Featured Research

from universities, journals, and other organizations

'New' human adenovirus may not make for good vaccines, after all

Date:
August 11, 2010
Source:
The Wistar Institute
Summary:
In a new study of four adenovirus vectors, researchers show that a reportedly rare human adenovirus, AdHu26, is not so rare, after all, and would not be optimal as a vaccine carrier. As previous research has shown, a viral vector may be ineffective if the virus it is based on is common. The study supports the use of chimpanzee adenoviruses as vaccine vectors, since humans have little exposure to these viruses.

In recent years, scientists have studied the possibility of using engineered human adenoviruses as vaccines against diseases such as HIV, tuberculosis, and malaria. In this approach, adenoviruses, which commonly cause respiratory-tract infections, are rendered relatively harmless before they are used as vectors to deliver genes from pathogens, which in turn stimulate the body to generate a protective immune response.

In a new study of four adenovirus vectors, researchers from The Wistar Institute show that a reportedly rare human adenovirus, called AdHu26, is not so rare, after all, and would thus be unlikely to be optimal as a vaccine carrier for mass vaccination. As previous research has shown, a viral vector may be ineffective if the virus it is based on is common in a given population. According to the Wistar scientists, their study also supports the use of chimpanzee adenoviruses as vaccine vectors, since humans have little exposure to these viruses. Their findings were published online, ahead of print, in the Journal of Virology.

"Despite previous reports to the contrary, we find that AdHu26 commonly infects people, particularly those in Sub-Saharan Africa, the very people for whom the need for novel vaccine strategies is most dire," said senior author Hildegund C. J. Ertl, M.D., Wistar professor and director of The Wistar Institute's Vaccine Center. "HIV, malaria, and other infectious diseases take a tremendous toll in the developing world, especially in Sub-Saharan Africa, and a vaccine platform that could be used in those regions could save the lives of millions."

Scientists believe that prior immunity to human adenoviruses is what led, in part, to the failure in 2007 of the STEP trial, a large vaccine trial in the US and other countries that used an adenovirus vector as the basis for an HIV vaccine.

In the current study, Ertl and her colleagues analyzed blood samples collected from people at seven sites around the world, including Thailand, the United States, and five sub-Saharan African nations. They tested the samples to see if they contained neutralizing antibodies and responsive immune cells when exposed to AdHu26 and AdHu5, the virus used in the STEP trial. Surprisingly, neutralizing antibodies to AdHu26 were very prevalent in blood.

According to Ertl, adenoviruses are still good vaccine vectors, just not necessarily human adenoviruses. In addition to testing AdHu5 and AdHu26, the Wistar scientists also tested two adenoviruses that originated in chimpanzees, called AdC6 and AdC7. As expected, neutralizing antibodies were far less likely to be detected in human samples. Mouse studies of all four vectors demonstrated that that were similar in their ability to generate cellular immune responses.

"This study also confirms our current line of research that suggests engineered chimpanzee adenovirus vectors could be superior to related, native human adenoviruses," Ertl said. "Both human and chimpanzee adenoviruses function in similar ways, but the simple benefit is that humans are rarely exposed to adenoviruses of chimpanzee origin."

The Ertl laboratory is currently developing an HIV vaccine utilizing chimpanzee adenoviruses.

Along with senior author Ertl, co-authors from the Ertl laboratory include senior staff scientists Zhi Quan Xiang, M.D., and Xiang Zhou, M.D.; staff scientist Dongming Zhou, M.D., Ph.D.; research technician Yan Li; research assistant Ang Bian; and visiting scientists Heng Chen and Raj Kurupati, Ph.D. Co-authors also include Michael Betts, Ph.D.; Natalie Hutnick; Sally Yuan, Ph.D.; and Clive Gray, Ph.D.; of the University of Pennsylvania School of Medicine's Department of Microbiology; Jennifer Serwanga, Ph.D., of the National Institute for Communicable Diseases in South Africa; and Betty Auma, Ph.D.; and Pontiano Kaleebu, Ph.D.; of the Uganda Research Unit on AIDS in Uganda.

Funding for this study was provided through grants from the National Institutes of Health.


Story Source:

The above story is based on materials provided by The Wistar Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. H. Chen, Z. Q. Xiang, Y. Li, R. K. Kurupati, B. Jia, A. Bian, D. M. Zhou, N. Hutnick, S. Yuan, C. Gray, J. Serwanga, B. Auma, P. Kaleebu, X. Zhou, M. Betts, H. C. J. Ertl. Adenovirus-Based Vaccines: Comparison of Vectors from Three Families of Adenovirideae. Journal of Virology, 2010; DOI: 10.1128/JVI.00450-10

Cite This Page:

The Wistar Institute. "'New' human adenovirus may not make for good vaccines, after all." ScienceDaily. ScienceDaily, 11 August 2010. <www.sciencedaily.com/releases/2010/08/100811130019.htm>.
The Wistar Institute. (2010, August 11). 'New' human adenovirus may not make for good vaccines, after all. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2010/08/100811130019.htm
The Wistar Institute. "'New' human adenovirus may not make for good vaccines, after all." ScienceDaily. www.sciencedaily.com/releases/2010/08/100811130019.htm (accessed September 20, 2014).

Share This



More Health & Medicine News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
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