Grouppe Kurosawa: HIV -AIDS Statistics and Background of the Problem (print)

AIDS Statistics and Background of the Problem

According to the World Health Organization, in December 2001, 40, 000,000 people worldwide have been infected with the HIV virus-37.2 million adults and 2.7 million children under the age of 15 years. 70% of the infected population live in Sub Saharan Africa, while 15% live in South East Asia. Eastern Europe, in particular Russia, has the fastest growing AIDS epidemic in the world, in part due to a high incidence of sexually transmitted diseases and intravenous drug use. Worldwide, 1 in 100 adults ages 15-49 are infected with the HIV virus. In 16 African countries, the prevalence of HIV infections exceeds 10% of the population. 48% of those infected are women. In 2001, 5 million new HIV infections occurred worldwide-14,000 per day. 3 million people died of HIV and related infections. Of this number 580,000 were children under the age of 15 years. In the United States, there are an estimated 800-900,000 people infected with HIV. 40,000 new infections occur each year. One half the infected people are younger than 25 years. The Centers for Disease Control estimates that 60% of the new infections can be traced to homosexual sex, 25% to intravenous drug use, and 15% to heterosexual sex. Of newly infected men, 50% are black, 30% are white and 20% are Hispanic. AIDS is the fifth leading cause of death in the US for men and women in the 25-44 age group. For black men and women in this age group, AIDS is the leading cause of death for men and the third leading cause of death for women.

Although current multi-drug therapies have decreased the HIV death rate by reducing the viral titer to almost undetectable levels, these drugs cost approximately $15,000 per year USD, thereby making them defacto available only to properly medically insured people in developed countries. In the US alone, it conservatively costs $100,000 to $300,000 to care for each HIV infected person over his or her lifetime. Prolonged use of multi-drug therapies will substantially increase these costs as death rates decrease. It is estimated that AIDS has cost the US economy $81 to $107 billion dollars by the year 2000 with $3-6 billion dollars being spent annually to control the infection. The cost to the world economy was estimated to reach $514 billion by the year 2000. Prophylactic drugs such as protease inhibitors and inhibitors of the viral reverse transcriptase (AZT-type drugs) have not been proven to cure AIDS nor will they stop the spread of the virus in under-developed countries. Until an inexpensive, effective vaccine and treatment protocol is developed, the HIV virus will continue to spread throughout the world unabated. Eventually, HIV will decimate the economies of countries in Africa, Asia, Southeast Asia, Eastern Europe, and South America, the very countries that desperately need both a vaccine and inexpensive treatment protocol the most yet can afford it the least.

There are more than 80 different experimental HIV vaccines being developed worldwide. In order for a vaccine to stimulate an effective immune response to the HIV virus, the immunogen or vaccine antigen must activate both the humoral (antibody-based) and cell-mediated arms of the immune system. Unfortunately, protein, peptide, and heat/chemically-killed pathogens only poorly stimulate a cell-mediated immune response because they are incapable of reproducing themselves in the body. Scientists usually agree that the best immunogen is an attenuated virus, such as the Sabin vaccine for polio. Attenuated viruses are those that can reproduce in the body without causing disease. Although attenuated HIV viral vaccines have been proposed, they have not been tested on humans for fear the virus will revert to a pathogenic form. This reversion has occurred in experimental monkey HIV vaccines. Of the 80 or more HIV vaccines in development, 75% target the viral gp160 or gp120 membrane protein. Most of these vaccines consist of purified viral proteins, while a few others are based on DNA vectors. There is serious question whether HIV vaccines based on gp160/120 can protect against the establishment of a chronic HIV infection. Since the membrane gp160 protein allows the HIV virus to recognize and infect human cells, it would be desirable to construct a vaccine that neutralized this ability. Theoretically, a vaccine that stimulated the development of so-called neutralizing antibodies against gp160 would prevent the virus from entering cells and replicating. Since viruses are obligate intracellular parasites, they are considered harmless if they cannot replicate. Dead or alive, HIV viral particles are not harmless. If a vaccine attempts to stimulate the formation of neutralizing antibodies against gp160, the vaccine will not be able to control the spread of the virus. To the contrary, the vaccine will accomplish the opposite-it will enhance the spread of the virus and its rapid progression to AIDS. Please read our essays on Why Current HIV Vaccines Will Fail and The Folly of Testing HIV Vaccine Efficacy in Chimpanzees.