PfSPZ-CVac
PfSPZ-CVac
is a Malaria vaccine candidate composed of attenuated sporozoites
Under development by Sanaria Inc., with support of the i-PfSPZ-consortium
PfSPZ-CVac
The PfSPZ Vaccine of Sanaria will be the first PfSPZ-based vaccine licensed in the EU and US, and is intended to be used initially to prevent malaria in travelers, and then to prevent malaria in individuals in malaria endemic regions, especially in children in areas of Africa with seasonal transmission, and eventually regionally to halt transmission. Sanaria’s second generation Plasmodium falciparum (Pf) sporozoite (SPZ) vaccine, Sanaria PfSPZ-CVac (Chemoprophylaxis Vaccine), addresses objectives of increased potency and decreased costs of goods (COG).
PfSPZ-CVac is a chemoprophylaxis-attenuated (weakened) whole organism vaccine. This means that, rather than attenuating with radiation as does PfSPZ Vaccine, an injectable form of malaria is given at the same time as an anti-malarial drug. This allows the parasite to elicit an immunological response in the body against malaria, but the chemoprophylactic drug kills the parasite before the individual starts getting sick. PfSPZ-CVac requires a small fraction of the dose to protect the individual, and it too is safe, well tolerated and provides a high level of protection from malaria.
The hypothesis underlying PfSPZ-CVac, now well supported with clinical data, is that if the parasite is allowed to replicate in the liver of the host where it amplifies 20,000 to 50,000-fold and produces 3,000 new proteins before entering the blood, it will be more preventive at a much lower dose. This is because the antigen load presented to the immune system and the potency per PfSPZ parasite for inducing protective immunity increases massively. This principle underlies successful live attenuated vaccines for many diseases.
In the first iteration of PfSPZ-CVac, Sanaria co-administered infectious PfSPZ (PfSPZ Challenge) with the partner drug chloroquine. PfSPZ-CVac provided 100% VE against controlled human malaria infection (CHMI) at 10 weeks after vaccination using <10% the amount of PfSPZ compared to PfSPZ Vaccine.
In a third approach, in collaboration with Seattle Children’s Research Institute, recombinant technology is being used to create a genetically attenuated mutant parasite that is replication competent but arrests late in liver development (Sanaria PfSPZ-LARC). Preliminary results are promising.
Sanaria Inc. is a Biotech company, located in Maryland, USA, developing vaccines against the parasite Plasmodium falciparum (Pf), one of the deadliest form of malaria parasites. The company has been working towards the goal of eliminating malaria in endemic regions since its foundation in 2003. Sanaria is the only vaccine company in the world dedicated solely to the development of malaria vaccines. It is part of several research collaborations in Europe, Asia and the USA.