HIV vaccine: How will it work?

Harmony Agere

Extra Reporter

While the prospect of having HIV vaccine clinical trial being done in Zimbabwe for the first time has excited many, the million dollar question has been how the vaccine’s ability to prevent HIV infection will be tested.

Will participants be injected with the virus, to test their immune systems? Will they be “ordered” to engage in risky sexual behaviour? Will one test positive after taking the vaccines? These are just some of the questions that easily come to mind when talk of an HIV vaccine is made. Head of the research team, Dr Lynda Stranix Chibanda, explained that volunteers will not be at risk of being infected with HIV, because the virus will be simulated.

“The virus is not injected but pieces of the viral DNA and protein are given. These pieces cannot cause HIV infection but the body recognises that they come from HIV.

“For the dose or strength of the vaccine – that’s one of the questions to be addressed in our studies.

“The DNA and protein are parts of the virus and are sufficient for the body to recognise which virus they come from and to set off an immune response to attack it.”

According to HIV Vaccine Trials Network (HVTN) one can test positive as result of the vaccines while they are actually not infected with the actual HIV virus.

“Yes, the study vaccines may cause you to test positive on some types of HIV tests. If a participant gets an HIV study vaccine, their body may make antibodies to HIV. Standard HIV tests search for HIV antibodies as a sign of infection.

“Because of this, a person could have a positive HIV test result even if they are not infected with HIV. This is called a vaccine-induced seropositive (VISP) test result.

HVTN says no health problems are associated with a VISP test result but can hamper one’s ambitions to secure insurance or join the military.

“But VISP test results may cause problems in several areas such as medical or dental care, employment, insurance, a visa for traveling, or entry into the military. You might not be allowed to donate blood or other organs. If you are planning to apply for insurance, employment, or the military, one has to inform the study site from the onset. The insurance company, employer, or military agency may not accept HIV test results from the HVTN.

“However, the HVTN can work with them to ensure the right test is done that will show the true HIV status.”