Proc Natl Acad Sci USA. A nonreplicating subunit vaccine protects mice against lethal Ebola virus challenge

[Giuseppe]

[Source: Proc Natl Acad Sci USA, full text: (LINK). Abstract, edited.]

A nonreplicating subunit vaccine protects mice against lethal Ebola virus challenge [Immunology]



Phoolcharoen, W., Dye, J. M., Kilbourne, J., Piensook, K., Pratt, W. D., Arntzen, C. J., Chen, Q., Mason, H. S., Herbst-Kralovetz, M. M.

Ebola hemorrhagic fever is an acute and often deadly disease caused by Ebola virus (EBOV). The possible intentional use of this virus against human populations has led to design of vaccines that could be incorporated into a national stockpile for biological threat reduction. We have evaluated the immunogenicity and efficacy of an EBOV vaccine candidate in which the viral surface glycoprotein is biomanufactured as a fusion to a monoclonal antibody that recognizes an epitope in glycoprotein, resulting in the production of Ebola immune complexes (EICs). Although antigen?antibody immune complexes are known to be efficiently processed and presented to immune effector cells, we found that codelivery of the EIC with Toll-like receptor agonists elicited a more robust antibody response in mice than did EIC alone. Among the compounds tested, polyinosinicolycytidylic acid (PIC, a Toll-like receptor 3 agonist) was highly effective as an adjuvant agent. After vaccinating mice with EIC plus PIC, 80% of the animals were protected against a lethal challenge with live EBOV (30,000 LD50 of mouse adapted virus). Surviving animals showed a mixed Th1/Th2 response to the antigen, suggesting this may be important for protection. Survival after vaccination with EIC plus PIC was statistically equivalent to that achieved with an alternative viral vector vaccine candidate reported in the literature. Because nonreplicating subunit vaccines offer the possibility of formulation for cost-effective, long-term storage in biothreat reduction repositories, EIC is an attractive option for public health defense measures.
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[Gert van der Hoek]

Re: Proc Natl Acad Sci USA. A nonreplicating subunit vaccine protects mice against lethal Ebola virus challenge

Experimental Vaccine Against Ebola Fever Protects Mice From Deadly Virus

By Elizabeth Lopatto - Dec 5, 2011

An experimental vaccine grown in tobacco plants against deadly Ebola hemorrhagic fever protected more than 80 percent of mice given a lethal dose of the virus, and may protect humans as well, researchers said.

The vaccine, unlike previous experimental vaccines, is also stable enough to stockpile in case of bioterrorism, according to the study in the Proceedings of the National Academy of Sciences. The next step is to test it in nonhuman primates.

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The vaccine was created using a tobacco plant, by introducing a protein from the outside of the virus into the plant. The resulting product is an “immune complex,” a combination of the virus protein and an antibody, designed to spur the body’s defenses against the infection. Traditional vaccines are made from weakened or inactivated viruses.

Researchers gave the mice the vaccine along with a chemical to prompt the immune system to create more antibodies to the virus, Arntzen said.

Read more - Bloomberg

 

[Tonka]

Re: Proc Natl Acad Sci USA. A nonreplicating subunit vaccine protects mice against lethal Ebola virus challenge

http://www.sidneyrezende.com/notici...tistas+a+produzirem+vacina+contra+virus+ebola
Portuguese-English translation

Tobacco leaf helps scientists to produce vaccine against Ebola virus
SRZD Writing | Science and Health | 06/12/2011 9:39 a.m.

Researchers found what they consider to be a great alternative to the fight against Ebola virus, which causes fatal hemorrhagic fever in 90% of its victims. Most cases occur in Africa.

As outbreaks are presented in a localized way, transient and unpredictable, researchers decided to apply the vaccine only to people in adulthood, not children, as it was before.

The difficulty was in the vaccine storage because ended up being an expensive process. "If you have something you'll have to keep at temperatures of liquid nitrogen for years, hoping that there is never an outbreak, it becomes unworkable in practice," says Charles Arntzen of Arizona State University, who led the research.

The alternative found by the researchers was the tobacco leaf. Entering into the DNA of the virus in leaf, it produces a protein that makes the vaccine effective. The process would be cheaper.

The vaccine was tested in mice and the results were positive. The study was published in the journal "Proceedings of the National Academy of Sciences (PNAS).