Argentine Fever Vaccine
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Argentine Fever and Junin Virus
Argentine hemorrhagic fever (AHF) is an acute infectious disease caused by Junin virus (JUNV). The first report on Argentine hemorrhagic fever began in Argentina in 1958, and the disease was named after it. Argentine hemorrhagic fever occurs almost every year, but the number of cases per year varies from 3,500 in history to 30-50 today. The incubation period of AHF is 7-14 days. The development of the disease is gradual. The initial symptoms are fever, myalgia, weakness, etc., followed by gastrointestinal, neurological, cardiovascular and other reactions. In most patients, there are cutaneous petechiae at the armpit. In the later stages of the illness, the patient may have symptoms such as irritability, lethargy, tongue tremors, ataxia, and at the end of this stage, the patient is usually accompanied by candidiasis infection. In the cases of AHF deaths, 15%-20% of patients die from deteriorating vascular or neurological damage. The overall mortality rate of the disease is 20-30%.
The causative agent of AHF, Junin virus, belongs to the family Arenaviridae. Genomes of the virus are two pieces of ambisense single-strand RNA named S (short) and L (long) respectively. S encodes glycoprotein (GP) and nucleoprotein (NP), while the L segment encodes zinc-binding protein and polymerase of the virus. Enveloped virion of the virus is encompassed with a layer of glycoproteins spike that are T-shaped, and each of which extends outward from the envelope by approximately 10 nm. These glycoproteins play an important role in mediating viral adhesion and entry into target cells. Rodents, especially Mus musculus, are hosts of the Junin virus. People got the AHF by direct contact with the excretion of JUNV infected mice.
The Development of Argentine Fever Vaccine
- Inactivated Virus Vaccines
Inactivated Junin virus vaccines prepared by various inactivation methods have problems of requiring repeated vaccination, a short-lived protective effect, and a large amount of antigen required to elicit an immune response. Improving culture conditions and methods of purification and introduction of adjuvants can increase the yield, purity, and immunogenicity of such vaccines to some extent.
- Live Attenuated Virus Vaccines
There have been some encouraging results in the development of live virus vaccines against AHF. Another member of the Arenaviridae family, a live virus vaccine prepared from a heterologous Tacaribe virus protects the animals challenged with the Junin virus, but the immune effects induced by it are shorter. The virus has been proposed as a vaccine against AHF, but there are few reports on the impact of the virus on humans. JUNV XJCI3 is a live attenuated vaccine obtained by multiple passages of the JUVN XJ strain in the MA-111 cell line. The vaccine candidate has shown long-lasting immune response in guinea pigs and is able to elicit high levels of neutralizing antibodies. Tests in humans have shown that the vaccine can cause mild subclinical symptoms while neutralizing antibodies can maintain up to 9 years in 90% of the vaccinated. XJ0 is another attenuated vaccine derived from XJCI3 showed protection in guinea pigs but later the research was discontinued because of the isolation of JUNV from vaccinated guinea pigs. A vaccine prepared from strain XJ44 has been preclinically evaluated in mice, guinea pigs, and non-human primates and its safety and good-immunogenicity have been verified. This vaccine is now being used to vaccinate humans beyond 15 years old to against infection of AHF.
- Recombinant Subunit Vaccines
Recombinant subunit vaccines are also made using vaccinia virus as vector to express glycoproteins of homologous Junin virus (VV-GJun) or of heterologous Tacaribe virus (VV-GTac), a close relative of Junin virus. Results of these two candidates showed that VV-GTac could protect 50% of vaccinated guinea pigs against JUNV challenge while VV-GJun has a 72% protection on inoculated guinea pigs after two doses of immunization. None of two vaccine candidates are capable of inducing comparable levels of neutralizing antibodies.
Creative Biolabs has many years of experience in vaccine development and has the ability to successfully develop safe and immunogenic vaccines of all types. We have a lot of advanced experience in the research of Argentine hemorrhagic fever vaccine. Whether it is vaccine design, preclinical evaluation or vaccine formulation optimization, etc., we are able to provide you with the most satisfactory service.
All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.
