Infectious Disease

Tuberculosis (TB) is a major health problem, especially in developing countries. Dr. Kaufmann is leading an international consortium that is studying differences in immune system responses between people exposed to TB who never become sick and those who develop the disease, focusing particular attention on people infected with both HIV and TB in endemic African countries.

Attenuated vaccines, composed of weakened organisms incapable of causing disease, provide prolonged exposure to antigens and have proven effective against several viral or bacterial diseases. Dr. Kappe's team is attempting to extend this concept to a malaria vaccine. In the case of malaria, disease develops when the malaria sporozoite – the form of the parasite that is transmitted from mosquitoes to humans – enters the bloodstream and moves to the liver. There, it grows and divides into thousands of parasites that invade and destroy red blood cells, causing disease. Dr.

Dr. Shattock and collaborators in the U.K. and South Africa will attempt to develop an HIV vaccine that stimulates immunity to the virus in the lining of the vagina. The investigators hypothesize that an HIV vaccine will be most effective at the site where the virus enters the body. Innovative combinations of vaccine antigen formulas and delivery technologies will be used to develop a potentially potent and effective vaccine. The vaccine will be designed to be delivered via low-cost vaginal gels or via silicone rings that fit inside the vagina and can be self-administered.

Dr. Steinman's team is developing vaccines that stimulate the immune system's dendritic cells, which are known to play an important role in stimulating protection against infectious diseases. One approach is to engineer vaccine antigens into monoclonal antibodies against receptors on the surface of dendritic cells. A secondary approach involves engineering genes for the antigens of interest into the yellow fever virus. The project will focus on creating experimental vaccines for a range of diseases, including HIV and malaria.

Dr. Hill and his colleagues are exploring a novel approach to enhancing the ability of plasmid DNA, pox, or adenoviral vectored vaccines to stimulate strong immune responses. Building on recent advances in understanding of pattern recognition molecules as well as intracellular signaling pathways, investigators are working to add intracellular adjuvants (molecular signals that have the potential to enhance immunogenicity) to the vaccine vectors. Also being explored is the effect of adding molecules designed to inhibit regulatory pathways that may be limiting protective immune response.

Vaccines are urgently needed to slow the spread of HIV and hepatitis C virus (HCV), which together infect an estimated 240 million people, most of them in developing countries. To prepare a human vaccine, investigators need an animal model that can help them screen and prioritize vaccine candidates. Dr. Deng and his colleagues are working to improve techniques for creating mouse models with immune systems and livers that are similar enough to humans to allow testing of potential HIV and HCV vaccines.

Hepatitis C virus (HCV) is a major cause of liver diseases, including cirrhosis and liver cancer. Treatment for chronic hepatitis C is often out of financial reach for people in developing countries, and there is no vaccine against the virus. To prepare a human vaccine, investigators need an animal model that can help them screen and prioritize vaccine candidates. Dr. Balling's team, partnering with Dr. Di Santo's group at the Institut Pasteur in France, is working toward the development of mice with livers and immune systems that are similar to those of humans.

To develop new vaccines against some of the world's biggest killers, including HIV, malaria, and tuberculosis, scientists must be able to evaluate promising candidates. Some of the most promising potential vaccines, are made from weakened live versions of the infectious agent. As a result, they cannot be studied in human trials unless researchers can be confident that the weakened vaccines will be safe. Dr.

Most vaccines are delivered by injection, which increases the risk that HIV, hepatitis, and other serious diseases may be transmitted by syringes and needles that are not sterile. Dr. Alonso's team is working to develop a new generation of delivery systems that can easily and effectively carry hepatitis B vaccine through the mucosal lining of the nose. In addition, the team is evaluating whether these delivery systems and the vaccine they carry can be freeze-dried into an inhaled powder that could be stored without refrigeration.

Vaccine delivery systems that target specific areas of the body have the potential to be especially effective against some types of infection. For example, inhaled vaccines may better guard against respiratory diseases, such as tuberculosis, and those that commonly infect the tissues of the nose and throat, such as diphtheria. Dr. Edwards is leading a multidisciplinary team using materials science technologies combined with infectious disease, device, and toxicology expertise to reformulate tuberculosis and diphtheria vaccines into aerosol sprays that can be inhaled.