Backgrounder: Bumpy road for development of AIDS vaccine

BANGKOK, Sept. 24 (Xinhua) -- Thailand announced Thursday a breakthrough in the development of an AIDS vaccine. That came as scientists discovered the first-ever AIDS vaccine that has preventive efficacy. The vaccine has 31.2 percent efficacy in reducing the risk of HIV infection.

The following is a brief review of the arduous AIDS vaccine development path.

After AIDS first drew public notice in 1981, researchers in different countries, before the latest development, had fought a losing battle in developing a vaccine.

During the anti-AIDS campaign, researchers successively developed a variety of anti-AIDS medicines. However, the drugs can't eradicate the HIV virus, which causes AIDS and has produced a series of variations.

An AIDS vaccine that can prevent HIV infection, therefore, has been regarded as the best weapon to deal with the deadly disease.

In 1997, then U.S. President Bill Clinton said his country planned to develop an effective AIDS vaccine in the coming 8 to 10years. The United States since has been zealous in developing a vaccine. Scores of vaccines underwent clinical trials but little substantial progress has been made.

Many researchers began to take pessimistic stands on whether an AIDS vaccine could be discovered. Some even thought efforts to develop a vaccine would come to a dead end.

David Baltimore, a Nobel laureate and famed AIDS researcher, pessimistically predicted that mankind can't invent an AIDS vaccine within the next 25 years, if ever, because of the virus' complex variability.

The latest progress in the race to find an AIDS vaccine received much applause around the world.

"Today marks a historic milestone," said Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition, an international group focused on developing a vaccine.

"It will take time and resources to fully analyze and understand the data, but there is little doubt that this finding will energize and redirect the AIDS vaccine field," he said in a statement.