Featured Research

from universities, journals, and other organizations

Experimental vaccine protects monkeys from blinding trachoma

Date:
October 11, 2011
Source:
NIH/National Institute of Allergy and Infectious Diseases
Summary:
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 new findings from a study in monkeys.

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.


Story Source:

The above story is based on materials provided by NIH/National Institute of Allergy and Infectious Diseases. Note: Materials may be edited for content and length.


Journal Reference:

  1. L Kari et al. A live-attenuated chlamydial vaccine protects against trachoma in nonhuman primates. The Journal of Experimental Medicine, 2011 DOI: 10.1084/jem.20111266

Cite This Page:

NIH/National Institute of Allergy and Infectious Diseases. "Experimental vaccine protects monkeys from blinding trachoma." ScienceDaily. ScienceDaily, 11 October 2011. <www.sciencedaily.com/releases/2011/10/111010092746.htm>.
NIH/National Institute of Allergy and Infectious Diseases. (2011, October 11). Experimental vaccine protects monkeys from blinding trachoma. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2011/10/111010092746.htm
NIH/National Institute of Allergy and Infectious Diseases. "Experimental vaccine protects monkeys from blinding trachoma." ScienceDaily. www.sciencedaily.com/releases/2011/10/111010092746.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins