Vaccines clinical trials

Experimental Vaccine for Plasmodium Falciparum Malaria

This study will evaluate the safety of two experimental malaria vaccines in healthy volunteers and examine their immune response to them. Safety will be assessed by comparing vaccine side effects in groups of volunteers who receive increasing doses of the same vaccine (dose-escalating study). Immune response will be evaluated by comparing the levels of antibody production with each dose. (Antibodies are infection-fighting proteins produced by the immune system.) The two vaccines in this study contain different types of a malaria protein called MSP1: one type is MSP142FVO and the other is MSP1423D7. Malaria parasites are spread from person to person by mosquitoes. There are four types of malaria parasites. The vaccine tested in this study is designed to work against Plasmodium falciparum, the parasite responsible for most deaths in children due to malaria in sub-Saharan Africa. The vaccine stimulates the body to produce antibodies that prevent P. falciparum from entering the person's red blood cells. Healthy normal volunteers between 18 and 50 years of age may be eligible for this 12-month study, conducted at Quintiles Phase 1 Services in Lenexa, Kansas. Candidates are screened with a medical history, physical examination, and blood and urine tests. Participants receive three doses of the vaccine-on the first day of the study (day 0), at 1 month (day 28), and at 6 months (day 180) -through injection into an arm muscle. The first group of subjects receives 5 micrograms of vaccine, the second group receives 20 micrograms, and the third group receives 80 micrograms. All participants are observed in the clinic for 30 minutes after each immunization for immediate reactions to the vaccine and keep a record of their temperature and of any reactions and side effects they experience for 6 days after the vaccination. At various intervals throughout the study, participants undergo a brief physical examination and blood tests. Women of childbearing potential have a urine pregnancy test on the day of each injection.