[ad_1]
When Patrick Duffy He began his career at the Walter Reed Army Research Institute in 1991. Scientists have been trying for several years to try the first vaccine of its kind to protect against malaria. Thirty years later, the World Health Organization has finally recommended the product of this study as an intervention against malaria for children under 5 years of age in Africa. The RTS, S vaccine, also called Mosquirix, is the first vaccine to protect against parasites.
Duffy, now head of the Malaria Immunology and Vaccinology Laboratory at the National Institute of Allergy and Infectious Diseases, is excited about his potential to reduce the number of diseases that kill more than 400,000 people each year. But he is well aware that this vaccine is not a universal solution. “This prevents clinical malaria in children,” he says. But this does not stop the transmission of the parasite from mosquitoes to humans and does not protect all the vulnerable. What about pregnant women? What about elimination? he asks. “I have a feeling this is a foundation on which improvements can be made.”
Scientists from the pharmaceutical company GlaxoSmithKline (GSK) first conceived of RTS, S in the 1980s, targeting children under the age of 5, who account for more than 65% of malaria deaths. People develop immunity to the parasite with age, so adults do not get as serious as children if they are infected. This vaccine is designed to speed up this process by protecting children until their immune system is stronger.
But testing the vaccine took a long time. GSK has partnered with organizations including Walter Reed, the Bill and Melinda Gates Foundation, and clinics in seven African countries to conduct clinical trials. The European Medicines Agency has assessed the vaccine as safe and effective, after phase III clinical trials conducted by GSK from 2009 to 2011 found it to be 50% effective in preventing serious diseases. But WHO officials have not yet been convinced that it will work in the real world, as the vaccine requires four doses delivered as injections over 18 months. Thus, GSK launched an additional pilot program in 2019, testing the product in Ghana, Kenya and Malawi.
Although health ministries in each country must approve the vaccine, the WHO recommendation is highly endorsed. But increasing production to make millions of doses, organizing national health systems to distribute them, and getting financial help from nonprofits and other countries takes time. “There is still a lot of work to be done before the vaccine becomes more widely available,” said Ashley Birkett, director of the malaria vaccine initiative at PATH, a non-profit organization that helped develop the vaccine.
Malaria is a complex parasite that has evolved with humans for thousands of years. Unlike respiratory viruses such as the flu, which spreads through the air, malaria is spread by mosquitoes. They take the parasite from the blood of infected people and then bite others in the community, passing the parasite to them. While the SARS-CoV-2 virus has about 10 genes that encode 29 proteins, Plasmodium falciparum, one of the five parasites that cause malaria, has a much larger genome that encodes more than 5,000 proteins.
The parasite also has a complex life cycle. When infected mosquitoes bite someone, small spores called sporozoites enter the bloodstream and travel to the liver, where they begin to multiply, splitting into pieces. They then leave the liver in the heart, lungs and bloodstream, where they infect red blood cells and begin to make people sick with flu-like symptoms, nausea and chills. In severe cases, malaria can cause brain damage, seizures, difficulty breathing and organ failure.
[ad_2]
Source link