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Susan Allen

HIV vaccine insight via Rwanda

RwandaRollins

From left: RSPH dean Jim Curran, First Lady Jeannette Kagame, HIV/AIDS researcher Susan Allen, Vice Provost Philip Wainwright

Most of the discussion, when Rwanda’s First Lady Jeannette Kagame recently visited Emory, was not about HIV vaccines, and rightly so. It was about how far Rwanda has come as a country since the 1994 genocide [videos of author Philip Gourevitch discussing Rwanda].

Still, while introducing the First Lady and thanking her for her support of HIV/AIDS research in Rwanda, Susan Allen mentioned a clinical trial for a HIV vaccine that began last year in Rwanda, Kenya and the United Kingdom and is now wrapping up the vaccination phase. Her colleague in Kigali, Etienne Karita, is one of the principal investigators.

The vaccine uses replicating Sendai virus, which causes respiratory tract illness in rodents but not in humans, as a vector to deliver the HIV gag gene. The trial combines this vaccine, administered intranasally, in various configurations with an adenovirus-based vaccine. This is the first time that Sendai virus is being used in a HIV vaccine.

As IAVI Report’s Regina McEnery explains, researchers hope the Sendai vector might recruit targeted immune responses to mucosal tissues and provide an edge to the immune system when it is subsequently challenged by HIV.

In a future post, we plan to provide an additional update on HIV vaccine research, focusing on GeoVax and (separate, for comparison) a planned large-scale followup to the landmark RV144 Thai trial.

Posted on by Quinn Eastman in Immunology 1 Comment

Contraception and HIV risk

Does hormonal contraception increase the risk for a woman to acquire HIV from an infected partner?

This topic, with implications for public health in countries where HIV risk is high, has been contentious. Some previous studies had found the answer to be yes, for methods involving injectable progesterone such as Depo-Provera. This led the World Health Organization in 2012 to advise women using progesterone-only injections to use condoms to prevent HIV infection.

At the recent AIDS 2014 meeting in Australia, Emory epidemiologist Kristin Wall presented data from public health programs in Zambia. This is another study emerging from the Zambia-Emory HIV Research Project directed by Susan Allen.

Wall’s presentation is available here.

Studying 1393 heterosexual couples with a HIV-positive male partner over 17 years, Wall and her colleagues found no significant difference in incidence rate per 100 couple years between hormonal and non-hormonal forms of contraception. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Fighting HIV, biomedical and behavioral hand in hand

In the HIV/AIDS arena, the idea of “treatment as prevention” has been gaining strength. Multiple studies have shown that treatment with anti-retroviral drugs can dramatically reduce the likelihood that someone infected with HIV will be able to pass the virus to someone else.

However, a recent strategy document for HIV/AIDS prevention developed by a International Antiviral Society–USA panel, co-led by Rollins Global Health chair Carlos Del Rio, puts biomedical interventions hand in hand with psychosocial measures such as couples counseling and treatment for drug dependence.

Why? Because people everywhere can have trouble sticking to antiretroviral treatment, even if drugs are available. And couples counseling by itself is valuable.

A powerful example of how this plays out, and of the importance of couples counseling to the effectiveness of antiretroviral drugs in prevention, comes from a recent presentation from Emory epidemiologist Kristin Wall at the AIDS 2014 meeting in Australia. The website NAM Aidsmap had a helpful write-up of her presentation, which is available here. Thanks to co-author Susan Allen for alerting us to this.

CVCT (couples voluntary counseling and treatment) greatly enhanced the preventive effect of antiretroviral treatment, when compared to treatment without counselling, Wall’s analysis of a large cohort of couples in Zambia showed. 

Update: Allen points out that couples counseling by itself was effective in helping people avoid HIV, with a 75 percent reduction in incidence for couples where the HIV+ partner was not receiving antiviral therapy or with HIV negative couples.  Read more

Posted on by Quinn Eastman in Immunology 2 Comments

HIV discordant couples

On Thursday, NPR had a nicely done story on discordant couples (one partner is HIV positive, the other is HIV negative) in Kenya.

It provided a reminder of Susan Allen’s work in Rwanda and Zambia with discordant couples. It also very simply laid out the policy issues connected with treating discordant couples:

Medical workers are http://www.raybani.com/ extremely interested in discordant couples for two reasons. One is that almost half of new infections in Kenya happen in these relationships. It’s one place where HIV is spreading. The second reason is that when couples are open with each other about their HIV status, managing HIV is more successful…

The World Health Organization now recommends that any HIV-positive individual in a discordant relationship be supplied HIV treatment. But discordant couples are still being treated on an ad hoc basis in Kenya, primarily because the funding for the medication just isn’t there.

Allen’s research provided critical data about HIV Ray Ban outlet transmission and prevention methods, and led to the adoption of the WHO guidelines mentioned in the story. She has said that the WHO guidelines were designed to help partners in a stable relationship work together to prevent the uninfected person from getting the virus and that low-tech, inexpensive prevention methods like condoms are just as important as antiretroviral therapy in this effort.

Posted on by Quinn Eastman in Immunology Leave a comment