Long-term safety and efficacy of the RTS,S/AS02A malaria vaccine in Mozambican children

Jahit Sacarlal, Pedro Aide, John J. Aponte, Montse Renom, Amanda Leach, Inácio Mandomando, Marc Lievens, Quique Bassat, Sarah Lafuente, Eusébio Macete, Johan Vekemans, Caterina Guinovart, Betuel Sigaúuque, Marla Sillman, Jessica Milman, Marie Claude Dubois, Marie Ange Demoitié, Joelle Thonnard, Clara Menéndez, W. Ripley BallouJoe Cohen, Pedro L. Alonso

Research output: Contribution to journalArticlepeer-review


Background. We previously reported that the RTS,S/AS02A vaccine had an acceptable safety profile, was immunogenic, and demonstrated efficacy against Plasmodium falciparum malaria disease for 21 months. Methods. We conducted a randomized, controlled, phase 2b trial of RTS,S/AS02A in 2022 Mozambican children aged 1-4 years. We now report safety results for all randomized subjects and vaccine efficacy (VE) findings for children in the Manhiça area over the 45-month surveillance period. Results. During the surveillance period, the VE(2.5-45) (VE over months 2.5-45 of surveillance) against a first or only episode of clinical malaria disease was 30.5% (95% confidence interval [CI], 18.9%-40.4%; P< .001), and the VE (2.5-45) against all episodes was 25.6% (95% CI, 11.9%-37.1%; P< .001 ). When the same period was considered, the VE(2.5-45) for subjects protected against severe malaria was 38.3% (95% CI, 3.4%-61.3%; P = .045). At study month 45, the prevalence of P falciparum was 34% lower in the RTS,S/AS02A group than in the control group (66 [12.2%] of 541 patients vs 101 [18.5%] of 547 patients) (P = .004). Conclusion. These results show evidence that RTS,S/AS02A maintained protection during the 45-month surveillance period, and they highlight the feasibility of developing an effective vaccine against malaria. In combination with other malaria-control measures, such a vaccine could greatly contribute to reducing the intolerable global burden of this disease.

Original languageEnglish
Pages (from-to)329-336
Number of pages8
JournalJournal of Infectious Diseases
Issue number3
Publication statusPublished - 2009


Dive into the research topics of 'Long-term safety and efficacy of the RTS,S/AS02A malaria vaccine in Mozambican children'. Together they form a unique fingerprint.

Cite this