The Overall Picture
development of an effective HIV/AIDS vaccine has focused on creating
either a vaccine that will protect people from HIV infection (preventive
vaccine) or a vaccine that will protect people from becoming ill after
they have already acquired the virus (therapeutic vaccine). In both
approaches, the effectiveness of the vaccine depends on its ability to
elicit a protective immune response.
Since the start of HIV vaccine research,
scientists have worked to uncover which viral antigens or combinations
of viral antigens are capable of stimulating a protective immune
response. Initially, scientists focused on outer envelope proteins such
as gp120 and gp160. While these antigens stimulated the production of
neutralizing antibodies, these antibodies appeared unable to prevent HIV
infection. Another seemingly attractive vaccine alternative is the use
of attenuated strains of HIV. Attenuated vaccines are weakened forms of
viruses that are unable to cause disease, but are still able to provoke
a powerful immune response. Recent studies on monkeys indicate that
attenuated strains of HIV may be capable of regaining virulence and use
of such a vaccine could result in disease instead of protection from
disease. Current research has expanded beyond antibody-mediated
responses to look at cellular immune responses, including how to
stimulate cytotoxic T lymphocytes (CTLs), immune cells that kill
HIV-infected cells. CD4 "T-helper" cells appear to be
important in maintaining a strong CTL response. The relative importance
of CD4, CD8, and antibody responses remains to be determined. At the
current time, researchers and policymakers face the choice of beginning
large vaccine studies without knowing which approaches are most likely
to succeed, or waiting until results from more basic research is
available to select which vaccines should be tested in large trials.
Since any vaccine trial will take several years to complete, these
choices are not easy ones.
Because they are often more effective and
affordable than drugs, vaccines play an important role in global public
health. As demonstrated by diseases like smallpox, poliomyelitis,
rabies, and diptheria, an effective vaccine can reduce the morbidity and
mortality associated with a disease as well as limit the spread of the
disease. As is true for other treatments, an HIV vaccine can slow the
HIV/AIDS pandemic only if it is accessible and affordable. At the moment
HIV/AIDS poses the greatest threat to developing countries, where high
infection rates have had a detrimental impact on economies and have
reversed gains in life expectancy. Because of this it is essential that
the issues not only of efficacy, but of accessibility and affordability,
be considered in vaccine research.
Century Vax: Vaccine advances into unexplored territory, a place
where prevention and treatment may meet By Richard Jefferys, POZ
Research on AIDS Vaccines NIAID Fact Sheet, June 1999
Years and Counting: What Will Speed Development of an AIDS Vaccine?
AIDS Vaccine Advocacy Coalition. Washington, DC. May 1999.
and Priorities for AIDS Vaccine Development by Peggy Johnston,
PhD, Assistant Director for HIV/AIDS Vaccines, NIAID & Associate
Director for HIV/AIDS Vaccines and Prevention, Division of AIDS.
Presentation with slides in Real Audio, from University of
Califonria AIDS Research Program Annual Conference, 2/26/99, San
by the Numbers: Interview with Steve Self Interviewed by Joe
Wright, HIV InSite Guest Editor. February 1999.
the Road to an HIV Vaccine Second Annual World AIDS Day
Symposium, Presented by the UCSF
AIDS Research Institute, December 1, 1998
Vaccine Moves Into Phase 3 Trials from JAMA Vol. 280, pp. 8-9,
Jul. 1, 1998
Vacuna Que Pueda Detner La Epidemia Del SIDA Alredor Del Mundo? Si
Es Posible! Por el equipo de la educación de la comunidad del
sitio de San Francisco de la red del VIH para los ensayos de la
prevención: el departamento de San Francisco de la salud pública,
sección de la investigación del VIH. Robo Guzman, escritura e
investigación; Joe Wright, editor. 1998.
Vaccine Awareness Day Special Feature, Monday May,18,1998 Press
Conference, Interview, Contact List, and AVAC Report on Progress
towards an HIV/AIDS Vaccine.
Vaccine That Stops HIV All Over The World? It Could Happen.
Community Education Team of the San Francisco site of the HIV
Network for Prevention Trials, San Francisco Department of Public
Health, HIV Research Section. Rob Guzman, writing and research; Joe
Wright, editor. 1998.
the Goal of an AIDS Vaccine Passed recommendation from the US
Presidential Advisory Council on HIV/AIDS. May 1998.
Vaccine Development R. Paul Johnson and Spyros Kalams, AIDS
Knowledge Base. Section 3.5. 1998.
Science and Pathogenesis of HIV AIDS Knowledge Base,
Section 3. 1998 Edition. Mark Feinberg, Editor.
the Development of Preventive HIV Vaccines for the World Summary
Report and Recommendation of an International Ad Hoc Scientific
Committee October 27-28, 1995. LeVal De Grace, Paris, France
Progress On HIV Vaccines Luis Santiago GMHC Treatment Issues -
Basics Bill Snow, ACT UP Golden Gate
Vaccines by Mark Bowers, San Francisco AIDS Foundation. January
of Vaccine Development April 1996
in Designing HIV Vaccines February 1996