Quest for the AIDS vaccine

Allison Tonks recently made the dire but honest statement that the
AIDS epidemic requires a vaccine to stem its spread, even as this form of
medical treatment remains elusive: “A vaccine against HIV would seem the
best way to halt the AIDS epidemic … but it is as far away as ever.” In
order to bring the urgency of this statement into full light, policy-
makers need to consider not what it would cost to develop a vaccine, but
rather what it would costs global society if it fails to develop one.

While we are always learning more about AIDS treatment in the
developing world, we do know in the developed world that:

•On an annual basis, a cohort of those under ARV treatment will
develop drug resistance in the best of medical circumstances;
•That cohort will be cumulative from one year to the next;
•In time medical care costs will increase exponentially for drug resistant
patients, exceeding by several orders of magnitude the price of therapies.

According to data from the World Bank in 2004, the range of primary
HIV-1 drug resistance rates extends from 6.6 percent in Brazil to 10
percent in Spain to 15.4 percent in France and 27.7 percent in the United
States and Canada.(1) The high rates in the developed world may be
accounted for by the frequent testing of AIDS patients in highly
sophisticated healthcare systems where surveillance systems are mandatory.

Yet, this high rate may serve as a portent to what is to come in the
developing world. By the end of this year, projections are that there will
be 2 million on AIDS treatment. Many of them entered into therapy from
resource limited settings where initial testing was limited, adherence was
problematic, and substandard drugs were the first choice of treatment. As
molecular pharmacologist Dr. Terrence Blaschke has noted: “it is widely
believed that suboptimal adherence is the most important factor in
virological failure, and studies suggest 90-95% overall adherence or
greater is necessary for a durable response.” (2) This will be difficult
to achieve in resource-limited settings over the natural life span of an
AIDS patients, increasing the possibility for an early onset of drug
resistance.

If the Brazilian rate of 10% holds for the developing world, this
would mean that 200,000 will be drug resistant by 2010 and would have to
be moved to 2nd line therapies. According to Medecins Sans Frontieres, the
price of 2nd line therapies is over 20 times the price of lst line
treatment regimens.(3) However, the price of drug products is but one
barrier: the more important cost consideration lies in the increased skill
levels of the medical cadre that will be needed for those on 2nd line and
salvage therapies, such as virologists, thoracic specialists, liver
specialists, endocrinologists, dermatologists, and clinical
pharmacologists, to name but a few.

Despite the scientific barriers to the development of a vaccine, the
donor community has no other option than to pursue its development with
urgency. There is a global war on AIDS, and like other wars, which often
are a series of catastrophes followed by victor, so too must this war be
won.

The central policy issued faced by global policy makers is not that
the development of a vaccine is the most cost effective approach to AIDS
containment. Instead, by failing to assign the proper value to it, that
choice leads to a sequential increase in the number of chronically sick
people whose care and maintenance will ultimately prove financially
unsustainable for both donors and affected governments.

EndNotes

1.Debrework Zewdie, et al., ARTICLE TITLE? AIDS Resistance and
Adherence, Vol. 18, Supplement 3, the World Bank, Washington, D.C., June
3, 2004.
2.Terrence Blaschke, M.D., White Paper on Essential Medicines, Stanford
Medical School, Stanford University, California, August 2004. Unpublished.
3.Medecins Sans Frontieres, MSF AIDS Treatment Experience: Rapid
Expansion, Emerging Challenges: Briefing Document, July 2004.

Competing interests:
None declared