For most of us, HIV is just about the last thing that comes to mind when the topic of email spam comes up. For Microsoft researchers, however, there's a link between the way spammers change their tactics to avoid filters and the constant mutation of the HIV virus.

Microsoft's TechNet reports that Microsoft Research has teamed up with researchers at the Ragon Institute and research centers in South Africa to quantify how the immune system attacks parts of the HIV virus using a Microsoft-developed tool called PhyloD.

Microsoft blogger Steve Clayton says that the software contains an algorithm and other tools that allow researchers searching for an HIV vaccine to analyze vast quantities of data. Teams in South Africa send new data from HIV-infected individuals to Microsoft Research, which analyzes it and identifies relationships that help researchers understand how different individual immune systems respond to the mutations of the virus.

The researchers hope that the data analysis will help them develop an HIV vaccine.

Clayton says the software, developed by David Heckerman and Jonathan Carlson, builds on Heckerman's previous work to build an email spam filter.

"The same principles that are being used to fight spam in Hotmail, Outlook and Exchange are being used to tackle HIV," he writes. "It turns out there are a lot of similarities between the way spammers evolve their approaches to avoid filters and the way that the HIV virus is constantly mutating."