Just as Africa is beginning its first AIDS vaccine trial with Phase I testing
of Pasteur Merieux Connaught's canarypox vaccine in Uganda, the South African
government has drawn up a plan to develop its own, national HIV vaccine. A
preliminary proposal for this effort, obtained by Nature Medicine,
shows that the South African AIDS Vaccine Initiative (SAAVI) estimates this
process will take at least seven years. However, SAAVI is predicting that
it will have a vaccine candidate in clinical trials within two years, and
has budgeted R50 million (US$8.3 million) for this first phase of development.
The initiative was prompted by concerns that international efforts to develop
a vaccine will result in a product not suitable for the HIV subtype prevalent
in southern Africa, clade C. Their case is illustrated by the canarypox vaccine
being used in the Ugandan trial which targets clade B—the predominant
subtype found in the US and Europe. SAAVI also contends that a nationally
manufactured vaccine will circumvent the potential affordability and accessibility
problems associated with foreign-made alternatives.
Anthony Fauci, director of the US National Institute of Allergy and Infectious
Diseases which is sponsoring the Ugandan trial, supports South Africa's attempt
to develop their own vaccine, but disagrees that cross-clade reactivity does
not occur. "Examination of cytolytic T cells from people vaccinated with a
B clade epitope, as well as people infected with a variety of different clades,
shows that there is a degree of cross-reactivity," Fauci explains. He concedes,
however, that cross-clade reactivity is not guaranteed. "If it turns out [in
the Ugandan trial] that there is no cross-reactivity...that is also important
information which will direct future vaccine development." He adds that the
trial will also be vital to testing and building the country's infrastructure
for future, full-scale vaccine trials.
SAAVI partners include South Africa's national power company, Eskom, which
has promised financial support in light of HIV's long-term economic impact
on industry: Eskom estimates that by 2005, new AIDS cases within its organization
will add R300 million to business costs.
SAAVI will be directed by a steering committee, most likely headed by the
Director General of Health, Ayanda Ntsaluba. This committee will, in turn,
answer to the government's Interministerial Committee (IMC) on AIDS, chaired
by deputy president Thabo Mbeki. As the primary sponsor of the program, the
government will hold the intellectual property rights to any vaccines produced,
and government control of the program is stressed in the SAAVI proposal: "At
all stages the IMC must ensure political oversight over the scientific process."
Thus, under this agreement, scientific input is relegated to the third
tier of the SAAVI management structure and comprises a Scientific Advisory
Committee made up of local and international experts. Those rumored to be
on the invitation list for the committee include Peggy Johnston, assistant
director for HIV/AIDS at the National Institute of Allergy and Infectious
Diseases; Andrew McMichael from Oxford University and José Esparza
of UNAIDS.
Research will be coordinated by the South African Medical Research Council
(MRC). William Makgoba, MRC president, would not be drawn on the specific
type of vaccine that the group will pursue: "SAAVI will use several approaches
as a basis for the vaccine. At the moment four candidate approaches are being
developed and others are being considered." He denies that the initiative
will overlap with international efforts and draw upon their resources. "SAAVI's
efforts are an addition rather than a duplication. Because we shall be targeting
clade C, a strain that other countries are not focusing on, we shall be adding
to...the global effort. We can no longer claim independence and equally not
take responsibility for our national woes or wait for somebody to resolve
issues for us."
Former MRC president Walter Prozesky says that South Africa has the necessary
vaccine development and production experience, borne of years of apartheid
sanctions and isolation, to support the project. "We eradicated polio from
this country with our own vaccine after being one of the first five countries
in the world to start vaccination...and have been making our own DPT for 30
years. Furthermore we were one of the first countries in the world to make
a diploid rabies vaccine."
The South African cabinet is expected to announce the creation of SAAVI
within the next few weeks, and government funding should be released on April
1st.
