Why is It so Hard to Find a Vaccine for AIDS?

Mary McMahon
Mary McMahon

When Acquired Immune Deficiency Syndrome (AIDS) first burst onto the public consciousness in the 1980s, many public health officials were optimistic that a vaccine for the disease would be developed by the 1990s. As the 1990s wore on with no sign of an AIDS vaccine or cure, some members of the public lost faith in the public health establishment. With numerous vaccines on the market for other diseases, the lack of a vaccine for AIDS was questioned. The reasons behind the difficulty in developing an AIDS vaccine are extremely complex, and some scientists are concerned that a vaccine may never actually be developed.

Developing an AIDS vaccine has been difficult because the disease works from within the immune system.
Developing an AIDS vaccine has been difficult because the disease works from within the immune system.

A traditional vaccine is designed to prevent disease, but not necessarily infection. The polio vaccine, for example, introduces antibodies into the human body to help it fight polio when it is exposed to the disease. Someone who has been vaccinated for polio can still be infected with polio, but the infection will not enter the nervous system and lead to polio disease. An AIDS vaccine, however, must prevent infection, because the body cannot be taught to fight the virus naturally. Since AIDS works from within the immune system, the body is unable to recognize and fight it.

Many public health advocates have shifted focus to AIDS prevention education.
Many public health advocates have shifted focus to AIDS prevention education.

Developing a vaccine which prevents infection is extremely difficult. Most experiments with a vaccine for AIDS have shown that a vaccination may be able to help stave off the progression into full-blown AIDS, but that preventing infection may prove to be a challenge. Partly this is due to the way in which AIDS works. However, it is also due to the nature of the virus itself. AIDS, unlike many other viruses which humans vaccinate against, is extremely diverse and versatile.

AIDS originally evolved in monkeys, and like other diseases of non-human origin, it mutates extremely rapidly to adjust to the differences of the human body. These rapid mutations mean that the virus changes dramatically, and that AIDS five years after the development of a theoretical vaccine will be radically different, potentially making the vaccine useless. AIDS is also broken up into several groups, or clades. Each clade contains different genetic information, and while each one has a geographic center, an effective AIDS vaccine would need to prevent infection from all clades of AIDS, because of the global nature of human interactions.

Research to develop an AIDS vaccine continues, while scientists also work on drugs which may help to treat the condition. However, many public health advocates have shifted their focus to prevention education, rather than wait for an AIDS vaccine.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


I don't know why scientists don't try other methods to cure aids. Why is it always vaccines they think of? I guess if they guide their searches into other ways typically (killing the virus with temperature, diet, etc.) there must another way. I wish I could do something but I am not a scientist. Please find a cure for AIDS.


Reverse Transcriptase makes an error every 1 in 5 nucleotides therefore leading to mutations of the virus. These mutations result in variations of the virus. Therefore, no protein will be exactly the same.


the protein is our own protein, which would result in destroying most cells.


why don't they try to aim at the protein of the virus that stays constant not the protein that keeps mutating?

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