A new malaria vaccine has demonstrated an unprecedented 77 per cent efficacy in early trials on young children, and it could be a major breakthrough against the disease. In the process, the vaccine has become the first to reach the target of at least 75 per cent efficacy set by the World Health Organization (WHO). The researchers conducted a double-blind, randomised, controlled trial of R21, a low-dose circumsporozoite protein-based vaccine, on 450 children between the ages of five and 17 months in Burkina Faso, a country in West Africa. The vaccine was found to be safe, and showed a high-level efficacy over the period of a year.
The researchers had divided the children into three groups and administered either a low dosage or a high of the new vaccine R21 or a rabies vaccine. Three doses, at an interval of four weeks, were administered to each participant before the malaria season and the fourth dose a year later. The team then observed the children over the year and evaluated the vaccine's safety and efficacy. The results were been published in the medical journal Lancet in pre-print form, which means the paper is yet to be peer-reviewed.
The vaccine demonstrated efficacy of 77 percent against malaria among the group-administered high dosage of R21 and 71 per cent among children who were given low dosage shots. Not just that, the efficacy remained as high as 77 percent in the high-dose group.
“Participants vaccinated with R21/ MM showed high titres of malaria-specific anti-NANP antibodies 28 days after the third vaccination, which were almost doubled with the higher adjuvant dose," the findings in the paper read. Even though titres, the concentration of specific antibodies, waned, they were boosted to levels similar to the peak following the primary series of vaccinations after a fourth dose administered a year later, it added. The researchers said that R21 appeared safe and very immunogenic in African children, and demonstrated promising high-level efficacy.
To date, RTS, S/AS01 is considered to be the most effective malaria vaccine, with an efficacy rate of 55.8 per cent among African children. According to the WHO, children under the age of five are the most vulnerable to malaria. They, in fact, comprised nearly 67 percent of deaths due to malaria globally.
The WHO's 2020 report on Malaria stated that 4 lakh people died of the disease. An estimated two-thirds of the deaths were among children under the age of five. The 2019 report shed light on the magnitude of the crisis and estimated that there were 2.29 crore cases of malaria across the world.
The disease has taken a huge toll on countries in the African region, which accounted for an extremely high proportion of the global malaria burden. In 2019, the region had 94 percent of global malaria cases and deaths.