Researchers at the National Institutes American Health (NIH) have created the malaria vaccine more effective so far. In a phase 1 clinical trial, which in principle is only intended to evaluate the safety of treatment, none of the six volunteers who received five doses has contracted malaria after a year, in comparison, of the six volunteers who received placebo, five contracted the disease, and those receiving lower doses showed intermediate protection. Numbers are small but significant and hopeful. The vaccine is far from perfect, as it requires at least five intravenous injections, but the main specialists consider it a major breakthrough.
Malaria kills about 2,000 people a day, according to the latest estimates from the World Health Organization (WHO) with data from 2010. Current vaccines have limited efficacy, and the search for a drug that offers good protection against infection has been a nightmare for researchers for nearly half a century.
The only method that offers a truly effective and lasting protection, known to scientists for 40 years, is actually the work of Mother Nature. The main causative agent of malaria is the single-celled (protozoa), Plasmodium falciparum, which is transmitted to humans by the bites of mosquitoes of the genus Anopheles. But there is a plasmodium, called sporozoite, which infects the salivary glands of Anopheles, and when you let the mosquitoes bite to healthy people, they are permanently protected against pathogenic forms of the parasite. This is the key that has allowed us to develop the new vaccine.
The disease kills about 2,000 people a day in the world
Robert Seder, the
Much remains to be done, but it seems paved the way for a breakthrough
“The results indicate” according to the authors, “there is a threshold dose-dependent immune to establish a high-level protection against malaria, and that this threshold can be achieved by intravenous administration of a vaccine that is safe and meets with health regulations. ” A single force protection that had achieved so far with the old method of mosquitoes, a strategy that would be more difficult to implement even the five intravenous doses.
In any case, scientists admit that much work to be done to clarify beyond a year, how long the protective effect: if one were to inject five times a year for the entire population for the rest of his life, technical and economic obstacles would be formidable. Even if enough with injections of the first year, the fact that they are injecting, rather than the usual intramuscular, intradermal or nasal-would be a challenge for health systems in poor countries affected.
But the way seems open for a health breakthrough of extraordinary importance.
Few people in the world better able to assess how difficult it is to get a malaria vaccine that Pedro Alonso. This researcher, alternating his work between the Centre for International Health Research (CRESIB, funded among others by ISGlobal) and Africa-serving COUNTRY from Maputo, capital of Mozambique, has been in recent years the biggest star of this field with a job you got, among others, the support of the Bill and Melinda Gates Foundation. But after a promising start, the last tests of its prototype, with protection rates of only 31% in children, put a shadow on his work.
Despite this disappointment, Alonso is full of praise for the work of Hoffman and his team. “It is very positive. I’ve known them for 20 years and have worked with them. The key point is the proof of concept that you have to work, “he says.
refers to the idea of ??this new vaccine model uses an idea “that was used in the sixties and seventies, but it proved unfeasible”. Then sporozoites were not used (one form of the plasmodium that causes malaria) irradiated to weaken, as now. “He radiated mosquitoes, but was stung when the immunized people,” said Alonso.
But that was not feasible. “Hoffman has started from the idea, but instead of using mosquitoes, has managed sever their salivary glands, which is where the parasite, and remove it. And has gotten in a protection group six six, which is a full protection. “
The drawback is that the method is very applicable in the field, and from someone who has spent decades in Africa, the continent most affected by malaria. “So I say it is a proof of concept to be refined.”
There are two main drawbacks: first, that the system that has given the best results you need five intravenous injections, “a much more complicated than a pill or intramuscular injection. We must reduce the dose, seek new routes of administration, “says Alonso. The second is that parasites thus obtained must be kept at 200 degrees Celsius, “liquid nitrogen”, a technique that involves handling and storage problems.
Alonso, however, is optimistic. “I recently spoke with Anthony Fauci [director of NIAID, National Institute of Allergy and Infectious Diseases of the United States], and the expectations and enthusiasm are at 100%.” ??
No comments:
Post a Comment