Subscribe free to our newsletters via your
. Earth Science News .

Subscribe free to our newsletters via your

AIDS vaccines: New hope for problem-plagued path

Ethiopia to see sharp rise in orphans running households: NGO
Ethiopia will by 2010 see a four-fold increase in the number of orphaned children aged between nine and 19 who are heading families due to AIDS, poverty and conflict, a local NGO said Friday. Some 225,000 households will be run by children, up from 77,000 in 2005, Addis Ababa-based African Child Policy Forum (ACPF) said in a report. "This is going to be an explosive problem," said Assefa Bequele, the agency's director. "In some households, the oldest child is also the principal care-giver to a terminally-ill parent," said the report. Ethiopia is one of the world's poorest countries. The government estimates that 1.5 million Ethiopians are infected with HIV, while the World Health Organization says nearly 2.8 million are infected.
by Staff Writers
Paris (AFP) Nov 9, 2008
A strategic tack in the quarter-century-old effort to devise an AIDS vaccine, which last year became darkly clouded by problems, could be more promising than thought, according to a study published on Sunday.

Research -- among lab primates, not humans -- shows that a vaccine based on priming "killer" T-cells, the heavy artillery of the immune system, can work, its authors said.

This approach was massively hit by the failure last year of what seemed a highly promising candidate, a prototype called V520 developed by the US pharma giant Merck.

V520 used a modified form of a virus for the common cold as a "Trojan horse" to deliver elements of the human immunodeficiency virus (HIV) into the body to prime the immune defences.

The new research, carried out among rhesus monkeys, likewise uses a cold virus to deliver the vaccine.

But unlike the Merck vaccine, it proved emphatically that T-cells could be marshalled into action to tackle simian immunodeficiency virus (SIV), a close cousin to HIV.

When injected with a lethal dose of SIV, monkeys were able to brake replication of the virus and remained healthy for more than 500 days after infection.

T-cell vaccines are not of the preventative kind, like the vaccines for polio or smallpox, which have become famous for shielding us against microbial infection.

Instead, they are "therapeutic" vaccines, meaning that they train killer T-cells to fan out on a search-and-destroy mission after infection, slaughtering enough infected cells to keep the viral invaders in line.

AIDS first emerged in 1981. Swift progress in identifying the virus that caused it unleashed early optimism that a vaccine would quickly emerge.

Out of the 50 candidates that have been evaluated among humans, only two vaccines have made it through all three phases of trials, and both were flops.

About 30 vaccines remain in the pipeline.

They focus almost entirely on an immune-cell response rather than by priming antibodies, an approach that was the first choice for vaccine engineers but has now been largely discarded in the realisation that HIV is a viciously mutating foe.

Merck cut short the V520 trial September 2007 after it was discovered that volunteers who had prior immunity to the Ad5 strain of cold virus used in the formula were more at risk to HIV infection than counterparts who had not been given the vaccine.

"This is a controversial field right now," admitted Daniel Barouch of the Beth Israel Deaconness Medical Center of Boston, Massachusetts, who headed the study published online on Sunday in the British journal Nature.

But, he added: "Despite the disappointing setbacks in HIV-1 vaccine development this past year, our findings suggest that we're not at the end of the road when it comes to T-cell vaccines."

His team said Ad5 is one of the main viruses responsible for the common cold and many people have already encountered it.

As a result, there is no longer a sufficient immune "kick" to it, they believe.

Instead, they used a rarely-encountered cousin, rAD26, which was given a boost in a second injection later, this time using Ad5. Both modified viruses carried part of the so-called Gag surface protein of SIV to seek their immune response.

"This is an extremely important study because it shows that there is still hope for vaccines currently in the pipeline," said Bruce Walker, director of the Harvard University Center for AIDS Research (CFAR).

"It also gives the first clear indication of the level and type of immunity that will likely be needed for an AIDS vaccine to work."

Share This Article With Planet Earth DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook

Related Links
Epidemics on Earth - Bird Flu, HIV/AIDS, Ebola

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Death By Hyperdisease
Washington DC (SPX) Nov 07, 2008
It took less than a decade for native rats to become extinct on the Indian Ocean's previously uninhabited Christmas Island once Eurasian black rats jumped ship onto the island at the turn of the 20th century.

  • Flood-hit Vietnam capital moves to contain disease outbreaks
  • China rebuilds six months after quake, amid frustrations
  • Simulated Seismic Signals Could Help Save Lives
  • Death toll in southwest China rain rises to 43: state media

  • Financial crisis puts heat on Australian govt over climate plan
  • Africa left behind in Kyoto carbon offset trade: experts
  • Current warming sharpest climate change in 5,000 years: study
  • Canada to offer Obama continental climate change pact

  • New NASA Technique Measuring Glacier Driven Sea Level Changes
  • Paloma Still Intensifying And Turning Northward
  • CHRIS Satellite Imager Celebrates 7 Years Scientific Success
  • ISRO's New Satellite Could See Through Even Cloudy Sky

  • Southwall's Heat Mirror Insulating Glass
  • Fuels Of The Future May Come From Ice That Burns, Water And Sunshine
  • Six navy personnel killed in Nigeria gun battle
  • World oil prices up on OPEC chief's remarks, China stimulus plans

  • AIDS vaccines: New hope for problem-plagued path
  • Death By Hyperdisease
  • Experimental HIV vaccine may have increased infection risk: study
  • Seeing Life In Viruses

  • Coral Reefs Found Growing In Cold, Deep Ocean
  • Jogger runs mile with rabid fox locked to arm
  • Climate change pushing lemmings over the edge: study
  • India leads world in snake-bite deaths

  • White House defends last-minute deregulation push
  • Smelly effluent mars affluent Dubai's beaches
  • Study: Biosolids pose little worker risk
  • China struggling to meet environment goals: official

  • China's media workers not in good physical shape: report
  • Scientists compare human, chimp genetics
  • World's tallest man riding high after becoming a dad
  • Ancient Bone Tool Sheds Light On Prehistoric Midwest

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement