First Malaria Vaccine RTS, S: New Hope for Patients
Recently, WHO launch a pilot vaccine program for malaria in Malawi, with a breakthrough in malaria vaccine development.
WHO says ” RTS,S is the first, and to date, the only vaccine that has demonstrated it can significantly reduce malaria, and life-threatening severe malaria, in young African children. Beginning in 2019, 3 sub-Saharan African countries – Ghana, Kenya, and Malawi – are leading the introduction of the vaccine in selected areas of moderate-to-high malaria transmission as part of a large-scale pilot programme coordinated”.
Malaria is one of the world’s worst infectious diseases. To put it into perspective, data from the WHO shows that in the year 2018, more than 400,000 people lost their lives to the disease globally. More disturbing is the fact that this is one of those diseases that can cause mortality quite fast. And directly. So in most cases, it is not a question of people dying from ‘malaria-related complications’. Rather, what we see in most cases are people dying directly from malaria infection. That is a very important observation.
Malaria itself is caused by plasmodium group organisms, which are transmitted through mosquitos.
From as early as the year 2000, there have been ongoing efforts to develop a malaria vaccine. Before that, most of the available help (for people seeking to avert malaria infections) was in the form of malaria prophylaxis medications. Those included the likes of Mefloquine, Atovaquone, Doxycycline, Chloroquine, and Hydroxychloroquine. But these were not always effective at preventing malaria infections. Neither were those medications efficient to administer. That is what created the need for malaria vaccine development.
Who is involved in malaria vaccine development?
Some of the entities involved in malaria vaccine development include GlaxoSmithKline (the pharmaceutical giant) in coordination with the PATH Malaria Vaccine Initiative. In this work, the two bodies got a helping hand from the Bill and Melinda Gates Foundation. The result of that effort was the RTS, S malaria vaccine — otherwise known as Mosquirix. It was first malaria to get global phase III approval – but with very many conditionalities. It is a good but relatively low efficacy malaria vaccine, currently in use/broader population testing in some quarters.
Another agency involved in malaria vaccine development is the Serum Institute of India. This work, it has been working hand in hand with the Kenya Medical Research Institute (KEMRI) and Novanax. The result of that effort has been the Matrix-M vaccine, which as of early 2021 was undergoing [but not yet through with] phase III trials. This so far seems to be the most promising malaria vaccine, in terms of efficacy.
Other entities that are involved in malaria vaccine development include Sanaria (for the PfSPZ malaria vaccine) and Pattaroyo et al (for the SPf66 malaria vaccine).
Malarial vaccine trial phases
Like all other vaccines, malaria vaccines are expected to undergo four phases (phase I to phase IV) of trial, before being given full approval. What is being studied in all these phases is primarily the efficacy and the safety of the vaccine. Phase I and phase II trials tend to involve relatively few volunteers. Phase III involves many more subjects. By the time it gets to phase IV, the vaccine has undergone licensing and is being marketed/used broadly – with more data being collected about its efficacy and safety. So far, the only malaria vaccine that seems to have fully undergone the first three (phase I to III) of these phases is the RTS,S vaccine (brand name Mosquirix). It is, as of May 2021, the only WHO-approved malaria vaccine. Yet to the extent that it hasn’t yet fully gone through phase IV trial, it isn’t fully available in the open market. But it is being used in the general pediatric populations in certain areas of nations like Malawi, Ghana, and Kenya.
Matrix-M has shown better efficacy than RTS,S malaria vaccine: though it is yet to get full approval. It is yet to advance past phase III in the approval process – which Mosquirix/RTS,S has gone through. Others are in various stages of the investigation, with the likes of PfSPZ and saRNA malaria vaccines.
Availability in the market
As mentioned earlier, the only vaccine that (as of May 2021) has WHO approval is the RTS,S vaccine. It is available under the name of Mosquirix, though it is not yet fully available in the market. The challenges identified with regard to Mosquirix/RTS,S vaccine include relatively low efficacy and the fact that it has to be administered through four injections. Frankly speaking, the Matrix-M malaria vaccine seems to offer better protection/higher efficacy, with more user-friendly administration. The problem with it is in the fact that it hasn’t yet gotten full approval. And this means that people seeking protection through it have to wait a while longer.
Thus, the only Malaria vaccine that is in widespread usage is Glaxosmithkline’s Mosquirix (officially known as RTS, S). But even where it is being used – in certain parts of the African nations of Malawi, Ghana, and Kenya – it is part of government vaccination programs. Thus, for the moment, it is not the sort of thing you can venture into a drug store and order for.
One can, however, realistically hope that in the next decade or so, we will see malaria vaccines that are available in the open market. After all, the likes of Mosquirix and Matrix-X have already demonstrated acceptable efficacy. All that is remaining are a few safety appraisals before the said vaccines can be made available to the broader market.
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