Trial of malaria vaccine failed

A highly anticipated malaria vaccine did not achieve the expected results in a recent trial in children aged 6 to 12 weeks when its protective effect was only about 30%.

Dr. Jennifer Cohn, medical coordinator of Humanitarian Aid Doctors Without Borders, described this level as 'unacceptable'. It is significantly lower than the results from a last year study conducted with slightly older babies, in that it can reduce the risk of malaria by 50% (which is already much lower than Prevention of most other common vaccines).

For decades, scientists have worked tirelessly to develop malaria vaccines, a disease caused by five different parasitic species. However, they have not been able to find a drug that is really effective in preventing parasites. Worldwide, there are dozens of candidates on the list of malaria vaccines being studied. In 2006, experts from the World Health Organization WHO said that the acceptable standard for malaria vaccines could reduce at least half the risk of infection and death, and at the same time maintained for more than a year.

Although malaria is the culprit, the disease is transmitted by mosquito bites, killing more than 650,000 people each year, mainly children and pregnant women in Africa. Because there are no vaccines, the authorities can only focus on activities such as distributing mosquito nets, spraying mosquitoes or providing good medicines to people.

In the new study of more than 6,500 African children, the team found that in babies who received 3 doses of the vaccine, the risk of malaria was about 30% lower than in the untreated group. In addition, the vaccine reduces the number of malaria cases by about 26%, lasting 14 months after the injection.

Besides, they also said it is necessary to continue to analyze more detailed data to understand why the effect of the vaccine is different in different regions. For example, children born in areas where high rates of malaria may inherit some antibodies from the mother interfere with the effectiveness of vaccination.'Perhaps we should think about a vaccine targeting a certain group of children , ' said Dr. Salim Abdulla (Ifakara Medical Institute in Tanzania).

The conclusions presented at the conference in South Africa took place last Friday. This study is expected to continue until 2014, funded by GlaxoSmithKline Pharmaceutical Group (GSK) and the PATH Malaria Vaccine Research Center.

"The experiment is not yet a failure, but it could be worse later," said Adrian Hill, Oxford University, who is developing another malaria vaccine. He also noted that the Glaxo vaccine was invalidated shortly after several months.

Glaxo began the process of research and development of vaccines in 1987 and has so far invested a total of 300 million USD. 'If its effectiveness is only about 30%, large-scale implementation in Africa will face a lot of difficulties', said Genton Blaise, an expert on malaria at the Institute of Public Health and Heat. Swiss zone in Basel is also part of the WHO advisory board.

The WHO said they could not give any comment until the tests were completed.