When the trial that came to be known as HVTN 505 began in 2009, it had a single endpoint: a decrease in the set point viral load in volunteers who became HIV infected despite vaccination (see Vaccine Briefs, IAVI Report, July-Aug. 2009). Adding protection against infection as an additional endpoint in 2011 resulted in a significant change in enrollment in the HVTN 505 trial. The trial was originally designed to enroll 1,350 circumcised, HIV-uninfected men who have sex with men (MSM) or transgendered women who have sex with men with no pre-existing immunity to adenovirus serotype 5 (Ad5). That is the commonly circulating strain of the cold virus that was used as to construct the vector bearing one of the two vaccine candidates.

It’s probably a bit of an understatement to say vaccine researchers were disappointed yesterday, when they heard about the discontinuation of HVTN 505, a clinical trial that tested the efficacy of a DNA/Ad5 prime-boost vaccine regimen in about 2,500 people. When the trial was stopped, there was no significant difference in HIV infections between those who received the candidate vaccines and the placebo recipients. Beyond that, there was a—statistically insignificant—trend towards more infections among the vaccinated (see previous blog postby Regina McEnery). 

As the country grapples with US$85 billion in across-the-board spending cuts, set in motion after a US Congressional committee failed to pass bipartisan federal budget legislation, it is worth remembering how legislators from both sides of the aisle just a decade ago launched one of the largest US humanitarian efforts since the Marshall Plan. 

Most sexually transmitted HIV infections are the result of just one transmitted virus, but researchers are still wondering what, if anything, makes such transmitted founder viruses so special. Now, a team led by Beatrice Hahn at the University of Pennsylvania has found that transmitted founder viruses have biological properties that give them an advantage when initiating a new infection (Proc. Natl. Acad. Sci. 2013, doi: 10.1073/pnas.1304288110). The results hold true for subtype B and C viruses, both of which were included in the study. 

Our latest issue covers the recent Conference on Retroviruses and Opportunistic Infections (CROI), including news about a functionally cured 30-month-old child, and many antibody-related findings reported at the recent Keystone symposium on HIV vaccines. The topics covered in our news section include a rally against looming cuts to federal funding for health research, and new research that suggests that neutralizing antibodies to the HIV protein Tat could be involved in protection. Enjoy, and let us know what you think!