Malaria vaccine's failure shows glimmer of hope

A new blood-stage malaria vaccine may have recently failed to prevent clinical infection in a randomized trial, but investigators hope that the product could be helpful in the creation of a multicomponent vaccine.

The vaccine, based on a Plasmodium falciparum antigen, offered some protection against infection with P. falciparum containing apical membrane antigen 1 found on a strain of the malaria parasite, but not a strain identical to what researchers had hoped, according to

"AMA1 might be useful in a multicomponent malaria vaccine," Dr. Christopher Plowe of the University of Maryland said, reports.

A vaccine previously based on AMA1 fared even worse in trials in Mali, showing no evidence of efficacy, even among a specific strain of the tropical illness.

The current study combined the recombinant AMA1 protein with an adjuvant called AS02, which was developed by pharmaceutical giant GlaxSmithKline.

In the study, 400 healthy Malian children aged one to six years old were followed for six months after receiving either three monthly doses of the vaccine or a rabies vaccine that served as the control. Clinical infection occurred in 48.8 percent of the children who received the malaria vaccine and in 54.4 of those who received the rabies vaccine.

The vaccine was much more effective when counting infections with parasites carrying AMA1 proteins similar to the one used to create the vaccine.