implementation of scientifically proven HIV prevention strategies is helping to
reduce the number of new infections—the annual HIV infection rate globally fell
by 22 percent from 2001 to 2011—but a great deal more must be done. Significant
scale-up of proven HIV prevention strategies coupled with the discovery of new
HIV treatment and prevention interventions are needed to achieve an end to the
global HIV/AIDS pandemic. A safe, effective and durable HIV vaccine is an
essential cornerstone to the long-term strategy to achieve this goal.
a safe and effective HIV vaccine has been a long and difficult process largely
because HIV has proven to be an especially tough target. Recent developments
with the HVTN 505
clinical trial and analyses from the HVTN 503
“Phambili” vaccine study have been disappointing, but they also
provided clear answers about investigational vaccine strategies that,
ultimately, were not effective. Still, the new directions for HIV vaccines that
have been recently initiated define our future path and will be pursued.
many projects, scientists continue to explore findings from the RV 144 HIV
vaccine study in Thailand, which, in 2009, provided proof-of-concept
that an HIV vaccine can afford a modest level of protection. Ongoing research
related to the Thai trial is providing important information about human immune
responses and other factors that may explain why the investigational vaccine
protected some trial volunteers from HIV infection but not others. Such data
will help advance researchers’ understanding of HIV’s structure and
vulnerabilities and help guide the development of future HIV vaccine
candidates. Large-scale investigational vaccine clinical trials designed to
build on the RV 144 results and create a more robust and durable level of
protection are expected to begin in two-to-three years in South Africa.
basic research, scientists are making important discoveries about broadly
neutralizing antibodies capable of disabling a wide range of HIV strains when
tested in the laboratory setting. For example, NIAID scientists recently charted the
co-evolution of HIV and a strong antibody response in an
HIV-infected study participant, who is one of the 20 percent of HIV-infected
individuals who naturally develops broadly neutralizing antibodies to the virus
after several years of infection. Their findings could help identify which
proteins to use in an investigational vaccine to induce broadly neutralizing
antibodies more quickly. In another advance, a team of NIH scientists recently
developed a new tool to identify broadly neutralizing antibodies from blood
samples, which could help speed HIV vaccine research.
interesting basic research findings have included the identification
of a new HIV-suppressing protein, called CXCL4, in the blood of
HIV-infected individuals. NIAID scientists found that CXCL4 binds to HIV in
such a way that the virus cannot attach or enter a human cell, leading to the
conclusion that it may serve to regulate viral replication in an infected
individual and, therefore, control the pace at which HIV disease progresses.
Additionally, NIAID researchers found that even though HIV
diversifies widely in infected individuals over time, the virus
strains that are passed on through heterosexual transmission often resemble the
strain that originally infected the transmitting partner. Learning more about
the characteristics of these dominant strains could help inform HIV vaccine
this HIV Vaccine Awareness Day, NIAID thanks the thousands of men and women who
have selflessly volunteered for clinical studies and the scientists and
clinicians working to find an effective HIV vaccine. NIAID shares your
commitment and will continue the important research needed to make a protective
HIV vaccine a reality.
NIAID conducts and
supports research—at NIH, throughout the United States, and worldwide—to study
the causes of infectious and immune-mediated diseases, and to develop better
means of preventing, diagnosing and treating these illnesses. News releases,
fact sheets and other NIAID-related materials are available on theNIAID website.
About the National
Institutes of Health (NIH): NIH, the nation's medical research agency,
includes 27 Institutes and Centers and is a component of the U.S. Department of
Health and Human Services. NIH is the primary federal agency conducting and
supporting basic, clinical, and translational medical research, and is
investigating the causes, treatments, and cures for both common and rare
diseases. For more information about NIH and its programs, visitwww.nih.gov.