NEW YORK (Reuters Health) - A malaria vaccine currently under development can be safely given to young infants and appears to offer strong protection against the disease, according to the results of a study conducted in Mozambique.
The finding clears the way for final-stage testing of GlaxoSmithKine Plc’s vaccine, known as Mosquirix, and increases the chance that the world will have a usable vaccine within five years.
Malaria kills one person every 30 seconds, most of them young African children. Doctors believe a vaccine, given as part of routine infant immunization, is the best hope in fighting the disease.
“These encouraging data need to be substantiated in (further) trials, but we have shown that a vaccine can reduce the risk of malaria infection in young African infants exposed to intense transmission of Plasmodium falciparum,” the parasite responsible for the disease, Dr. Pedro L. Alonso, from the Universitat de Barcelona in Spain, and colleagues conclude.
“This is a very major breakthrough,” Alonso told reporters in a conference call. “These tantalizing and unprecedented results further strengthen the vision that a vaccine may contribute to the reduction of the intolerable burden of disease and death caused by malaria.”
As reported in The Lancet, the researchers assessed the safety and effectiveness of the new vaccine in 214 infants who were randomly assigned to receive three doses of the vaccine or hepatitis B vaccine at 10, 14, and 18 weeks of age. All of the infants received other routine immunizations at 8, 12, and 16 weeks of age.
At 6-month follow-up, the number of children with serious side effects was the same in each group — 17 — the report indicates. On follow-up through March 6, 2007, a total of 31 serious events were logged in the malaria vaccine group compared with 30 in the comparison group. None of the adverse events were thought to be vaccine related.
The test vaccine appeared to produce high levels of anti-malaria antibodies. Moreover, during follow-up, 22 subjects in the malaria vaccine group were infected with the malaria parasite compared with 46 in the hepatitis B vaccine group.
Statistical analysis of these findings indicates that the new vaccine is 66 percent effective in preventing malaria. Although this figure is not as good as for some childhood vaccinations, experts believe the huge burden of malaria means the new vaccine can still save millions of lives.
The latest findings are broadly in line with a 45 percent reduction in new infections reported in 2004 when Mosquirix was given to children aged 1- to 4-years old.
SOURCE: The Lancet, October 17th online issue, 2007.