After decades of work, the only approved malaria vaccine, Mosquirix, made by British drugmaker GSK, was recently endorsed by the World Health Organization (WHO).
Oxford’s vaccine, called R21/Matrix-M, is likely more effective than Mosquirix in preventing the disease that kills around 600,000 people a year despite the estimated $3 billion spent each year on insecticides, mosquito nets and antimalarial drugs, a said Oxford scientist Adrian Hill.
GSK also has a manufacturing advantage, he added, citing an agreement with the Serum Institute of India to produce 200 million doses a year, starting in 2023.
By contrast, GSK has pledged to produce up to 15 million doses of Mosquirix each year until 2028, well below the approximately 100 million doses per year of the four-dose vaccine that the WHO estimates is needed over the long term to cover about 25 million children.
GSK said it cannot produce enough Mosquirix to meet the vast demand without more funds from international donors.
On Wednesday, data from a mid-term study of more than 400 young children who received a fourth dose of the Oxford vaccine after the primary three-dose regimen were published https://www.thelancet.com/journals/laninf/article /PIIS1473-3099(22)00442-X/fulltext in the Lancet journal.
Vaccine efficacy was 80% in the group that received a higher dose of the adjuvant component of the vaccine, which boosts the immune system, and 70% in the group that received a lower dose of adjuvant, 12 months later. the fourth dose. The doses were administered before the peak of the malaria season in Burkina Faso.
MOSQUIRIX
The complex structure and life cycle of the malaria parasite has long hampered vaccine development efforts. GSK’s Mosquirix was designed in the 1980s and paved the way for the Oxford team to create a more potent vaccine, Hill said.
However, it is difficult to draw direct comparisons between the two vaccines, as data from a larger, ongoing phase III trial testing the Oxford vaccine and involving 4,800 participants are not yet available. .
Meanwhile, data from a late phase trial published last year showed that if Mosquirix was given before the peak of the malaria season in high transmission areas, it was nearly 63% effective https:// www.nejm.org/doi/full/10.1056/NEJMoa2026330 against clinical malaria.
Comparisons between the two vaccines at this stage should be tentative, as they have not yet been compared head-to-head in the same trial, said David Conway of the London School of Hygiene & Tropical Medicine.
However, these phase II data suggest that the Oxford vaccine is an improvement over Mosquirix, improving efficacy and retention of immunity, said Alister Craig of the Liverpool School of Tropical Medicine.
Oxford plans to submit Phase III data to the WHO imminently, hoping for key approval next year.