Malaria

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blocking the parasite at different levels of its life cycle

 

According to the WHO, there were an estimated 207 million cases of malaria in 2012 and an estimated 627 000 deaths of which 482 000 children under five years of age. 90% of all malaria deaths occur in sub-Saharan Africa. That is 1300 children every day, or one child almost every minute.
If not treated, malaria can quickly become life-threatening. In many parts of the world, the parasites have developed resistance to a number of malaria drugs. Malaria being an extremely climate-sensitive disease, a potential risk exists that Global Warming leads Malaria towards areas in higher latitudes.1

Mymetics' malaria Vaccine Approach

The parasite has two main stages of development, implying that the surface of the parasite (sporozoites or merozoites) are constantly changing. Accordingly, the ideal vaccine should target different proteins from the various stages to improve the chance of obtaining protection or reducing the symptoms related mostly to the red blood cell infection.

The first malaria vaccine candidate is using the influenza virosome as the carrier and adjuvant with the incorporation of several antigens that target the two forms of the parasite and is thereby one of the few vaccine developed with this approach.

The second malaria vaccine candidate is a transmission blocking vaccine which also uses the Mymetics virosome technology by incorporating two transmission blocking antigens from the Laboratory of Malaria Immunology and Vaccinology (LMIV) of the NIAID.

The transmission-blocking vaccine candidate seek to interrupt the life cycle of the parasite by inducing antibodies that prevent the parasite from maturing in the mosquito after it takes a blood meal from a vaccinated person. A successful transmission-blocking vaccine would be expected to reduce deaths and illness related to malaria in at-risk communities.

Target population and market size

Both these vaccine candidates are primarily targeted to the overall population in sub-Saharan Africa and as a traveller vaccine. The market size for a malaria vaccine is estimated at USD 400 to USD 600 million.

A vaccine reducing malaria episodes

The first vaccine candidate completed a Phase 1b clinical trial in Tanzania in close collaboration with the Swiss Tropical and Public Health Institute. The clinical trial study confirmed that the company's virosome-based vaccine was well tolerated and safe for adults and children as young as 5 years of age. The vaccine induced specific antibodies against the key AMA-1 and CSP-1 Malaria antigens in semi-immune subjects, lasting up to 12 months for the CSP-1. Overall the vaccine reduced the malaria episodes by 50%. (link to publication)

Next steps

The second malaria vaccine candidate, the transmission blocking malaria vaccine, is in its preclinical stage and fully funded by the PATH Malaria Vaccine Initiative (PATH MVI) and in collaboration with LMIV. This collaboration and funding was announced in November 2014 and first results were announced in April 2016 (see release).

The first initial results from the study showed that the virosome vaccine candidates, at the highest dose tested, generate high antibody titers against the required antigens and they were able to significantly reduce (97-100%) the transmission of the Plasmodium falciparum parasite.

Mymetics is currently evaluating funding opportunities for further development of the vaccine candidates.


1 Reiter P. Global warming and malaria: knowing the horse before hitching the cart; Malaria Journal ( December 11, 2008).

Publications: Virosome-Formulated Plasmodium falciparum AMA-1 & CSP Derived Peptides as Malaria Vaccine: Randomized Phase 1b Trial in Semi-Immune Adults & Children