust immune responses against HIV in healthy adults and rhesus monkeys.

Currently, there are no licensed prophylactic HIV-1 vaccines available, which the study authors reported as being potential related to the lack of direct compatibility between the preclinical studies and clinical trials.

According to UNAIDS, the United Nations program on HIV and AIDS, an estimated 1.8 million people around the world become infected with the virus every year, with about 5,000 new cases every day.

In a randomised, double-blind, placebo-controlled trial, scientists tested various combinations of the mosaic vaccine in people aged 18 to 50 who did not have HIV and were healthy.

Most attempts have failed because the virus is able to rapidly mutate, making most vaccines ineffective. They were injected with the vaccine four times in the span on 48 hours.

The researchers also noted several limitations, including the fact that that the relevance of vaccine protection in rhesus monkeys to clinical efficacy in humans remains unclear.

"I can not emphasise how badly we need to have a get rid of HIV in the next generation altogether", said Francois Venter of the University of the Witwatersrand Reproductive Health and HIV Institute in South Africa.

Study participants in the APPROACH trial were taken from 12 clinics located in east Africa, South Africa, Thailand and the USA. All of the vaccine combinations turned out safe and produced an anti-HIV immunity.

Buchbinder said that she hoped "to validate our non-human primate model to see if it works for humans and if we see the same correlates of protection".

Scientists also carried out a parallel study where they gave monkeys the vaccine to protect them from getting simian-human immunodeficiency virus - a virus similar to HIV that infects monkeys.

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