ChAd63 AMA1 demonstrated a good reactogenicity profile, similar to that seen consistently with the same doses of ChAd63 vectored vaccines encoding the pre-erythrocytic malaria antigen ME-TRAP (O'Hara et al., J Infect Dis 2011 in press) and the blood-stage antigen MSP1 [30], supporting the growing body of evidence that this simian adenovirus vector is safe for clinical use. The gene discussed is ATAD1; the disease is malaria.