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 24, 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 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
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