VRC starts Phase II vaccine trial

The Vaccine Research Center (VRC) and HVTN have also started a Phase II clinical trial with a two-part vaccine including a DNA-based vaccine candidate followed by a boost with an adenovirus serotype 5 vector. This vaccine candidate differs from the ongoing Phase IIb Merck trial (see above) because it uses a different version of the Ad5-based vaccine candidate and also first uses a DNA vaccination to prime the immune system. The VRC has observed an improved response when the DNA vaccine candidate and Ad5 are administered in a prime/boost manner (seeAIDS vaccine researchers find promise).

This study, HVTN 204, seeks to enroll 480 volunteers at sites in North and South America, Africa, and the Caribbean in order to determine the safety and level of immune responses generated by the candidate as compared to an inactive substance known as placebo. Volunteers that are randomly selected to receive the DNA/Ad5 candidate will receive 3 injections of the DNA and a single Ad5 boost over a period of 6 months. Half of the trial participants will be enrolled at HVTN sites in the Americas as well as in Haiti and Jamaica, while the other half will be at sites in South Africa and Botswana.

This vaccine is the first developed at the VRC to move into the second stage of clinical testing. The US-based company Vical is manufacturing the DNA portion of the vaccine and the adenovirus vector was developed by the VRC in collaboration with GenVec. The DNA/Ad5 candidate includes HIV genes from subtype A and C, which are the most prevalent forms of the virus in Africa and parts of Asia. Volunteers can not become HIV infected from this vaccine candidate.

This same candidate will be evaluated further in a series of Phase I and II clinical trials in Africa in cooperation with IAVI and the US Military HIV Research Program, pending regulatory approvals in these countries.

All articles written by Kristen Jill Kresge