Safety, immunogencity, and efficacy of PfSPZ LARC2 malaria vaccine in malaria-exposed adults and children

Malaria cases and deaths have been unchanged for the past 6 years despite $3-4 B annual investment in control measures. A highly efficacious vaccine would save lives by providing durable protection against infection and support global eradication efforts by blocking transmission. Current malaria control strategies including insecticide-impregnated bed nets, indoor residual spraying and antimalarial drugs have reduced malaria rates in many countries, but malaria still causes 247 million cases and 619,000 deaths annually. In late 2022, the WHO published its Preferred Product Characteristics for Malaria Vaccines. Strategic Goal 1 was, “Malaria vaccines that prevent human blood-stage infection at the individual level in >90% of recipients.” Successful development and deployment of a highly efficacious malaria vaccine with these characteristics would both reduce malaria morbidity and mortality and accelerate malaria eradication efforts. The only malaria vaccines that have ever reached this level of efficacy have been Plasmodium falciparum (Pf) sporozoite (SPZ) vaccines, including PfSPZ Vaccine and PfSPZ-CVac. To achieve the tolerability and safety of PfSPZ Vaccine and the VE and potency of PfSPZ-CVac, a 3rd generation vaccine has been created and manufactured in compliance with cGMPs. PfSPZ- LARC2 is a late arresting replication competent (LARC) parasite, attenuated by deletion of two genes. PfSPZ- LARC2 Vaccine will undergo clinical assessment of tolerability, safety, and vaccine efficacy (VE) in 2023 in the US and Germany. The next steps for clinical development of PfSPZ-LARC2 Vaccine include safety and immunogenicity testing in malaria-experienced adults with subsequent age de-escalation and additional safety, immunogenicity, and VE testing in children living in a highly endemic area. Planning activities that will be supported by the current proposal include development of the clinical trial protocol, informed consent form, manual of procedures, case report forms, data management plan, data and safety monitoring plan, protocol-specific training materials and plans for study staff, trial budget, study product management plan, and regulatory submission plan.

NIH Project details

Vaccines (Immune Correlates)

Jun 2024 — May 2025

$250,796

Burkina Faso