Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Simple idea to dramatically improve dengue vaccinations

31.03.2006


Multi-site vaccinations could protect against all four dengue viruses



An innovative new study explains, for the first time, the failure of previous attempts to vaccinate against the four known Dengue viruses, and it suggests a very simple solution – injecting the four vaccines simultaneously at different locations on the body.
A mosquito-born disease, Dengue kills tens of thousands of people per year and sickens 100 million more. Known as "bone-break disease," Dengue is characterized by excruciating pain and was "the most important mosquito-borne viral disease affecting humans" in 2005 according to the U.S. Centers for Disease Control.

The study, from bioengineers and physicists at Rice University, appears in the March 24 issue of the journal Vaccine. The study suggests that the multi-site vaccination strategy, termed polytopic vaccination, may be effective against other diseases as well, including HIV and cancer.



Dengue infection occurs from one of four closely related viruses. Previous exposure to one of the four – either by prior infection or by vaccination – makes people significantly more likely to develop a potentially lethal hemorrhagic infection if they are later infected by one of the other three viruses.

"This is a classic case of something called ’original antigenic sin,’ which happens when our immune system becomes overly reliant upon memory when recognizing diseases similar to those that it has seen before," said lead researcher Michael Deem, the John W. Cox Professor in Biochemical and Genetic Engineering and professor of physics and astronomy. "With diseases like HIV, influenza and Dengue, our acquired immune system’s tendency to go-with-what-it-knows can leave us more vulnerable to infection from a mutant strain or a related virus. The immune system may respond less favorably in these cases than if it had never been exposed to the disease in the first place."

Original antigenic sin, or immunodominance, arises out of the procedure the immune system uses to target infection. This starts when the immune system identifies infected cells and brings pieces of them into the lymph node for targeting. Within a few days of infection, the immune system completes a massive scan of the 100 million available T-cells in its arsenal. Through a complex trial-and-error process, it identifies three to five T-cells that best recognize and attack the components of the sickened cells. Once the cells are selected, they are produced by the millions and sent out to clear the infection. After the infection is gone, thousands of these pre-programmed T-cells remain in the body, lying in wait should the disease return.

In recent years, public health officials have documented the disturbing co-existence of two or more Dengue viruses in Brazil, Cuba, Thailand, and other tropical and subtropical countries. Because sequential infection by multiple Dengue viruses can lead to increased likelihood of deadly infections, public health officials have attempted to counter the threat of co-existent versions of Dengue by developing a vaccine against all four versions simultaneously. Doctors found that patients who got a four-component vaccine wound up only being protected against one or two versions at most, due to immunodominance.

Intrigued by these results, Deem and graduate student Hao Zhou developed a precise computer model of the immune system’s biochemical scanning process to see if they could recreate the effect and find out what caused it. Their program conducts statistical calculations about the likelihood of specific interactions at the atomic level. They conducted trillions of calculations and gradually built up a bigger picture of what occurs in Dengue immunodominance.

"When faced with more than one version of the virus, the immune system may respond preferentially against the version for which it has T-cells with the strongest affinity, which is immunodominance," Deem said.

He said polytopic vaccination – giving different vaccines simultaneously at different locations on the body – could help overcome immunodominance by taking advantage of the relative isolation of lymph nodes throughout the body. Each person has hundreds of lymph nodes. Deem believes vaccinations at four different sites, served by four different lymph nodes, could allow the body to simultaneously develop immune responses against all four versions of Dengue.

"The literature about immunodominance is new and growing," Deem said. "Ours is the first model that can predict immunodominance, and when we compare our results with experimental data from Dengue vaccination trials, they match quite closely. There may be other factors at work, but we appear to be explaining a significant portion of the effect that occurs in Dengue immunodominance."

Immunodominance is also a problem for researchers working on vaccines for both the AIDS virus and cancer, each of which mutate quickly and occur in multiple strains.

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Studies and Analyses:

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

nachricht Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>