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CDC James Gathany
The groundwork for the miraculously rapid development of COVID-19 vaccines actually began a few decades ago with basic research on molecular subunit vaccine technologies. In April 2021, the same researchers from the University of Oxford who developed the Oxford/AstraZeneca vaccine announced extraordinary findings with their experimental malaria vaccine R21/MM, which also uses subunit technology.
While R21/MM may substantially reduce child mortality numbers in Sub-Saharan Africa, the new vaccine may have less direct relevance to the Asia Pacific’s malaria problem for several reasons highlighted in a post by Professor Kevin Baird.
The ideal vaccine for Asia Pacific would need to offer protection not just from illness, but infection, so the vaccinated could not be carriers at all. This ‘sterilising immunity’ is a tall order but scientists are in hot pursuit with another technology — live attenuated sporozoite vaccines — which may provide that protection. This kind of vaccination also proved effective across different species of parasites in laboratory animal models for malaria.
A malaria vaccine ideally suited to the Asia Pacific would offer sterilising immunity against infection by any of the five species of parasites in the region that naturally infect people. Health officials could target the many pockets and scattered zones of active malaria transmission in Asia for vaccination. Interrupting the cycle of malaria transmission for only a few months could eliminate it, making vaccination a brief intervention rather than a lifetime enterprise — as it is with almost all other vaccines.
Another type of vaccine — which prevents humans from infecting mosquitoes — is currently in development. These transmission-blocking vaccines would also help rid Asia of its malaria problem.