New insights from AIDS vaccine conference

By Hilary Bainemigisha and John Agaba in Barcelona

The AIDS Vaccine conference 2013 was on Thursday concluded in Barcelona with optimism among researchers and funders about the way science is going.

“We are in pretty much better situation ever as regards what we now know about HIV, our immune system and how we can enhance the body’s defenses to prepare and stop the virus from destroying it,” says Bill Show, the director of Global HIV vaccine Enterprise and one of the main organizers.

The conference brought together researchers, donors, expert implementers and other stakeholders to discuss developments in the search for another effective tool that can stop HIV spread. This year over 1,000 people attended the three day event.

“The future of vaccine research is much brighter,” said Mitchell Warren of AVAC, a global advocacy for HIV prevention, “I can’t say we are a decade away but we are in a good position to move faster.”

The optimistic developments at the conference include the following.

Progress on candidate vaccines
The conference heard that vaccines being designed and studied today are much more high tech that the traditional ones of a few years back.  According to Dr Galit Alter, a researcher from Cambridge, US, modern vaccines are designed with the help of computer models to deliver better, smarter and more efficient body responses.

“Every vaccine research that had been done has yielded lots of valuable information on which we build newer vaccines. We now have better methods of teaching our immune system to respond in all areas. We have learnt more about the virus, the immune system, the role, duty and procedure of each component and we can safely say that the next 10 years will be very exciting in vaccine research,” she said.

So far clinical trials are taking place in 17 countries which include Uganda, Kenya, Rwanda, Mozambique and South Africa and Tanzania. Others are; Brazil, China, Peru, Thailand and US. In Europe there is France, Italy, UK, Spain and Germany.

The number of vaccine volunteers so far is 34,522. The capacity to conduct high quality clinical research has spread from the US and Europe to Africa, Asia and Latin America. The funding, so far, has totaled to $8b.

There is a new trial, the Pox-Protein Public Private Partnership (P5), which is building on the success of the RV144 trial carried out in Thailand in 2009. This Thailand trial provided the first evidence in humans that a safe and effective preventive HIV vaccine is possible.

Although efficacy was 31.2% at the end of the study, there was higher early effect (60%) at 12 months. Subsequent trials elsewhere did not show any effect.

Mitchel said the P5 is a diverse group of organizations which came together and decided to build on the success of the RV144 HIV vaccine trial. They are planning trials of an improved version in southern Africa and Thailand.
 
Therapeutic vaccine
Galit said the other exciting development in the vaccine world is the therapeutic approach. Many scientists have focused on the study of a vaccine that can help the body get rid of the virus after the infection has taken place.

“The Germany cure of HIV using the bone marrow transplant opened the hope for research in this direction. We are looking into making a vaccine that will intervene at an early stage of infection to teach the immune system how to figure out a response. Usually at this stage, the virus replicates a lot in the person till his immunity manages to suppress it. After helping the suppression with ARVs, we can introduce a vaccine on how to fight on so that whenever the virus comes out of its hiding place, it is killed.”

 Passive immunity
Scientists are now in advanced technology that can engineer immune cells which can induce neutralising antibodies against HIV. These unbelievable molecules can be functionalized into killers of HIV and introduced into the body of an infected person.

 Use of an adenovirus
An adenovirus is a common flu and sore throat virus that lives in humans without adverse effect. A defective adenovirus cannot grow or cause infections in humans. Scientist announced that it can be altered to become useful as a vector that transports the vaccine candidate into the human body. The success of a vaccine is in convincing the body’s immune system that the body is under attack so the body can mobilized to defend itself. The vessel that delivers the vaccine matters.

The conference discussed how to harmonize the process of starting a vaccine trial in humans. Taking a candidate vaccine into a Phase I study among humans is a complex multi-step process. Experts on regulatory, manufacturing and product development agreed on how the transition can be done smoothly.

This will be the last conference that handles HIV vaccine. Starting with next year, the vaccine meeting will be merged with the other international HIV conference as a strategy to develop synergies between vaccines, microbicides, and ARV-based prevention. The next conference for HIV research for prevention will take place in 2014 in Cape Town, South Africa.