|
|
||||||||

We conducted a phase 1 trial of candidate malaria vaccine RTS,S/AS02A in western Kenya to determine its safety and immunogenicity in healthy adults in an area hyperendemic for malaria. Twenty adults were enrolled and received RTS,S/AS02A (50 µg of RTS,S in 0.5 mL of AS02A) by intramuscular injection on a 0-, 28-, and 178-day schedule. All 60 scheduled immunizations were given, and 18 of 20 volunteers completed the last study visit on day 210. The vaccine was safe and well-tolerated. There were no vaccine-related severe adverse events. The most common solicited adverse events associated with immunization were injection site pain and headache. The geometric mean concentration of antibodies to circumsporozoite protein was 1.9 µg/mL at baseline and it increased 24 weeks after each dose to 16, 17.8, and 36.6 µg/mL, respectively. These safety and immunogenicity data from adults in hyperendemic Kenya are comparable to data reported earlier from two trials in west African adults in hypo-endemic and meso-endemic areas of The Gambia. We conclude that in this small study, RTS,S/AS02A is safe and similarly immunogenic in malaria-exposed African adults of different ethnicity in different transmission settings.
Received January 26, 2006. Accepted for publication February 25, 2006.
Acknowledgments: We thank Senior Technician Ramadan Mtalib and Field Team Manager Samuel Oduor for assistance. This work was presented in part at the Second Multilateral Initiative on Malaria Conference in Durban, South Africa, March 1519, 1999 and at the 49th Annual Meeting of the American Society of Tropical Medicine and Hygiene, Houston, Texas, October 29November 2, 2000.
Financial support: This study was supported by the United States Army Medical Research and Materiel Command (Fort Detrick, Frederick, MD) and GlaxoSmithKline Biologicals (Rixensart, Belgium).
Disclaimer: The views expressed by the authors are private and not to be construed as official opinions of the Departments of the Army or of Defense.
Disclosure: Joe D. Cohen, Laurence Vigneron, and Gerald Voss, and W. Ripley Ballou are employees of GlaxoSmithKline Biologicals, the manufacturer of the RTS,S/AS02A vaccine. Joe D. Cohen, Gerald Voss, and W. Ripley Ballou hold shares of stock in GlaxoSmithKline. Joe D. Cohen is listed as an inventor on patented malaria vaccines based on RTS,S/AS02A; however, he is not a holder of such patents. None of the other authors have declared conflicts of interest.
* Address correspondence to D. Gray Heppner Jr., or José A. Stoute, Malaria Vaccine Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910. E-mail: donald.heppner{at}na.amedd.army.mil
Authors addresses: José A. Stoute, D. Gray Heppner Jr., and Kent E. Kester, Malaria Vaccine Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910. Carl J. Mason, U.S. Army Medical Component, Armed Forces Research Institute of Medical Sciences, APO AP 96546. Joram Siangla, U.S. Army Medical Research Unit, Unit 64109, APO AE 09831-4109. Laurence Vigneron, Gerald Voss, Joe D. Cohen, and W. Ripley Ballou, GlaxoSmithKline Biologicals, Rue de lInstitut 89, B-1330 Rixensart, Belgium. Michael J. Walter, Irwin Army Community Hospital, Fort Riley, KS 66442-5037. Nadia Tornieporth, North America Sanofi Pasteur, Discovery Drive, Swiftwater, PA 18370.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |