The World Health Organization has approved a new malaria vaccine which many scientists think could be a gamechanger in battling the deadly mosquito-borne disease that kills half a million people in Africa alone every year.
Clinical trials have shown that the R21/Matrix vaccine, developed by Oxford University together with the Serum Institute of India, reduces malaria by up to 75%.
It can be manufactured cheaply and on a mass scale. The Conversation Weekly pocast spoke to investigator Adrian Hill, who is also director of the Jenner Institute at the University of Oxford, about this revolutionary vaccine.
The institute is named for Edward Jenner who developed the world’s first effective vaccine leading to the eradication of smallpox.
Hill explained that with the new vaccine researchers have seen about 75% efficacy by counting the reduction in numbers of malaria episodes over a year.
The best vaccine prior to this was about 50% over a year, and lower than that over three years, so that is a considerable increase in effectiveness.
However the biggest difference is that this vaccine can be manufactured in huge quantities very cheaply, so could be distributed to whole populations in at-risk areas like Africa.
The Serum Institute of India, Oxford’s manufacturing and commercial partner, can produce hundreds of millions of doses of this vaccine each year, whereas the previous vaccine could be manufactured at a scale of six million doses a year from 2023 to 2026, according to Unicef reports.
The third advantage is that the vaccine will be really cheap, and that the developers will be able to sell it to developing countries at a very reasonable price, probably around US$2 to US$4 per dose.
People have been trying to make malaria vaccines for over 100 years. Well over 100 vaccines have gone into clinical trials in people. Very, very few have worked to any degree.
Malaria is not a virus, it’s not a bacterium. It’s a protozoan parasite, some thousands of times larger than a typical virus. A good measure of that is how many genes it has. Covid has 13, malaria has about 5,500. This is one of the reasons that malaria is super complex.
There are different parasite forms the first of which are injected by the mosquito into the skin and rapidly go to the liver. They spend a week multiplying there, and then they go into the bloodstream. And they are hugely different during these different stages. And the parasites grow at a rate of tenfold every 48 hours, multiplying furiously.
By the time they get to a really high parasite density, you will be very unwell. Or if you’re unlucky, you will die, typically from cerebral symptoms, a coma or from being severely anaemic, because the parasites break open the red blood cells.
The great advantage of the new vaccine is that it interrupts the parasite very early in the process, even before people become sick.
Sources: Conversation Weekly pocast, BBC.