Mozambique malaria vaccine trials show good result

Groundbreaking Malaria vaccine trials in Mozambique have shown good results but cannot alone win the fight against one of Africa’s biggest killers, a senior research scientist says.

“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. The development of a vaccine has been a big target for many years,” said researcher Betuel Sigauque 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 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 2-1/2-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.”

COMBINED STRATEGY

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 75 km (47 miles) 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.

Provided by ArmMed Media
Revision date: June 22, 2011
Last revised: by Tatiana Kuznetsova, D.M.D.