This randomized, double-blind, placebo-controlled, Phase 1 trial will enroll up to 22 malaria-naïve, adult participants to test safety, tolerability, immunogenicity, and efficacy of the genetically attenuated Plasmodium falciparum sporozoite vaccine (PfSPZ-LARC2) Vaccine. PfSPZ-LARC2 Vaccine is a late-arresting, replication-competent whole Plasmodium falciparum sporozoite product. We hypothesize that the PfSPZ-LARC2 Vaccine will be safe from breakthrough infection by virtue of deletion of two key parasite genes Mei2 and LINUP and may be more immunogenic and protective than previously tested early arresting sporozoite vaccines. The primary objective is to assess the tolerability and safety of administration of PfSPZ-LARC2 Vaccine, with special attention to the adequacy of attenuation.
Who can participate
Age range
18 Years – 45 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Provides written informed consent prior to the initiation of any study procedures.
. Able to understand and agrees to adhere to all planned study procedures and be available for all study visits.
. Male or non-pregnant female, 18 to 45 years of age (inclusive) at time of enrollment.
. BMI 18.0-35.0 kg/m\^2 at screening.
. Females of childbearing potential\* must agree to use or have practiced true abstinence\*\* or use at least one acceptable primary form of contraception\*\*\*,\*\*\*\*,\*\*\*\*\* Note: These criteria are applicable to females in a heterosexual relationship and child-bearing potential (i.e., the criteria do not apply to participants in a same sex relationship).
. Females of childbearing potential must have a negative urine or serum pregnancy test within 24 hours prior to enrollment.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Occurrence of Grade 3 laboratory toxicities related to vaccination
Timeframe: Through 14 days after the last vaccination
2
Occurrence of serious adverse events (SAEs) considered related to vaccination
Timeframe: Through 180 days post-CHMI
3
Occurrence of solicited local adverse events (AEs) related to the vaccine
Timeframe: Through 6 days after each vaccination
4
Occurrence of solicited systemic adverse events (AEs) related to the vaccine
Timeframe: Through 6 days after each vaccination
5
Occurrence of unsolicited adverse events (AEs) considered related to vaccination
Timeframe: Through 28 days after the last vaccination
6
Proportion of participants with breakthrough blood-stage infection
Timeframe: Through 28 days after last vaccination
7
Solicited systemic adverse event (AE) related to the breakthrough infections
Trial details
NCT IDNCT06735209
SponsorNational Institute of Allergy and Infectious Diseases (NIAID)
. Males of childbearing potential: use condoms with a female partner of childbearing potential from their enrollment visit (Visit 1), to 60 days after last vaccination or 28 days post-Controlled Human Malaria Infection (CHMI), whichever is later.\*,\*\*
. Male participants agree to refrain from sperm donation from the time of first vaccination until 60 days after the last vaccination or until 28 days post-CHMI, whichever is later.
Exclusion criteria
. Unable to provide informed consent including inability to pass the test of understanding.
. Receipt of a malaria vaccine in a prior clinical trial.
. History of malaria infection within 2 years prior to study participation.
. History of a splenectomy or sickle cell disease.
. History of a non-febrile seizures or complex febrile seizures.
. Current use of systemic immunosuppressant/immunomodulatory pharmacotherapy.
. Receipt of a live vaccine within 4 weeks of first vaccination or of 3 or more non-live vaccines within 2 weeks of first vaccination.
. Receipt of a live vaccine within 4 weeks of CHMI for infectivity controls or of 3 or more non-live vaccines within 2 weeks of CHMI for infectivity controls.