Hepatitis A is an infectious disease of the liver caused by the hepatitis A virus (HAV).
 Many cases have few or no symptoms, especially in the young.
 The time between infection and symptoms, in those who develop them, is between two and six weeks.
 When symptoms occur, they typically last eight weeks and may include nausea, vomiting, diarrhea, jaundice, fever, and abdominal pain.
 Around 10–15% of people experience a recurrence of symptoms during the six months after the initial infection.
 Acute liver failure may rarely occur, with this being more common in the elderly.
Barley yellow mosaic virus is plant pathogenic virus that causes the yellow mosaic disease of barley.
 Its shape is categorized as being flexuous filamentous, with lengths of 275 and 550 nanometers.
 The virus has a limited host range, and barley appears to be the only known susceptible host.
 The virus is transmitted via "Polymyxa graminis", which is a plasmodiophorid protist, through the resting spores that survive in the soil, and eventually zoospores.
 Eastern Asia is the most affected region, but the virus can be found worldwide.
 Current agricultural practices have been ineffective at eliminating the virus, but breeding resistance appears to be the only way to help reduce the disease.
Infectious hematopoietic necrosis virus (IHNV), is a negative-sense single-stranded, bullet-shaped RNA virus that is a member of the "Rhabdoviridae" family, and from the genus "Novirhabdovirus".
 It causes the disease known as infectious hematopoietic necrosis in salmonid fish such as trout and salmon.
 The disease may be referred to by a number of other names such as Chinook salmon disease, Coleman disease, Columbia River sockeye disease, Cultus Lake virus disease, Oregon sockeye disease, Sacramento River Chinook disease and sockeye salmon viral disease.
 IHNV is commonly found in the Pacific Coast of Canada and the United States, and has also been found in Europe and Japan.
 The first reported epidemics of IHNV occurred in the United States at the Washington and the Oregon fish hatcheries during the 1950s.
Marek's disease is a highly contagious viral neoplastic disease in chickens.
 It is named after József Marek, a Hungarian veterinarian.
 Marek's disease is caused by an alphaherpesvirus known as 'Marek's disease virus' (MDV) or "Gallid herpesvirus 2" (GaHV-2).
 The disease is characterized by the presence of T cell lymphoma as well as infiltration of nerves and organs by lymphocytes. Viruses "related" to MDV appear to be benign and can be used as vaccine strains to prevent Marek's disease.
 For example, the related Herpesvirus of Turkeys (HVT), causes no apparent disease in turkeys and continues to be used as a vaccine strain for prevention of Marek's disease (see below).
 Birds infected with GaHV-2 can be carriers and shedders of the virus for life.
 Newborn chicks are protected by maternal antibodies for a few weeks.
 After infection, microscopic lesions are present after one to two weeks, and gross lesions are present after three to four weeks.
 The virus is spread in dander from feather follicles and transmitted by inhalation.
Firdausi Qadri (born March 31, 1951) is a Bangladeshi scientist with specialization in immunology and infectious disease research.
 She has worked over 25 years on the development of vaccines for cholera and has expertise on other infectious disease like ETEC, Typhoid, "Helicobacter pylori", rota virus, etc.
 Currently, she is working as a director for Centre for Vaccine Sciences of International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b).
 Her scientific achievements lie in enteric and diarrheal infections and vaccines including Vibrio cholerae and enterotoxigenic Escherichia coli—major causes of severe diarrhea as well as enteric disease.
 She has also focused on studying the immune response in H.pylori infected people in Bangladesh and the responses in patients with typhoid fever as well as vaccinees.
Reston virus (RESTV) is one of five known viruses within the genus "Ebolavirus".
 Reston virus causes Ebola virus disease in non-human primates; unlike the other four ebolaviruses, it is not known to cause disease in humans, but has caused asymptomatic infections.
 Reston virus was first described in 1990 as a new "strain" of Ebola virus (EBOV).
 It is the single member of the species "Reston ebolavirus", which is included into the genus "Ebolavirus", family "Filoviridae", order "Mononegavirales".
