mosquito-borne diseases They are already a big problem, but it will become even worse as climate change creates optimal conditions for these insects to breed. Therefore, it is important to look for ways to prevent them, both mosquito repellent methods and mosquito prevention methods. through vaccines. But what if the best vaccine actually used mosquitoes as a kind of injection syringe? This is what some Dutch scientists have recently proven by developing malaria vaccine very special.
This disease is caused parasite Plasmodium falciparumwhich uses mosquitoes as a vector of infection. There are currently two vaccines against malaria, but their protective ability is not the best. The one that produces the most immunization does not exceed 75% efficiency. In addition, multiple booster doses are required, which is not easy to do in developing countries such as African countries, where most infections occur. Plasmodium.
For this reason, the authors of a study recently published in New England Journal of Medicine They were looking for a very original solution. It involves using populations of mosquitoes infected with genetically modified parasites so as not to cause disease, but stimulate the immune system to fight them. Thus, the malaria vaccine is administered by the mosquitoes themselves. The results of the first trial were very positive, although more research will be needed. This is what we know for now.
A very original malaria vaccine
When the malaria parasite infects human cells, it infects liver and then begins to infect red blood cells. At the same time, a large number of symptoms begin to appear, among which stand out very high fever and chills. Although headache, fatigue, diarrhea, vomiting, difficulty breathing or cough may also occur, among other things. Some symptoms are the result of anemia caused by the destruction of red blood cells.
When developing a vaccine against malaria, these scientists modified the parasites. P. falciparum in two different ways. In some, they modified their genes so that they stopped their development. one day after infection. But the representatives of the second group stopped. in 6 days.
These parasites were introduced into mosquitoes Anopheles stephensi and then a group of volunteers were subjected to it.
Small sample
They initially volunteered for the study. 75 adults who have not previously had malaria. Following initial information and testing, a total of 43 volunteers were enrolled in the malaria vaccine clinical trial. They all completed Stage A, at which they were divided into three groups. Members of the GA1 group were exposed to modified mosquito bites to stop their development for one day. On the other hand, the GA2 group received modified mosquitoes that did the same in 6 days. Finally, participants in the control group did not receive the malaria vaccine.
In Phase B, all volunteers were required to be bitten by mosquitoes containing the unmodified parasite. There were 3 volunteers who dropped out of the clinical trial after phase A, so only 40 remained, but only 20 met all the criteria to continue the study. Of these people 8 of them were part of the GA1 group, 9 were from the GA2 group and 3 were from the placebo group.
After a controlled challenge with the unmodified malaria parasite, 3 patients in the placebo group became ill, 7 of 8 in GA1, and 1 of 9 in GA2. This indicates that the parasite may have spread a little more, giving the immune system the opportunity to build up more defenses without causing disease.
Everything has its limitations
It’s logical small number of participants This is a major limitation of the study. It should also be taken into account that this is a major limitation of the study. controlled infection This is not the optimal way to develop this type of research. Of course, participants had to sign informed consent. During a controlled infection, the parasites in question were not resistant to the drugs, and the disease was treated from the initial stages. Moreover, these were young and healthy people. In Africa, where most cases occur and there is little control, the disease kills 1 in every 200 patients. Therefore, the probability of death of participants was very low.
However, if clinical trials of this malaria vaccine were conducted with a larger number of participants, it would be advisable look for other methodssuch as releasing these mosquitoes in areas where malaria is endemic. After all, that’s what you’d expect if all goes well. Infecting people in a controlled manner is much less ethical and different from what would happen in reality.
Source: Hiper Textual
