of drug toxicities, drug resistance, difficulties with ad-herence, and the high
cost of medications, the complex medica-tion regimen is often difficult for
patients to follow. In an effort to determine if
alternative treatment approaches are possible, a study is underway to examine
patients’ responses to stopping HAART therapy by monitoring their immune status
and viral load (Dybul et al., 2001). This would allow patients to move from a
continuous regimen of anti-HIV therapy to a strategy in which they discontinue
therapy for a specific period of time (ie, 7 days) and then resume therapy for
7 days. This approach is known as structured intermittent therapy. While
preliminary re-sults of the study are promising, larger studies are needed to
de-termine the effectiveness of these alternative medication regimens.
HIV infection requires not only agents that will in-hibit viral growth but also
those that will restore or augment the damaged immune system. New therapies are
needed to restore immune function, and immunologic markers need to be
identi-fied to predict the success of therapy (NIAID, 2001). Current re-search
is testing the effectiveness of interleukin-2, interleukin-12, and other
cytokines and lymphokines (NIAID, 2001).
HIV-1 is a uniquely difficult target for the
development of vac-cines (Letvin, 1998). Since HIV-1 was discovered,
researchers have been working to develop a vaccine. A vaccine is a substance
that triggers the production of antibodies to destroy the offending organism.
Most vaccines activate the humoral arm of the immune system, which stimulates
the production of protective antibodies. In addition to antibodies, B
lymphocytes take the form of mem-ory B cells. These cells do not produce
antibodies immediately but respond vigorously to subsequent exposure. Vaccines
that stimu-late the cellular arm of the immune system are being developed.
Since 1995, there have been a variety of vaccines under study using different
strategies to prevent HIV infection in animals and humans. Some researchers are
exploring whether different im-munization schedules, different schedules of
boosters, or a com-bination of several vaccines will result in stronger or more
durable responses. Creation of an HIV vaccine is feasible, but a world-wide
commitment is needed. Cooperation between all nations is necessary to develop
and commit the resources to develop the vaccine and to create and support the
infrastructure needed to facilitate testing of vaccine immunogens (Letvin,
Bloom & Hoffman, 2001).
trials began in November 2002 to test an HIV vac-cine that incorporates three
HIV subtypes that cause about 90% of all HIV-1 infections around the world. The
first phase of this yearlong trial, which is being conducted at NIH, is
examining the vaccine’s safety. Subsequent trials will be conducted to
deter-mine the immune response to the vaccines (NIH News Release, 11/13/2002).