Experimental vaccine partially protects monkeys from HIV-like infection
Results from a recent study show that novel vaccine combinations can provide partial protection against infection by Simian Immunodeficiency Virus (SIV) in rhesus monkeys. In addition, in the animals that became infected, the optimal vaccine combinations also substantially reduced the amount of virus in the blood. Results from the studies were published online today in the journal Nature.
This proof-of-concept study, which tested MVA, Ad26, and Ad35 vector-based vaccines, is the first to show partial vaccine protection in the stringent animal model involving heterologous, neutralization-resistant SIVmac251 viral challenges in rhesus monkeys. Preclinical studies of vaccine candidates have typically shown post-infection virologic control, however protection against acquisition of infection has previously only been reported using less rigorous viral challenges. The new Ad26/MVA and Ad35/Ad26 vector-based vaccine regimens resulted in over 80% reduction in the per-exposure probability of acquisition of infection against repetitive challenges of SIV, a virus similar to HIV that infects monkeys.
"This study allowed us to evaluate the protective efficacy of several prime-boost vaccine combinations, and these data will help guide the advancement of the most promising candidates into clinical trials," noted lead author Dr. Dan Barouch of Beth Israel Deaconess Medical Center at Harvard Medical School and the Ragon Institute of MGH, MIT, and Harvard.
Further analysis also provided insights into the immune responses that might have provided protection, called "immune correlates." The results show that antibodies to Env (the envelope protein that makes up the outer coat of the virus) correlated with protection against acquisition, whereas both T cell and antibody responses correlated with post-infection virologic control.
"These distinct immunologic correlates likely reflect fundamentally different requirements to block establishment of infection compared with controlling viral replication after infection," said Col. Nelson Michael, director of the U.S. Military HIV Research Program at the Walter Reed Army Institute of Research and senior author on the paper.
Barouch noted that "we have clearly shown that including Env in the vaccine is beneficial." The findings also suggest that a substantial degree of protection can be achieved against stringent virus challenges, even in the absence of high levels of tier 2 neutralizing antibodies.
These new preclinical studies provide support for advancing the Ad26/MVA prime-boost vaccine candidate into clinical development. Collaborators are planning clinical testing of this HIV vaccine regimen in healthy adults at research sites in the U.S., East Africa, South Africa, and Thailand.
More information: D Barouch et al., Vaccine protection against acquisition of neutralization-resistant SIV challenges in rhesus monkeys. Nature DOI:10.1038/nature10766 (2012).
Journal reference: Nature
Provided by National Institutes of Health
- Antibodies help protect monkeys from HIV-like virus, scientists show May 05, 2011 | not rated yet | 0
- Some monkeys born with gene that protects against AIDS May 04, 2011 | not rated yet | 0
- HIV vaccine might offer survival advantage Jun 12, 2006 | not rated yet | 0
- Research reveals further progress toward AIDS vaccine Dec 14, 2009 | not rated yet | 0
- Study offers insights into failed HIV-1 vaccine trial Jul 20, 2009 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
(HealthDay)—For HIV-infected individuals with recurrent Clostridium difficile infection, fecal microbiota therapy is feasible, according to a letter published in the May 21 issue of the Annals of Intern ...
HIV & AIDS 19 hours ago | not rated yet | 0
Canadian health authorities lifted Wednesday what was effectively a ban on gay men giving blood, announcing new rules making men who have not had sex with men in the past five years eligible.
HIV & AIDS 21 hours ago | not rated yet | 1
Top AIDS scientists were optimistic Wednesday of finding a cure for the disease that has claimed 30 million lives—but said it might not work for all people.
HIV & AIDS May 22, 2013 | not rated yet | 0
The integration of mental health interventions into HIV prevention and treatment platforms can reduce the opportunity costs of care and improve treatment outcomes, argues a new Policy Forum article published in this week's ...
HIV & AIDS May 21, 2013 | not rated yet | 0
A new coronavirus has now claimed 22 lives worldwide out of 44 lab-confirmed cases, mostly in Saudi Arabia, World Health Organization officials said Thursday.
1 hour ago | not rated yet | 0
A brief visual task can predict IQ, according to a new study. This surprisingly simple exercise measures the brain's unconscious ability to filter out visual movement. The study shows that individuals whose ...
1 hour ago | 4.7 / 5 (3) | 0 |
Gaucher disease causes debilitating and sometimes fatal neurodegeneration in early childhood. Recent studies have uncovered a link between the mutations responsible for Gaucher disease and an increased risk ...
1 hour ago | not rated yet | 0 |
Scientists have uncovered a survival mechanism that occurs in breast cells that have just turned premalignant-cells on the cusp between normalcy and cancers-which may lead to new methods of stopping tumors.
1 hour ago | not rated yet | 0 |
As the human body fine-tunes its neurological wiring, nerve cells often must fix a faulty connection by amputating an axon—the "business end" of the neuron that sends electrical impulses to tissues or other ...
1 hour ago | 5 / 5 (1) | 0 |
A study by researchers at Henry Ford Hospital found "substantial evidence" that a regenerative process involving damaged nerve fibers in the spinal cord could hold the key to better functional recovery by most stroke victims.
1 hour ago | not rated yet | 0 |