Viruses

Dengue viruses are a group of flaviviruses that infect humans following mosquito bites in endemic areas. The viruses cause a spectrum of diseases, from mild flu-like symptoms to life-threatening hemorrhagic fever syndrome. There are four serotypes of the virus, and many genotypes within each serotype. The strain diversity causes problems because prior infection with the virus of one serotype can induce an immune response that later enhances the severity of disease following infection with virus of a different serotype. Rare human antibodies neutralize the virus, without enhancing disease.

Human Metapneumovirus (HMPV) is a Paramyxovirus that was discovered in 2001. Despite the fact that it was identified only relatively recently, HMPV is one of the major viral respiratory pathogens of humans. In some studies, it is the second most common virus causing lower respiratory tract illness in children. There are no specific therapies or vaccines for HMPV. 

Noroviruses are the predominant causes for acute non-bacterial gastroenteritis in adults, responsible for about 21 million cases including about 800 deaths in the United States alone. The virus is highly infectious and is easily transmitted through fomites. The disease course is usually mild and self-limiting leading to full recovery, but evokes only a limited immunity. Currently there are no animal models for growing and studying these viruses. All these features - easy transmissibility, high infectivity, low virulence, and constant evolution of the coat proteins - makes this a challenging virus to study and develop vaccines for protection. To better understand the mechanism of infection and identify the residues critical for attachment and entry, we are developing a panel of monoclonal antibodies using PBMC from human subjects challenged with the virus. 

Poxviruses comprise a large group of viruses that infect many species. Smallpox (variola) virus was a major human scourge that was eradicated by a remarkable worldwide vaccination campaign with a live attenuated poxvirus strain (vaccinia virus). Routine universal vaccinia immunization was stopped after variola was eradicated in the late 1970s. Still, smallpox exists in some freezers in the world, and could be used as an agent of bioterrorism. Also, other poxviruses such as monkeypox and cowpox still infect humans after contact with infected animals. Even though the vaccinia virus vaccine is very effective, the basis for immunity to poxviruses is not well understood.

Rift Valley fever (RVF) is a syndrome of humans caused by a viral zoonotic infection from a virus that primarily affects livestock. The virus is in the genus Phlebovirus and family Bunyaviridae. The virus is spread from animals to humans by the bite of mosquitoes. Outbreaks of RVF outbreaks occur across sub-Saharan Africa. The virus causes a spectrum of diseases, from mild fever syndromes to severe hemorrhagic disease.