Peter Apps and Mateus Chale
Developed by drug giant GlaxoSmithkline, the RTS,S/AS02A vaccine reduced the
incidence of serious malaria by around 40 percent over a year in children aged
between one and four, researcher Betuel Sigauque said. The development of
a vaccine has been a big target for many years, he said late on Monday at
the Manhica Health Research Centre, site of the landmark first major trials.
You have to find the best stage of the life cycle at which to stop it.
Other attempts at vaccines have attacked the wrong stage, he said.
Transmitted by mosquitoes, the malaria parasite is one of the world's biggest
killers, responsible for one in 10 deaths in developing countries and taking the
life of one African child every 30 seconds. Many families lack knowledge, drugs
or bed nets to protect themselves.
Economists say the disease costs Africa around 12-billion (about R77-billion) a
year, hampering development as families use time and money to care for sick
children and have more offspring to compensate for malaria deaths, stretching
already limited resources. Look at this child, said Sigauque, the
centre's head of clinical research, holding up the medical card of a
two-year-old girl brought to the hospital across the road. She has come in
six times already as an outpatient, twice she has been admitted. She now has a
high fever, and we must see to check if it is malaria.The child's weight chart shows that she has been failing to thrive in the last
year, her body weight to age ratio falling increasingly close to a level that
would be classed as malnutrition. Malaria may well be to blame, he said. At the
height of the rainy season in November and December, up to 250 children a day
may be bought to Manhica Hospital, a small centre 75km from the capital Maputo.
Some 50 have to be kept in overnight, and with up to 20 inpatient paediatric
beds available many have to sleep on the floor. If they make it to hospital,
only five percent will die, but doctors like Sigauque fear the figure could be
higher in isolated outlying villages with little access to healthcare.
The vaccine trials, started in 2003 with just over 2 000 infants, could offer
more hope. By end-year, researchers at the centre - a collection of single
storey huts, buildings and thatched rondavels beside the overstretched hospital
funded by the Spanish and Mozambican governments - hope to have a clearer idea
of the long-term effectiveness of the vaccine. They hope to conduct further
trials, looking at its effectiveness with younger children still, possibly
beginning later in the year, he said. Previous malaria treatments, such as
quinine or prophylactic drugs, have suffered as the parasite adapted to them and
made them ineffective.
Sigauque says that by attacking the parasite's life cycle, scientists hope it
will be more difficult for the disease to become resistant to treatment.
But reducing malaria cases by 40 percent over a year is not the same as
eradicating the disease, and Sigauque said that even if further trials were
successful the vaccine could not be used as the sole weapon against the disease.
(Source: IOL, August 10, 2005)