# A Pilot Study to Evaluate Plasmodium falciparum Liver-Stage Challenge in Prime-and-Trap Vaccinated Rhesus Monkeys

> **NIH NIH R03** · UNIVERSITY OF WASHINGTON · 2020 · $88,250

## Abstract

ABSTRACT
The world needs a highly effective pre-erythrocytic vaccine for malaria prevention. Immunocompetent animal
models are needed to test candidate vaccines targeting the most lethal species: Plasmodium falciparum (Pf).
However, Pf does not infect mice and does not cause blood-stage infections in the common rhesus non-human
primate (NHP) model. Although rhesus do not support blood stage infections, our preliminary data shows that
parasites actively proliferate in the preceding liver stage, making it possible to monitor liver burden in naïve vs.
immunized animals by RT-PCR as an efficacy endpoint. This sort of endpoint is well accepted in rodent
models, but has not been widely used in NHP studies because the growth of Pf in rhesus livers was
unappreciated until now. We propose to establish this model and compare the liver burden in immunologically-
naïve NHP compared to NHP vaccinated in a pilot study using our ‘prime-and-trap’ approach that generates
protective liver resident memory CD8+ T cells. This model is enabled by high quality diagnostics, and our lab is
considered a reference center for molecular detection of malaria parasites – therefore we are well suited to
evaluate the proposed model. The study will (a) provide additional data on use of Pf/rhesus as a useful NHP
model for pre-erythrocytic malaria vaccines and (b) provide translational data on our prime-and-trap vaccine to
advance this promising vaccine approach and accelerate funding for further translational studies.

## Key facts

- **NIH application ID:** 9842667
- **Project number:** 5R03AI144143-02
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Sean C Murphy
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $88,250
- **Award type:** 5
- **Project period:** 2019-01-01 → 2020-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9842667

## Citation

> US National Institutes of Health, RePORTER application 9842667, A Pilot Study to Evaluate Plasmodium falciparum Liver-Stage Challenge in Prime-and-Trap Vaccinated Rhesus Monkeys (5R03AI144143-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9842667. Licensed CC0.

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