To mark World Aids Day 2016, here are five of the biggest research breakthroughs relating to HIV and Aids.

5. Antiretroviral therapies confirmed to be highly effective

A pair of studies from the World Health Organization found that antiretroviral therapies are effective at reducing HIV infections and deaths from Aids.

At the end of 2015 almost half of the estimated 37 million people living with HIV were receiving antiretroviral therapy.

Antiretroviral therapies stop the proliferation of HIV in the body to reduce the viral load. This greatly reduces the risk of transmitting the virus to more people. If both sexual partners are receiving antiretroviral therapy then the likelihood of transmission can be reduced by up to 96 per cent.

It's thought that antiretroviral therapy has saved nearly 8 million lives so far.

4. Antibody treatment proves effective HIV treatment for those who resist antiretroviral therapy

A Phase III clinical trial has found that people who do not respond to antiretroviral therapy can be treated with monoclonal antibodies.

Antiretroviral therapy has several side effects, such as anaemia, nausea and diarrhoea. Some patients do not respond to these therapies at all. Research has shown that monoclonal antibodies could soon be an alternative treatment option for people diagnosed with HIV.

The treatment has yet to be approved by the Food and Drug Administration in the US.

There is still no cure for HIV or Aids jacinta lluch valero / Flickr

3. Antibody therapy could boost immune system to help patients off antiretrovirals

Antibody therapies could also help as an additional treatment to antiretrovirals. Monkeys that had the simian equivalent of HIV – SIV – had their viral load reduced to undetectable levels after receiving the antibody anti-alpha4/beta7 after receiving antiretroviral therapy.

The paper, published in the journal Science, found that after receiving the antibody once a fortnight for 32 weeks, high levels of SIV did not return in the monkeys when antiretroviral therapy was stopped.

A pilot clinical trial of the therapy in humans is now underway.

2. Gene editing technology used for HIV research

The use of precise gene-editing technology in HIV research could hasten the search for a cure for HIV and Aids. Researchers at the University of California San Francisco used CRISPR-Cas9 technology to investigate human immune cells' resistance to HIV.

HIV infected cell
An image portraying an HIV-infected cell AJC1 / Flickr

They found that mutations in two genes – CXCR4 and CCR5 – offered some protection to HIV. This research will now form the basis for further studies into whether this can be converted into an effective treatment.

1. Crucial HIV protein structure seen up close

The protein that allows HIV to recognise and infect human immune cells was identified in high resolution for the first time. In a study published in the journal Science, researchers modelled the protein in its natural form.

This could help medical researchers identify antibodies that could target the protein to stop the virus before it can infiltrate the immune system.