Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Experimental vaccine protects monkeys from blinding trachoma

11.10.2011
NIH - developed vaccine based on live, attenuated Chlamydia bacteria

An attenuated, or weakened, strain of Chlamydia trachomatis bacteria can be used as a vaccine to prevent or reduce the severity of trachoma, the world's leading cause of infectious blindness, suggest findings from a National Institutes of Health study in monkeys.

"This work is an important milestone in the development of a trachoma vaccine," noted Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID) at NIH. "If this approach demonstrates continued success, the implications could be enormous for the tens of millions of people affected by trachoma, a neglected disease of poverty primarily seen in Asia and sub-Saharan Africa."

In their study, published in the Journal of Experimental Medicine online, scientists from NIAID, led by Harlan Caldwell, Ph.D., describe how they tested their vaccine concept in a series of experiments. First they infected six cynomolgus macaques with the strain of C. trachomatis that they had weakened by removing a small piece of DNA. The scientists observed that the monkeys spontaneously cleared the infection within 14 days with no or minimal signs of ocular disease. The animals then were exposed twice more to the weakened strain at four- and eight-week intervals, but the animals still showed no signs of trachoma despite being infected.

According to Dr. Caldwell, this finding is particularly significant because repeated C. trachomatis infections typically lead to more severe eye disease in people. The infected animals did not develop eye disease, and they all mounted robust immune responses.

The same six macaques then were exposed to a highly virulent strain of C. trachomatis as were six other macaques in a control group that had not been vaccinated. Three of the macaques in the vaccine group showed no signs of infection or disease, and the three others showed greatly reduced infection compared with monkeys in the control group. All six macaques in the control group became infected and displayed moderate to severe eye disease that persisted for between two and four months.

Macaques are used in trachoma studies because their immune responses closely predict those of humans. The animals in the study were treated with antibiotics after completion of the experiments, and all recovered completely.

The NIAID researchers are currently exploring how they can move their vaccine into human clinical trials.

If left untreated, prolonged trachoma infection can cause a person's eyelids to fold inward, so that the eyelashes rub the eyeball and scar the cornea. This can result in impaired vision and sometimes blindness. Trachoma is treatable with antibiotics, although in many parts of the world people have limited access to treatment. Currently, there is no vaccine for trachoma. Trachoma experts estimate that approximately 1.3 million people are blind from trachoma, 1.8 million people have low vision as a result of the disease, and an estimated 40 million people have active trachoma. Trachoma is most often spread through direct personal contact, shared towels and other cloths, and flies that have come in contact with the eyes or nose of an infected person.

Chlamydia diseases include sexually transmitted infections, which can result in pelvic inflammatory disease that can cause infertility in women, as well as trachoma. According to the NIAID researchers, findings from this study also could lead to the development of a vaccine against sexually transmitted Chlamydia infections. The Centers for Disease Control and Prevention received more than 1.2 million reports of Chlamydia infections in 2009.

NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

Reference: L Kari et al. A live-attenuated chlamydial vaccine protects against trachoma in nonhuman primates. The Journal of Experimental Medicine. DOI: 10.1084/jem.20111266

Ken Pekoc | EurekAlert!
Further information:
http://www.niaid.nih.gov

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>