Featured Research

from universities, journals, and other organizations

Promising Preclinical Results With Live Attenuated Avian Flu Vaccines

Date:
September 18, 2006
Source:
Public Library of Science
Summary:
Several approaches are in progress to develop vaccines against the avian flu variety of the influenza virus. Kanta Subbarao and colleagues are working on live attenuated vaccines, which have the potential to elicit a strong, broad and lasting immune response.

Several approaches are in progress to develop vaccines against the avian flu variety of the influenza virus. Kanta Subbarao (National Institutes of Health) and colleagues are working on live attenuated vaccines, which have the potential to elicit a strong, broad, and lasting immune response. As they now report in the international open-access medical journal PLoS Medicine, results from mice and ferrets (the rodent flu model of choice) are very encouraging and pave the way to testing these vaccines in human volunteers.

The researchers developed vaccines using 3 artificially constructed, weakened forms of the influenza virus. The 3 vaccine viruses were constructed using flu virus proteins other than H and N from artificially weakened (attenuated) strains of influenza. These were combined with H and N proteins from H5N1 viruses isolated from human cases during three different years: 2004, 2003, and 1997. They grew larger quantities of the resulting viruses in hen eggs, and tested the vaccines in chickens, ferrets, and mice.

In tests of safety, the study found that, unlike the natural viruses from which they were derived, the vaccine strains did not cause death when injected into the bloodstream of chickens, and did not even cause persistent infection when given through the birds' breathing passages. Similarly, while the natural viruses were lethal in mice at various doses, the vaccine strains did not cause death even at the highest dose. In ferrets, infection with the vaccine strains was limited to the upper respiratory tract, while the natural viruses spread eadily to the lungs.

In tests of protection, all mice that had received any of the 3 vaccines survived following injection with any of the natural viruses (so-called viral challenge), while unvaccinated mice died following viral challenge. This occurred even though standard blood tests could not detect a strong immune responses following a single dose of vaccine. Challenge virus was detected in the lungs of the immunized mice, but at lower levels than in the unvaccinated mice. Mice given two doses of a vaccine showed stronger immunity on blood tests, as well as almost complete protection from respiratory infection following challenge. In addition, mice and ferrets that had received two doses of vaccine were protected against challenge with H5N1 strains from more recent outbreaks in Asia that differed substantially from the strains that were used for the vaccine.

This study shows that live attenuated vaccine based on a single H5N1 virus strain can provide protection (in mice and ferrets, at least) against different H5N1 viruses that emerge years later. One of the vaccines is now being tested in human volunteers who participate in carefully conducted clinical trials.

Citation: Suguitan AL Jr., McAuliffe J, Mills KL, Jin H, Duke G, et al. (2006) Live, attenuated influenza A H5N1 candidate vaccines provide broad cross-protection in mice and ferrets. PLoS Med 3(9): e360. (http://dx.doi.org/10.1371/journal.pmed.0030360)


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library of Science. "Promising Preclinical Results With Live Attenuated Avian Flu Vaccines." ScienceDaily. ScienceDaily, 18 September 2006. <www.sciencedaily.com/releases/2006/09/060915204325.htm>.
Public Library of Science. (2006, September 18). Promising Preclinical Results With Live Attenuated Avian Flu Vaccines. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2006/09/060915204325.htm
Public Library of Science. "Promising Preclinical Results With Live Attenuated Avian Flu Vaccines." ScienceDaily. www.sciencedaily.com/releases/2006/09/060915204325.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) 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