Moderate efficacy malaria vaccines as part of comprehensive malaria control and elimination

Transcription

1 Moderate efficacy malaria vaccines as part of comprehensive malaria control and elimination

2 Progress and Limitation of Existing Vector Control Tools Draper & Smith 1960 TRSTMH 54: 342

3 Cannot afford to stop

4 Global malaria vaccine pipeline TRANSLATIONAL PROJECTS VACCINE CANDIDATES Phase 1a Phase 2a Phase 1b Phase 2b Phase 3 ChAd63/MVA ME-TRAP + Matrix M Ad35.CS/ RTS,S-AS01 M3V.Ad.PfCA Ad35.CS ChAd63/MVA ME-TRAP RTS,S-AS01 Polyepitope DNA EP 1300 PfCelTOS FMP012 Ad35.CS/ Ad26.CS ChAd63/ MVA (CS, TRAP, AMA) M3V.D/ Ad.PfCA ChAd63/MVA MSP 1 EBA 175.R2 SE36 GMZ2 MSP3 [ ] CSVAC ChAd63.AMA1/ MVA.AMA1 PfSPZ ChAd63.AMA/ MVA.AMA1 +Al/CPG7909 FMP2.1-AS01B (AMA1 3D7) SR11.1 ChAd63/MVA PvDBP Pfs25-EPA Pfs25-VLP P. falciparum vaccines: P. vivax vaccines: Pre erythrocytic Blood stage Transmission blocking Pre erythrocytic Blood stage Transmission blocking Data source:

5 RTSS Phase 3 Trial in Africa Randomized, controlled, doubleblind trial designed to evaluate vaccine efficacy, safety, reactogenicity, and immunogenicity in children up to 32 months after the administration of the first dose of vaccine. Two age categories: Children 6-12 weeks of age: 7100 Children 5-17 months of age: centers in 7 African countries Trial implemented with optimized vector control and malaria treatment The co-primary endpoints of the trial are: vaccine efficacy against clinical malaria after 12 months of follow-up in each age category.

6 e Efficacy over 18 months follow-up [ATP] and Malaria nce in Controls VE 1 OVERALL Kilifi Korogwe Bagamoyo Manhiça Lambarene Lilongwe Agogo Kombewa Kintampo Nanoro Siaya 1.8 episodes/yr VE 1 OVERALL Kilifi Korogwe Bagamoyo Manhiça Lambarene Lilongwe Agogo Kombewa Kintampo Nanoro Siaya 1.4 episodes/yr

7 t of RTS,S/AS01 on clinical malaria over 18 months of follow- VE 1 OVERALL Kilifi Korogwe Bagamoyo Manhiça Lambarene Lilongwe Agogo Kombewa Kintampo Nanoro Siaya Number of cases averted (per 1000 children vaccinated) cases averted (47 to 2356) 2 VE 1 OVERALL Kilifi Korogwe Bagamoyo Manhiça Lambarene, Lilongwe Agogo Kombewa Kintampo Nanoro Siaya 444 cases averted (-12 to 1429) 2

8 ainst severe malaria, malaria hospitalization ll-cause hospitalization over 18 Months VE* in children [95%CI] VE* in infants [95%CI] ere malaria 36% [15 51] 15% [0 39] ria hospitalization 42% [29 52] 17% [-7 36] ause italization 19% [9 28] 6% [-7 17] lculated as 1 Risk Ratio (Unadjusted) r 18 months per 1000 vaccinees; RTS,S/AS01 rted 21 [range:-4-44] cases and 8 [range:-14-33] es of severe malaria in children and infants pectively. se fatality rate for malaria and all-cause rtality was low and VE was not demonstrated

9 incidence of clinical and severe malaria (primary case ns) by 6-month periods (per-protocol population) n 5-17 months of age at enrollment - clinical malaria B. Infants 6-12 weeks of age at enrollment - clinical malaria n 5-17 months of age at enrollment - severe malaria D. Infants 6-12 weeks of age at enrollment - severe malaria

10 O recommends Large scale Pilot lementation of RTSS in Africa recommends the pilot implementations of the 4-dose dule of the RTS,S/AS01 vaccine in 3 5 distinct emiological settings in sub-saharan Africa, at ational level, covering moderate-to-high transmission ngs, with three doses administered to children een 5 and 9 months of age, followed by a fourth dose 8 months later. s to involve sufficiently large populations also to ss, asibility of providing all four doses of RTS,S to the target e group through existing health services; pact of RTS,S on child mortality; idence of any causal relationship between RTS,S and either eningitis or cerebral malaria, in the context of surveillance of

11 Applications for Tackling Challenges in Control and Elimination

12 urance of Artemisinin Resistance

13 del predictions of Pre-Erythrocytic Vaccine effects over time terruption of transmission for initially low EIR ttings with very high efficacy vaccines Initial EIR 5.25 Initial EIR 21 EPI Mass vaccination CVEt () 0.76 V time (years) Vaccine half-life 10 years

14 ations in Surveillance Response systems: screening and treatment (FSAT) in areas assively-detected foci rrounding houses with very test (e.g. LAMP) to detect atic cases Malaria cases presenting at health centres over a few months Eliminate all malaria cases in area

15 me take home messages rrent malaria control and elimination tools do not vide complete protection. tially efficacious malaria vaccines are of benefits ublic health setting especially in high burden as. t implementation of first generation malaria cine will provide insights in the best approach for ge scale deployments loration of use of vaccines also to address erging challenges (drug and insecticide istance and responses to hot spots) to control elimination need to be implemented.

16