Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Offer New Approach For Testing Potential HIV Vaccines

20.07.2005


Emory University researchers have proposed a new design for HIV vaccine trials in animals that would more closely mimic how humans are exposed to the virus - potentially giving AIDS researchers a more effective tool in developing successful treatments to prevent HIV infection.



In the Emory study, the researchers, using computer simulations, developed an experimental design in which animals are repeatedly exposed to low doses of HIV (similar to how humans are exposed and infected). The belief that experiments involving realistically low challenge doses would require large numbers of animals has so far prevented the development of such trials, the researchers say.

Through computer simulations and statistical analysis of their virtual experiments, the Emory researchers showed that such trials would require far fewer animals than previously thought. Their research was published in the July 19 issue of the Public Library of Science Medicine.


"We demonstrate that using low doses and challenging repeatedly -- which also is more realistic because humans are typically exposed repeatedly to HIV -- represents a very promising design," says Roland Regoes, a postdoctoral researcher in Emory’s biology department and lead author of the study.

Trials in animal models have long played an essential role in evaluating the effectiveness of potential HIV vaccines and treatments. When assessing vaccine efficacy in animal models, the animals are first given the potential vaccination. They are then "challenged" (or infected) with the virus or pathogen against which the vaccine should give protection. In simian models of HIV infection, Simian Immunodeficiency Virus (SIV), closely related to HIV, is used to challenge macaques. The trials are usually conducted with very high challenge doses of the virus that result in certain infection.

"Developing a vaccine against HIV is one of the major goals of AIDS research," he says. "Our work suggests how to improve the animal models in which possible vaccines are assessed before they are tested clinically in humans. By using lower doses and challenging repeatedly, preclinical trials would be more similar to epidemiological phase III trials in humans. This allows us to optimize vaccines in preclinical trials with respect to what really matters epidemiologically."

Using a standard statistical power analysis, the researchers simulated low challenge dose experiments more than 100,000 times. The outcome of these virtual experiments was statistically analyzed in the same way a real experiment would be.

Infection with low doses has to-date not been performed very often, Regoes says, adding that a handful of research groups have already started trials using low-dose models.

"It will be interesting to study HIV infection following challenges with low virus doses, and I am certain we will be surprised in many ways by results of these studies. I believe that low-dose challenge experiments represent an interesting alternative for the preclinical assessment of vaccines," Regoes says. In addition to improving the design of preclinical trials, low challenge dose experiments may also allow AIDS researchers to investigate "immunological correlates of protection," such as how many antibodies or T cells are needed to prevent infection, he says.

Regoes conducted the study with Ira Longini of Emory’s Rollins School of Public Health, Silvija Staprans of the Emory School of Medicine and the Emory Vaccine Center, and Mark Feinberg, a researcher with Merck. They made several recommendations in the PLoS paper on how to design preclinical studies with low doses. Some of these suggestions are related to specific aspects of conducting such trials, such as how much and how often subjects should be exposed to HIV. Other recommendations aim to make preclinical trials more realistic in other important ways, such as the route of infection or the HIV strain to use.

Regoes may be contacted directly at rregoes@emory.edu.

Beverly Cox Clark | EurekAlert!
Further information:
http://www.plosjournals.org
http://www.emory.edu

More articles from Health and Medicine:

nachricht Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>