Friday, October 15, 2004
Malaria Vaccine at last?
The web has been buzzing all day about the discovery of a seemingly viable vaccine for Malaria. On this blog, I have often commented on the worldwide efforts being made to conquer Malaria, a disease that kills over a million people every year, the large majority of them children. Specifically, I have posted on the use of artemisinin and DDT. Given my interest in the subject, I was truly thrilled to hear about the possibility of a new vaccine. Though the vaccine had a success rate that was not very high, even partial protection (especially for children) must be considered a big step forward.
A malaria vaccine, one of the holy grails of tropical medicine, has proved surprisingly elusive. Health authorities have been fighting malaria since the Panama Canal was a gleam in Theodore Roosevelt's eye. Until the Gates foundation arrived, work on vaccines for tropical diseases had languished for decades because they make little profit for drug companies. (The world spends about $400 billion a year on drugs, but only about $8 billion on vaccines.) The American military, which also does malaria research, had limited amounts of money for it.
The Glaxo vaccine, known as RTS,S/AS02A, has been in development and testing for 17 years, said Dr. Joe Cohen, one of its inventors. It fuses a bit of hepatitis B virus with a bit of the falciparum strain of the parasite, which is the most common, and usually the most deadly, form of malaria. The piece of the parasite is from the life stage that is injected by mosquitoes, so antibodies and white blood cells stimulated by the vaccine attack before the parasite can settle in the liver and reproduce. Pieces of the hepatitis virus were added because they provoke strong immune responses, Dr. Cohen said. (Another malaria vaccine candidate uses a weakened version of a smallpox vaccine to do the same.) The goal, he said, is to create immunity that lasts longer than natural immunity, which fades in adults after they move out of malaria areas.
The results - to be published tomorrow in the British medical journal The Lancet - were comparable to or better than other methods of preventing infection in African villages, like distributing mosquito nets and insecticides.The trial was conducted by the biologicals division at Glaxo and the Mozambique Ministry of Health, with financing from the Malaria Vaccine Initiative, which was created in 1999 with $50 million from the Gates foundation.
A malaria vaccine, one of the holy grails of tropical medicine, has proved surprisingly elusive. Health authorities have been fighting malaria since the Panama Canal was a gleam in Theodore Roosevelt's eye. Until the Gates foundation arrived, work on vaccines for tropical diseases had languished for decades because they make little profit for drug companies. (The world spends about $400 billion a year on drugs, but only about $8 billion on vaccines.) The American military, which also does malaria research, had limited amounts of money for it.
The Glaxo vaccine, known as RTS,S/AS02A, has been in development and testing for 17 years, said Dr. Joe Cohen, one of its inventors. It fuses a bit of hepatitis B virus with a bit of the falciparum strain of the parasite, which is the most common, and usually the most deadly, form of malaria. The piece of the parasite is from the life stage that is injected by mosquitoes, so antibodies and white blood cells stimulated by the vaccine attack before the parasite can settle in the liver and reproduce. Pieces of the hepatitis virus were added because they provoke strong immune responses, Dr. Cohen said. (Another malaria vaccine candidate uses a weakened version of a smallpox vaccine to do the same.) The goal, he said, is to create immunity that lasts longer than natural immunity, which fades in adults after they move out of malaria areas.
The results - to be published tomorrow in the British medical journal The Lancet - were comparable to or better than other methods of preventing infection in African villages, like distributing mosquito nets and insecticides.The trial was conducted by the biologicals division at Glaxo and the Mozambique Ministry of Health, with financing from the Malaria Vaccine Initiative, which was created in 1999 with $50 million from the Gates foundation.
