Lauren Dempsey, MS in Biomedicine and Law, RN, FISM News
According to a new study, genetically modified mosquitoes may be the key to creating a vaccine to protect against malaria.
The study was published in Science Translational Medicine in August that detailed the use of mosquitos that were infected with Plasmodium falciparum, the parasite responsible for causing malaria infections in humans, that had specific genes deleted.
The National Institute of Health study used 200 genetically modified mosquitoes to administer the vaccine to the participants, who had never had a malaria infection. Over a series of months, participants were vaccinated three to five times at 30-day intervals. The mosquitos successfully gave the participants antibodies for malaria, without making them sick, according to researchers.
In the trial, “half of the individuals in each vaccine group did not develop detectable P. falciparum infection, and a subset of these individuals was subjected to a second CHMI 6 months later and remained partially protected.” However, the vaccine was only about 50% effective and protection was extremely limited.
The researchers feel that these results are promising in terms of safety and are hopeful that “these results support further development of genetically attenuated sporozoites as potential malaria vaccines.”
NPR reported that the University of Washington physician and scientist Dr. Sean Murphy, the lead author of the paper, clarified that the mosquitos were not used with the intention of vaccinating the public. According to Murphy the choice simply came down to cost, as mosquitos were cheaper to use than syringes. The team is hopeful that they’ll be able to get the dosing correct enough to deliver the vaccine through a more traditional route and improve the efficacy.
This isn’t the first group of scientists to use insects as a vaccine. In 2010, Japanese researchers conducted experiments on mosquitos to create “flying vaccinators” for malaria and leishmaniasis, a parasite that causes organ damage and skin sores.
Some people, including biochemist and best-selling author Robb Wolf, have expressed ethical concerns with the idea of using mosquitoes to spread a vaccine, including a lack of informed consent as well as concerns that it would be impossible to determine who has been vaccinated and what dose they received.
Informed consent has largely gone the way of the 4th amendment, so I doubt too many will care too much about the implications. , Why mosquitoes were the vaccinators in a new malaria vaccine trial : Goats and Soda : NPR https://t.co/HMHtj3YbDy
— Robb Wolf (@robbwolf) October 1, 2022
According to the World Health Organization’s latest World malaria report, there were an estimated 241 million malaria cases and 627,000 malaria deaths worldwide in 2020. There were about 14 million more cases and 69,000 more deaths in 2020 compared to 2019 with about two-thirds of the additional deaths being linked to disruptions in the provision of malaria prevention, diagnosis, and treatment during the COVID-19 pandemic.
The highest transmission of malaria is found in Africa, south of the Sahara, and in parts of Oceania such as Papua New Guinea. Transmission depends on temperature, humidity, and rainfall in tropical and subtropical areas. The most vulnerable people are children and pregnant women.
Malaria is the leading cause of death and disease in many developing countries.
Last year, the WHO announced its recommendation that a malaria vaccine is administered to children in areas with moderate to high transmission rates where it is a primary cause of childhood illness and death. Currently, R21/Matrix-M is the only vaccine to show an efficacy of better than 75% in trials. However, Mosquirixis is the only malaria vaccine that currently has approval outside of the European Union.
“This is a historic moment. The long-awaited malaria vaccine for children is a breakthrough for science, child health, and malaria control,” WHO Director-General Dr. Tedros Adhanom Ghebreyesus said. “Using this vaccine on top of existing tools to prevent malaria could save tens of thousands of young lives each year.”
Antimalarial drugs and mosquito control programs have historically played a key role in controlling malaria in endemic areas and have significantly reduced where malaria occurs.