Lecture highlights AIDS week events

Sam Avrett, co-founder of AIDS Vaccine Advocacy Coalition, presented a lecture entitled “The Push for a Vaccine: HIV/AIDS in 2002” last Wednesday. In his talk, Avrett outlined the science and politics of HIV-vaccine research and discussed the important role of advocates in the search for a vaccine.

Avrett urged all Americans to act as advocates in the search for a vaccine against HIV. “Think globally, act locally,” he said. He continued by stating that advocacy has an important role to play in fighting the AIDS epidemic by building awareness and providing accurate information that enables independent judgment and action. Behavioral change can be a powerful means of protecting individual health and, ultimately, perhaps ending the HIV epidemic.

Avrett explained that the need for action is pressing. The total global number of persons infected with HIV was 33.6 million in 1999, and more than 16,000 new people are infected daily. The scale of the epidemic is greatest in sub-Saharan Africa and Asia, but no part of the world is unaffected.

An HIV vaccine will be one weapon among a vast arsenal in the battle against HIV and AIDS. Other methods include safe medical practices, education and the alleviation of societal factors like poverty and inequality that predispose individuals towards behavior that puts them at risk of infection.

Despite the promises of a vaccine, many people are ambivalent about its development, Avrett claimed. It may encourage the tendency of individuals to consider themselves not personally at risk of infection and thus reduce their motivation to act as advocates for the cause. The stigma of being seen as at risk of infection may also discourage people from wanting to use a vaccine. Moreover, distrust of government, industry and researchers may give rise to doubt about the efficacy or safety of the vaccine.

The development of an HIV vaccine would provide a more cost-effective alternative to existing prevention strategies, Avrett said. A vaccine “teaches” the body’s immune system to recognize and defend against invaders, such as HIV cells, by injecting dead or weakened disease cells, or parts of these cells, into the body. Vaccines can be preventative or therapeutic, and the ideal HIV-vaccine would be one that achieves “sterilizing immunity.”

Once vaccinated, subjects would be protected from infection for life and thus unable to pass the disease on to others. Failing this, another type of vaccine might reduce infection by HIV to a “transient infection,” whereby HIV cells are quickly destroyed by the patient’s own immune system.

By reducing the time period in which HIV cells are active in the body, this vaccine would diminish the risk of transmission of the disease to others.

A third possibility is a vaccine that would not prevent infection or completely destroy HIV cells in the body, but would instead result in a “long-term controlled infection.” In this case the “viral load” of HIV cells in the bloodstream would be kept very low, preventing the onset of AIDS and reducing the risk of transmission.

There is much reason to be optimistic about the future of the search for an effective HIV-vaccine. The smallpox vaccine led to the eradication of this disease worldwide. Optimists believe a similar result is possible in the case of HIV. “The science is there,” Avrett claimed. The difficulty now is to determine the most effective mixture of fragments of HIV cells to be used in the vaccine, a process that will require extensive testing.

The standard time frame for the development of a vaccine is between 16 and 20 years. For example, the time lapse between the discovery of the cause and the development of a vaccine was 18 years for Lyme disease and 20 years for Hepatitis B. The case of the HIV-vaccine is further complicated by the variability of the disease. Many different strains of the virus exist, so to develop an effective vaccine, scientists must determine which structural components are common to all of them.

This is where the need for advocacy arises. The testing process can be streamlined by the parallel development ? the testing of several different possible mixtures of components at once. This will require the coordination of the several different institutions currently involved in research and development for an HIV-vaccine.

The major players in vaccine development fall into three categories: national governments, of which the USA, the UK, France and South Africa have been particularly active; industry, including companies that between them manufacture most of the world’s industries, such as Aventis Pasteur Merck, Wyeth and GlaxoSmithKline, as well as smaller biotech companies; and private charities such as the Gates Foundation, the Rockefeller Foundation, IAVI and several more.

Industry in particular faces serious barriers to coordinating its efforts due to monopoly laws that prohibit collusion. A central, independent body is needed to coordinate the efforts of these various groups, streamlining the development process and insuring it is carried out in an ethical manner. With its help, Avrett claimed, an HIV-vaccine could be possible within the next five to 10 years.

Advocacy is also needed to boost funding. Spending on HIV research has been rising, with the global annual total reaching $19 billion last year, but more is still needed. Most of this money is spent on care of infected patients. Only $350 million was spent on vaccine research last year. That is roughly equal to the funding of three Hollywood movies.

U.S. federal spending on HIV-vaccine research increased under the Clinton administration. The budget of the National Institute of Health (NIH) for this purpose has grown from $49m in 1992 to $250m in 2000. The attitude of the Bush administration towards HIV-vaccine research is unclear, however, and the vaccine lobby is nervous of drawing federal funding away from other methods of combating HIV and AIDS, as well as research and development programs associated with other diseases such as cancer and heart disease.

Avrett hopes to approach the Bush administration in conjunction with these other interest groups in an effort to increase spending on HIV-vaccine research “as part of the pot.” Industry spending needs to be increased as well, and Averett suggested that tax and patent incentives could have a major impact on commercial investment in HIV-vaccine development.