The International AIDS Vaccine Initiative (IAVI) is a global not-for-profit organization working
to accelerate the development of a vaccine to prevent HIV infection and AIDS. Founded in
1996 and operational in 23 countries, IAVI and its network of partners research and develop
vaccine candidates. IAVI also works to ensure that a future vaccine will be accessible to
all who need it. The IAVI Report and Vax newsletters track the latest news in the vaccine
field. These and a database of all AIDS vaccine trials and estimates of global expenditures
on vaccine research and developmentInfectious diseases traditionally evoke two public health responses - prevention and treatment.
Unfortunately, the virus that causes AIDS has proven to be much more difficult than anticipated to
defeat, forcing scientists to be innovative. HIV vaccines have proven elusive, while treatment has
required the combination of several drugs to be effective. Increasingly it is clear that a combination
of approaches, both new and old, within a comprehensive response is needed. Microbicides –
informed by what has been learned to date about HIV treatment and prevention – represent one of
the most promising new ideas to have emerged out of the pandemic. In 2005, microbicides were
hailed as one of ten new technologies poised to make an impact on reaching the health-related
Millennium Development Goals 1So what exactly are microbicides?
Microbicide is a term used to describe
not one drug or product, but a range of
substances - literally ‘microbe killers’ -
that could substantially reduce the
transmission of HIV and other sexually
transmitted infections. Similar to the
antibacterial products used in surgery,
these products would be applied
topically – in the vagina or rectum – to
neutralize HIV along with other
pathogens. Various potentially effective
mechanisms of action are being
pursued, from killing viruses and
bacteria, or setting up a chemical barrier,
to enhancing the body’s natural defence
mechanisms. A second generation of
microbicides are based on antiretroviral
drugs that disrupt HIV attachment and
replication at the site of transmission.
Microbicides could come in many forms,
including gels, creams, suppositories,
films, or in the form of a sponge or
vaginal ring. In the future, it might even
be possible to formulate a topical vaccine
in combination with a microbicide - thus
re-boosting the vaccine every time the
microbicide is applied.
Microbicides do not yet exist, but
currently five candidates are in clinical
trials to determine their effectiveness in
reducing HIV transmission. With
sufficient resources and political will,
a microbicide could be ready for
distribution in a handful of developing
countries by the end of 2010.
The urgent need for microbicides is
exacerbated by the feminization of
AIDS. Today, women are the fastestgrowing
sub-group of people living with
HIV, and most become infected through
heterosexual contact. Women,
particularly younger women, are more
vulnerable to HIV infection than men for
economic, social and biological
reasons. In South Africa for example,