“HIV’, or human immunodeficiency virus, is a retrovirus that infects cells of the immune system and destroys or impairs their function. HIV infection results in the progressive depletion of the immune system, leading to immune deficiency. Acquired immune deficiency syndrome is known universally as “AIDS”.
People with cellular immune deficiency are much more vulnerable to infections such as pneumocystis carinii pneumonia, toxoplasmosis, systemic and oesophageal candidiasis and generalized herpes zoster. These, usually uncommon infections, are called "opportunistic infections", because they take advantage of the weakened immune system. The majority of people infected with HIV, if not treated, develop signs of AIDS within eight to 10 years.
According to the United Nations, 3 million people died of AIDS in 2003, and an estimated 5 million people acquired the HIV virus. The total number of people who are infected with HIV is estimated to be 40 million globally.
Over 1.6 million people were estimated to be living with HIV/AIDS in high-income countries at the end of 2003 and about 80 000 people were newly infected. An estimated 18 000 died of AIDS in 2003. The number of AIDS deaths has continued to slow in high-income countries due to the widespread availability of antiretroviral treatment.
In Japan there has been a steady increase in the number of reported HIV infections. The number of new HIV cases reported annually has doubled since the 1990s to more than 600 in 2001 and 2002. This rise has been accompanied by an increase in other sexually transmitted infections over the same period, with the rate of Chlamydia rising by over 50% among women since 1995.
According to the US Center for Disease Control & Prevention, the estimated cost of lifetime treatment for a person with HIV averages about US$155,000. Estimates are that 40,000 people are infected yearly in the USA, resulting in an annualized cost of more than $6 billion. In the last 5 years, an estimated 200,000 people have been infected with HIV, which translates to a treatment cost over the rest of their lives of US$31 billion.
During a Plenary Lecture to the World Economic Forum in January 2001, the Director General of the WHO Dr Gro Harlem Brundtland stated, “HIV prevalence rates of 10-15% - which are no longer uncommon - can translate into a reduction in growth rate of GDP per capita of up to 1% per year”.
The market size for HIV is based on the incidence of HIV infection in developed countries and the current cost of therapy. An approximate estimation of the annual cost per patient on highly active anti-retroviral therapy (HAART) is approximately US$10,000 – 12,000. Taking these costs into account, a conservative estimate of US$1,000 per vaccine course is assumed for the market size calculation.