About My Health Careers Internship MedBlogs Contact us

Merck's Failure Over HIV Vaccine Causes Widespread Dismay

by Venkatraman on September 24, 2007 at 3:28 PM
Font : A-A+

Merck's Failure Over HIV Vaccine Causes Widespread Dismay

Disappointing results for a promising anti-AIDS vaccine have dealt a major blow to international efforts to stem the spread of the devastating disease.

The announcement Friday from US pharmaceutical giant Merck that it was halting a clinical test of the HIV vaccine was greeted with dismay after high hopes had accompanied the introduction of the V520 vaccine.


"It is a huge disappointment because this vaccine has shown promise all the way through, but it's only when you get in on these big trials that you start to see how the vaccine behaves," Glenda Gray, one of the principal investigators for the clinical trial, told AFP.

"Although in earlier studies we saw beautiful immune responses, it doesn't look like this immune response translates into something that could protect people against HIV infection," Gray added from South Africa, which is home to nearly 5.5 million people with HIV, which causes AIDS.

Merck and a center funded by the US government called off further trials of the vaccine after a large-scale study found it failed to prevent infection or to reduce the amount of the virus in the bloodstream.

The trial launched in 2004 used 3,000 volunteers in the United States and Latin American countries from between 18 and 45 years of age who were at high risk of infection of HIV.

Unlike traditional vaccines that proved ineffective against AIDS, which focused on causing the immune system to produce antibodies, the V520 offered a new approach through stimulating T cells, a component of the immune system.

Earlier experiments on animals and smaller-scale tests on humans had provided encouraging results, prompting Merck and US researchers to develop the vaccine using a common cold virus to deliver three genes from the AIDS virus.

But the new strategy failed to deliver in the larger clinical trial.

"We share in the disappointment of the research and HIV communities today," said Peter Kim, president of Merck Research Laboratories, in a statement Friday.

"Sadly, developing an effective AIDS vaccine remains one of the most challenging tasks facing modern medicine."

Merck and the US researchers who oversaw the study promised to share details of the trial with other scientists.

Larry Corey, principal investigator of the HIV vaccine trials network involved in the study, said "the data from this trial will provide critical insights into this disease and future vaccine development."

While the results were disappointing, it was too early to draw conclusions about the new class of vaccine, Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases which co-sponsored the trial, told the New York Times.

The failure of the V520 vaccine illustrated how AIDS is different from other infections which scientists have developed vaccines for in the past.

The daunting search to find an anti-AIDS vaccine has involved dozens of clinical trials in recent years with tests for some 30 vaccine candidates still under way.

In May 1997, then US president Bill Clinton declared securing a vaccine in a decade a national priority, but the latest clinical tests have underlined the difficulty facing scientists.

"Creating a vaccine to prevent transmission of HIV, or at least to limit its pathogenic and epidemic potential, is one of the great challenges of our time," Bette Korber, a researcher at Los Alamos National Laboratory in New Mexico, said at a conference last year.

Since the identification of the HIV virus in 1981, the number of those infected has continued to rise with some 40 million carrying the virus. Each year brings an estimated four million new infections, of which 90 percent occur in developing countries.

Over the last 25 years, AIDS has claimed more than 25 million lives, with a majority of victims in sub-Saharan Africa.

Source: AFP

News A-Z
News Category
What's New on Medindia
Cochlear Implants may Consequently Drive Hearing Loss
E-cigarettes Use Linked to Erectile Dysfunction
Memory Loss - Can it be Recovered?
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Oral Health And AIDS AIDS/HIV AIDS/HIV - Epidemiology AIDS/HIV - Clinical Features AIDS/HIV - Health Education AIDS/HIV - Prevention And Transmission AIDS / HIV - Treatment AIDS/HIV- Lab Tests and Faqs Prostitution: Fresh Stakes in the Oldest Trade HIV Symptom 

Recommended Reading
AIDS/HIV - Epidemiology
AIDS or HIV is an epidemic disease, a potentially deadly infection that can be prevented with ......
Merck’s AIDS Vaccine Fails, Trials Halted
An AIDS vaccine trial has been halted by its manufacturers, the Merck, when some volunteers become ....
AIDS / HIV - Treatment
Encyclopedia section of medindia explains in brief about the treatment for AIDS/HIV...
"AIDS is an epidemic disease, a potentially preventable, deadly infection for which there is no cure...
AIDS/HIV - Clinical Features
Encyclopedia section of medindia gives general info about HIV Clinical Features...
AIDS/HIV - Health Education
Encyclopedia section of medindia gives general info about AIDS information and health education....
AIDS/HIV - Prevention And Transmission
Encyclopedia section of medindia explains in brief about the prevention for AIDS/HIV...
Oral Health And AIDS
AIDS has taken on massive proportions in modern times. It is estimated that over 15 million people a...
Prostitution: Fresh Stakes in the Oldest Trade
Prostitution has broadened its base to include street prostitution, massage brothels, gigolo outcall...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use