If Oxford vaccine researcher Adrian Hill has his way, the first highly effective vaccine against malaria could be approved as early as next year. Hill and other researchers from the UK and Burkina Faso released the latest data on their vaccine candidate on Thursday. Accordingly, the vaccine, called R21, protected children who had been vaccinated four times 80 percent better against diseases than the young subjects in the control group who had received a rabies vaccine for comparison. The value was determined one year after administration of the fourth vaccine injection. In the past year the team presented the results after the administration of three doses: The effectiveness of the vaccine was 77 percent and thus exceeded the target of 75 percent effectiveness set by the WHO for the first time.
The new ones in the journal Lancet Infectious Diseases published results also showed that the fourth dose had once again significantly increased the antibody levels. The children continue to be observed. So far it does not look as if the effect will wear off very quickly, the scientists explained at a press conference.
The vaccine has so far been tested on more than 400 children aged five to 17 months in Burkina Faso and has been described as well tolerated. The latest results come from a phase 2 study. The third and final phase of the study with almost 5,000 children is already underway and should be completed in the coming year, it said.
Hill, director of the Jenner Institute at Oxford University, who was also one of the developers of Astra-Zeneca’s Covid vaccine, was optimistic that the vaccine could soon be used for smaller children. Children under the age of five are most at risk of dying from the fever. Every year, the disease kills more than a quarter of a million children in Africa alone. Hill thinks it’s possible that R21 could reduce that number by up to 70 percent in the coming years.
A predecessor vaccine was less effective
However, by then not only the current study results have to be confirmed, but also a whole series of other questions have to be clarified. For example what will become of the previous vaccine. The product from Oxford is based on a vaccine called RTS,S or Mosquirix, which was developed over decades by the pharmaceutical company GlaxoSmithKline (GSK). A year after being given four doses, it had shown 56 percent effectiveness. But three years later, its effectiveness had dropped to a sobering 36 percent. However, the WHO recently recommended the vaccine for use in Africa. Start-up financing has already been promised. So is this going to be obsolete anytime soon?
Hill countered that the company did not see itself as a competitor to GSK. “Two vaccines are much better than one and a lot better than none, as is currently the case.” So one could fall back on the second vaccine if not enough could be produced by the other.
How quickly and at what price the new product could be manufactured is also still open. The Oxford team works with the Serum Institute of India, the world’s largest manufacturer of vaccines. Hill promised the company would be able to produce 200 million cans a year. Your goal, however, is to have production facilities in Africa. But they don’t exist yet.
It takes money not only to manufacture but also to distribute the vaccine.
Hill estimated the cost at “a few dollars a dose.” He cited the fact that three billion dollars flow into the fight against malaria every year – mainly into bed nets, indoor insecticides and medicines. The vaccinations, however, are very likely to be more effective than these measures. However, according to Hill, the established interventions would have to remain in force; the cost of the vaccines would be on top of that.
And it’s not just about money for production, but also for the logistics of the vaccination campaigns. This is especially true since R21 seems to derive part of its good effectiveness from the fact that it was administered just before the malaria season. Poorer countries need support if future vaccinations also have to be carried out in this tight time window of just three months, said parasitologist Halidou Tinto, who was responsible for conducting the tests in Burkina Faso. Otherwise, the introduction of the vaccine could be significantly delayed.
A vaccine against the tropical disease has been researched for many decades. One stumbling block is that the malaria parasite is a much more complex organism than a virus and also has a complicated life cycle with several different stages, offering a wide range of potential vaccine targets, says Katie Ewer, who is involved in the new study was. The current vaccine starts at the point where the parasite has just entered the human body and the number of these protozoa is not yet that large.
Like RTS,S, the vaccine contains a protein from the parasite and a carrier protein derived from the hepatitis B virus. However, R21 uses a lower amount of the hepatitis protein, which should allow the human immune system to focus more on producing antibodies against malaria. In addition, according to the team, a more potent enhancer was used.