Inclusion Criteria

- INCLUSION CRITERIA:

1. Males or females between 18 and 45 years, inclusive.

2. Good general health as determined by means of the screening procedure.

3. Available for the duration of the trial (48 weeks).

4. Willingness to participate in the study as evidenced by signing the informed
consent document.

5. For female subjects: Negative pregnancy tests at Screening and Day 0, in
conjunction with a history indicating a low probability of pregnancy in the
opinion of the physician. Sexually active females of childbearing potential
will be required to be correctly using an efficacious method of contraception
for at least 1 month before randomization and during the on-study phase to Month
7. Female subjects unable to become pregnant must have this documented (e.g.
tubal ligation, hysterectomy, or postmenopausal [at least one year since last
menstrual period]).

EXCLUSION CRITERIA:

1. History of malaria, residence for more than 1 month in a malaria endemic area (as
determined by interview), or plans to visit a malaria endemic area during the study
period.

2. For female subjects: Positive pregnancy test at screening or Day 0, as well as those
currently lactating and breast feeding.

3. Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic,
rheumatologic, chronic infectious or renal disease by history, physical examination,
and/or laboratory studies including urinalysis.

4. Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator
affects the ability of the volunteer to understand and cooperate with the study
protocol.

5. Laboratory evidence of liver disease (alanine aminotransferase [ALT] greater than
1.25 times the upper limit of normal of the testing laboratory).

6. Laboratory evidence of renal disease (serum creatinine greater than the upper limit
of normal of the testing laboratory, or more than trace protein or blood on urine
dipstick testing confirmed by repeat testing of clean-catch, midstream sample).
(More than trace blood on urine dipstick will not exclude a female who is actively
menstruating).

7. Laboratory evidence of hematologic disease (absolute leukocyte count less than
3000/mm(3) or greater than 11,500/mm(3); hemoglobin less than 0.9 times the lower
limit of normal of the testing laboratory, by gender; absolute granulocyte count less
than 1300/mm(3); absolute lymphocyte count less than 1000/mm(3); or platelet count
less than 11,000/mm(3)).

8. Other condition that, in the opinion of the investigator, would jeopardize the safety
or rights of a volunteer participating in the trial or would render the subject
unable to comply with the protocol.

9. Participation in another investigational vaccine or drug trial within 30 days of
starting this study, or while this study is ongoing.

10. Volunteer has had medical, occupational, or family problems as a result of alcohol or
illicit drug use during the past 12 months.

11. History of a severe allergic reaction or anaphylaxis.

12. Severe asthma. This will be defined as:

- Asthma that is unstable or required emergent care, urgent care, hospitalization
or intubation during the past two years or that requires the use of oral or
parenteral corticosteroids.

- Clinically significant reactive airway disease that does not respond to
bronchodilators.

13. Positive ELISA for anti-HCV.

14. Positive hepatitis B surface antigen (HBsAg) by ELISA.

15. Positive ELISA for anti-HIV.

16. Use of systemic corticosteroids (excluding topical or nasal) or immunosuppressive
drugs within 30 days of starting this study.

17. Receipt of a live vaccine within past 4 weeks or non-live vaccine within past 2 weeks
prior to entry into the study.

18. History of a surgical splenectomy.

19. Receipt of blood products within the past 6 months.

20. Previous receipt of an investigational malaria vaccine.

21. History of a known allergy to nickel.