HIV vaccine trials for Zimbabwe


Zimbabwe has partnered with the US-based HIV Vaccine Trials Network (HVTN) for a HIV vaccine trial in a fresh effort to find a cure for the deadly disease.

The country is in the middle of preparations to host the 18th International Conference on AIDS and Sexually Transmitted Infections in Africa (ICASA) which will be held from 29 November to 4 December this year. ICASA presents a huge opportunity for Zimbabwe, Africa and the rest of the world to renew global commitment by drawing the world’s attention to how the new Sustainable Development Goals can provide solutions to new and more pressing issues on AIDS and STIs in Africa.

Professor Ann Duerr, Director of Scientific Affairs for HVTN at the Fred Hutchinson Cancer Research Centre in Seattle, said on the sidelines of a public lecture at the University of Zimbabwe (UZ) College of Health Science this week that Harare will be a site for clinical trials.

‘Phase one trials, which are scheduled to start in late 2015 and early 2016 in North and South America and in sub-Saharan Africa will also include Zimbabwe,’ she said.

‘Harare will be a site in that trial and our investigators here will include Dr. Mike Chirenje and Dr. Nyaradzo Mugodi as a co-chair. They are both from the UZ College of Health Science.’

Dr. Chirenje is a professor of obstetrics and gynaecology at the UZ College of Health Science while Dr. Mugodi is a researcher at the same institution.

The studies are funded by the US National Institute of Health and are targeting about 1500 volunteers from sub-Saharan Africa.

Researchers from both institutions will recruit adult volunteers from around Zimbabwe for the trial code named HVTN 703 and HPTN 087.

Scientists say an AIDS vaccine is urgently needed to control the spread of the disease. It is estimated that 33 million people in the world are living with HIV, and 7000 people are newly infected with the virus every day.

Currently, there are over 20 vaccine trials ongoing worldwide with several more trials scheduled to start separately in various parts of the continent.

The World Health Organization report on HIV indicates that sub-Saharan Africa alone accounted for an estimated 69% of all people living with HIV and 70% of all Aids deaths worldwide in 2011.

Prof Duerr said it has taken over 32 years for scientists to come up with HIV vaccine candidate because the virus constantly develops different strains.

‘It took scientists close to 47 years for them to develop an effective polio vaccine, 23 years for Hepatitis A vaccine, 16 years for Hepatitis B and a vaccine for influenza 98 years,’ she said.

‘Lack of a vaccine has been a major roadblock to the development of an HIV vaccine. People should maintain an optimistic outlook on the future of HIV eradication by a vaccine because there is now strong scientific data to support that position. The aim is to develop a safe and effective vaccine for the prevention of HIV, the virus that causes AIDS.’

It is estimated that the search for a HIV vaccine has so far gobbled more than $8 billion in the past decade.

The path to create a vaccine has been set with challenges, including a 2007 trial of a vaccine produced by Merck, which appeared to make recipients increasingly susceptible to the virus.

Two years later, there was news of a successful clinical trial in Thailand called RV144, which was sponsored by the Surgeon General of the United States Army and was found to reduce HIV infections by 31%.

‘Vaccine trial using a vaccine that has previously shown to offer partial protection against HIV acquisition in Thailand is the one which we will be conducting clinical trials here,’ Prof Duerr said. ‘That vaccine has now been modified to be specific for a sub type of HIV found in sub-Saharan Africa. That vaccine is crudely in trial in South Africa.’

Prof Ann Duerr has extensive experience in the design and conduct of observational studies and HIV prevention trials, most of which were conducted in resource-poor settings in Africa, Asia and South America.

She has published widely on biological and epidemiological determinants of HIV transmission and HIV-STD interactions.

The clinical trial in Harare will use a candidate AIDS vaccine designed to prevent HIV/AIDS caused by multiple subtypes of HIV.

This study marks an important step in the worldwide battle to stop the spread of the HIV/AIDS pandemic.

Zimbabwean scientists have had long-term experience with HIV vaccine trial research and they continue to be at the forefront of promising new vaccine candidates.

The Harare study is a small-scale trial, with a primary aim to evaluate the safety of the product.

Researchers acknowledge the importance of gathering preliminary data on the ability of the candidate vaccine to stimulate immune responses against HIV/AIDS in Zimbabwean volunteers.

Antibodies are protein molecules produced by body cells to fight or neutralise foreign particles such as bacteria and viruses in the body.

Prof Duerr said researchers were still analysing the use of infusion of neutralising antibodies instead of injection vaccine.

Scientists have discovered a key change in the outer coating of the HIV virus, which allowed them to develop antibodies that could fight a large variety of HIV strains.

‘These anti-bodies have shown efficacy to block infection with different HIV subtypes,’ Prof Duerr said.

‘This approach is still being pursued and further studies are required to inform us how antibodies neutralise some subtypes of HIV.’

The SADC region accounts for 34% of HIV infections, according to a 2010 UNAids global report.

Health officials and leaders in the region are collaborating in various programmes to fight the pandemic.

Written by Sifelani Tsiko. This story was sourced from The Southern Times website.


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