 Reston virus is named after Reston, Virginia, US, where the virus was first discovered.
An arenavirus is a virus which is a member of the family Arenaviridae.
 These viruses infect rodents and occasionally humans; arenaviruses have also been discovered which infect snakes.
 At least eight arenaviruses are known to cause human disease.
 The diseases derived from arenaviruses range in severity.
 Aseptic meningitis, a severe human disease that causes inflammation covering the brain and spinal cord, can arise from the "Lymphocytic choriomeningitis virus (LCMV) infection".
 Hemorrhagic fever syndromes are derived from infections such as Guanarito virus (GTOV), Junin virus (JUNV), Lassa virus (LASV), Lujo virus (LUJV), Machupo virus (MACV), Sabia virus (SABV), or Whitewater Arroyo virus (WWAV).
 Arenaviruses are divided into two groups: the Old World and the New World viruses.
 The differences between these groups are distinguished geographically and genetically.
 Because of the epidemiological association with rodents, some arenaviruses and bunyaviruses are designated as roboviruses.
Ian David Gust AO MD, BS, BSc, DipBact, FRCPA, FRACP, MASM, FT (born 15 January 1941) is an Australian medical researcher, virologist, and former science administrator.
 Gust's area of work is in the development of drugs and vaccines against viral diseases and he is best known for the development of vaccines against the Hepatitis A virus.
 He currently serves as a non–executive company director and consultant.
The human T-lymphotropic virus, human T-cell lymphotropic virus, or human T-cell leukemia-lymphoma virus (HTLV) family of viruses are a group of human retroviruses that are known to cause a type of cancer called adult T-cell leukemia/lymphoma and a demyelinating disease called HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP).
 The HTLVs belong to a larger group of primate T-lymphotropic viruses (PTLVs).
 Members of this family that infect humans are called HTLVs, and the ones that infect Old World monkeys are called Simian T-lymphotropic viruses (STLVs).
 To date, four types of HTLVs (human T-lymphotropic virus 1 [HTLV-I], human T-lymphotropic virus 2 [HTLV-II], HTLV-III, and HTLV-IV) and four types of STLVs (STLV-I, STLV-II, STLV-III, and STLV-V) have been identified.
 HTLV types HTLV-1 and HTLV-2 viruses are the first retroviruses which were discovered.
 Both belong to the oncovirus subfamily of retroviruses and can transform human lymphocytes so that they are self-sustaining in vitro.
 The HTLVs are believed to originate from intraspecies transmission of STLVs.
 The original name for HIV, the virus that causes AIDS, was HTLV-III.
 The HTLV-1 genome is diploid, composed of two copies of a single-stranded RNA virus whose genome is copied into a double-stranded DNA form that integrates into the host cell genome, at which point the virus is referred to as a provirus.
 A closely related virus is bovine leukemia virus BLV.
Entebbe bat virus in an infectious disease caused by a "Flavivirus" and is closely related to yellow fever.
 Entebbe bat virus is a (+) single-stranded RNA (ssRNA) genome virus.
 It is an enveloped virus with icosahedral nucleocapsid.
 Its genome has approximately 10,000 to 12,000 kilobases.
 Entebbe bat virus was first isolated from a little free-tailed bat ("Chaerephon pumilus") in Uganda in 1957, but was not detectable after initial isolation.
 In 2011, Entebbe bat virus was isolated from a free-tailed bat captured from the attic of a house where it had been originally found.
 Infectious virus was recovered from the spleen and lung, and the viral RNA was sequenced and compared with that of the original isolate (Kading et al. 2015).
 Not much is known about the symptoms that the virus causes, and it is unknown if the virus can infect humans.
 Entebbe bat virus was initially a mosquito-borne pathogen that was able to infect bats and use them as reservoirs for the virus.
 However, the virus does not seem to have any existing adverse side effects on its host.

Question: The virus the development of vaccines against which Ian Gust is best known for causes a disease of what organ?
Answer: liver