Glaxo has introduced a malaria vaccine that won’t eliminate the disease entirely but should reduce it by a third:
The vaccine, which GlaxoSmithKline Bio has been developing for 20 years, was tested in 2,022 children aged 1 to 4 in Mozambique, where the mosquito-borne disease is endemic.
After the children were treated with malaria drugs to get rid of any traces of the parasite, half got three shots of the malaria vaccine in three consecutive months, while the other half got other childhood vaccines.
The children were followed up for about six months and blood was taken every few weeks to check for malaria. Any new cases were immediately treated.
The researchers, led by Dr. Pedro Alonso at the University of Barcelona, found infection in 30 percent fewer children in the vaccine group than in the comparison group. The vaccine also reduced the risk of getting sick by 30 percent, the risk of getting repeated attacks by 30 percent, and cut by 58 percent the chance of developing severe malaria.
Within the comparison group, four children died of severe malaria, while none of the children who got the vaccine died of malaria.
The vaccine was most impressive in children under 2, in whom the disease is most dangerous. The vaccine reduced the number of severe malaria episodes in that age group by 77 percent.
Malaria is caused by the parasite Plasmodium falciparum, which is carried by mosquitoes. When the parasite is injected into the human body it is in a form that can only infect the liver, where it transforms and multiplies. After about a week, 10,000 daughter parasites leave the liver, now in a form that can infect red blood cells.
When one parasite invades a red blood cell, 10 pop out and in doing so, rip open the cell, killing it.
The vaccine, which targets the parasite before it invades red blood cells, is made using an antigen, a piece of a protein that sits on the surface of the parasite and can be recognized by the immune system. When the vaccine is injected, the immune system kicks into attack mode and makes antibodies.
When a mosquito later injects the parasite, the immune system recognizes it.