Uganda to conduct another HIV vaccine trial

Makerere University Walter Reed Project (MUWRP) is this July launching another third Phase I trial attempt to develop an HIV vaccine since 1999 when the first trial was launched.

Phase I is the first stage in developing a candidate HIV vaccine and involves a small number of uninfected participants at a low risk of acquiring HIV.

This year’s trial, according to the MUWRP’s Executive Director Dr Hannah Kibuuka, will be multisite, including Thailand and U.S.A –with 120 volunteers, 60 of which are Ugandans.

“In continued effort to develop an HIV vaccine, we have to undertake this trial and others until a safe and effective vaccine is found,” Dr Kibuuka said. 

Dr Hannah Kibuuka

Volunteers have to be free of illnesses such as hypertension, sickle cells and diabetes and undergo intense HIV counseling and follow-up during the trial.

Currently, MUWRP is undertaking a vaccine trial involving 42 volunteers from Uganda to determine the body’s immune response and vaccine safety. Other participants in this trial have been recruited from Kenya, Tanzania and USA.

Dr Fatim Jallow, MUWRP’s deputy laboratory director says the lab is well equipped for the July trial.

On going activity at the MUWRP lab where the trial will be held

Stages of Hiv vaccine trials;

At the early stages of development, Phase I and II trials, scientists test to find out how the body responds to the vaccine. After a person is vaccinated, their blood is sent to the laboratory to identify whether his/ her body has generated a response that can fight HIV.

“The only way to identify if the vaccines actually protect against HIV/Aids is in a large Phase III trial with thousands of volunteers who are at risk of HIV infection,” Dr Francis Kiweewa, head of research and scientific affairs at MUWRP said.

Phase III trials can last three to five years.

Currently the World Health Organization (WHO) and UNAIDS are working to facilitate trials in African countries through the African AIDS Vaccine Programme (AAVP), an initiative adopted in 2001 by African Heads of State at the African Summit on HIV/Aids, Tuberculosis and Malaria in Abuja, Nigeria.

Challenges;

Currently, one of the challenges is developing a single vaccine that will effectively deal with the different HIV subtypes. There are at least nine Hiv subtypes circulating in the world.

Most research to date has focused on a vaccine for Hiv subtype B, which is the main subtype in the Americas, Australia, Japan and Western Europe.

“There is still a challenge for a common vaccine that will prevent Hiv among all the strains especially A, C, D and E common in sub-Saharan Africa and Asia,” Dr Kibuuka said.

Earlier trials in Uganda

In 1999, Uganda launched Africa’s first Hiv vaccine trial, a small Phase I safety study involving 50 volunteers at the Joint Clinical Research Clinic (JCRC). However, this generated massive public criticism with misconceptions that the vaccine would trigger new infections and debate whether volunteers would be compensated in case of harm.

In 2003, Uganda launched its second vaccine trial with support of the International Aids Vaccine Initiative (IAVI). This was also a Phase I study which tested a combination of two vaccines based on the Hiv subtype A. The study enrolled 50 volunteers and ran until February 2005.  

A researcher displays preserved blood samples collected from volunteers at the MUWRP laboratory

Trials worldwide

In 2009, a Phase III trial vaccine RV-144 in Thailand yielded modest results of a 31% efficacy meaning that it reduced the risk of acquiring HIV by 31%.

This is the first study that indicated that it that a vaccine could work.

But in the latest trial failures, researchers in the US according to an article in the Los Angeles Times, ‘HIV vaccine trial shut down’ have stopped a trial after the experimental vaccine failed to both prevent HIV transmission and to reduce viral load in those who contracted the virus.

The article, published on April 25 2013 reports that the trial started in 2009 and enrolled 2,504 men who have sex with men (MSM) and transgendered people who have sex with men in 21 sites in 19 U.S. cities. Of the 1,250 participants who received the experimental vaccine 27 became HIV positive during the study.

HIV/Aids burden in Uganda

According to the 2011 Uganda Aids Indicator Survey (UAIS), about 7.3% (about 1,390,000 Ugandans) of adults aged 15 to 49 are living with Hiv. There is an estimated 20,000 to 25,000 pediatric HIV infections annually and currently new infections are about 145,000 up from 124, 000 in 2009 and 128,000 in 2010.

Treatment options

Current treatment in Uganda involves the use of several antiretroviral drugs, termed Highly Active Antiretroviral Therapy (HAART), which can extend the life expectancy of people living with Hiv and decrease viral load without eradicating the virus.

Other treatment options include safe male circumcision, Option B+ one of the four prongs of the elimination of mother to child transmission (EMTCT), pre and post exposure Prophylaxis.

With giant steps being made in research and development of a vaccine, scientists hope to develop a feasible vaccine to reduce risk of acquiring the virus.