Journal article
Duration of vaccine efficacy against malaria: 5th year of follow-up in children vaccinated with RTS,S/AS02 in Mozambique
A primary concern for the RTS,S malaria vaccine candidate is duration of protection. The ongoing Phase III trial reported evidence of waning efficacy within the first year following vaccination. Multiple Phase IIb trials demonstrated early waning of efficacy. The longest duration of protection for RTS,S recorded to date was in a trial of a cohort of 1605 Mozambican children age 1–4 yr at the time of immunization (C1), which showed an overall efficacy against clinical malaria of 30.5% over 43 subsequent months of surveillance. A significant reduction in parasite prevalence in RTS,S vaccinees indicated that the vaccine continued to protect at the end of this period. Although follow-up for recording incident cases of clinical malaria was stopped at 45 months, the researchers were interested in evidence of further durability of protection, and revisited the cohort at 63 months, recording the secondary trial endpoint, prevalence of asexual Plasmodium falciparum parasitemia, in the RTS,S and comparator vaccine groups as a proxy for efficacy.
Authors
Languages
- English
Publication year
2014
Journal
Vaccine
Volume
32
Issue
19
Type
Journal article
Categories
- Vaccines & delivery devices
Diseases
- Malaria
Countries
- Mozambique
Tags
- Disease surveillance
WHO Regions
- African Region
