Could Less Be More? Accounting for Fractional-Dose Regimens and Different Number of Vaccine Doses When Measuring the Impact of the RTS,S/AS01E Malaria Vaccine.
J Infect Dis
; 230(2): e486-e495, 2024 Aug 16.
Article
en En
| MEDLINE
| ID: mdl-38438123
ABSTRACT
BACKGROUND:
The RTS,S/AS01E (RTS,S) malaria vaccine is recommended for children in malaria endemic areas. This phase 2b trial evaluates RTS,S fractional- and full-dose regimens in Ghana and Kenya.METHODS:
In total, 1500 children aged 5-17 months were randomized (11111) to receive RTS,S or rabies control vaccine. RTS,S groups received 2 full RTS,S doses at months 0 and 1 and either full (groups R012-20, R012-14-26) or fractional doses (one-fifth; groups Fx012-14-26, Fx017-20-32).RESULTS:
At month 32 post-dose 1, vaccine efficacy against clinical malaria (all episodes) ranged from 38% (R012-20; 95% confidence interval [CI] 24%-49%) to 53% (R012-14-26; 95% CI 42%-62%). Vaccine impact (cumulative number of cases averted/1000 children vaccinated) was 1344 (R012-20), 2450 (R012-14-26), 2273 (Fx012-14-26), and 2112 (Fx017-20-32). To account for differences in vaccine volume (fractional vs full dose; post hoc analysis), we estimated cases averted/1000 RTS,S full-dose equivalents 336 (R012-20), 490 (R012-14-26), 874 (Fx012-14-26), and 880 (Fx017-20-32).CONCLUSIONS:
Vaccine efficacy was similar across RTS,S groups. Vaccine impact accounting for full-dose equivalence suggests that using fractional-dose regimens could be a viable dose-sparing strategy. If maintained through trial end, these observations underscore the means to reduce cost per regimen thus maximizing impact and optimizing supply. CLINICAL TRIALS REGISTRATION NCT03276962 (ClinicalTrials.gov).Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Malaria Falciparum
/
Vacunas contra la Malaria
/
Eficacia de las Vacunas
Límite:
Female
/
Humans
/
Infant
/
Male
País como asunto:
Africa
Idioma:
En
Año:
2024
Tipo del documento:
Article