Boni M. Alé (France)
Institut National de la Santé et de la Recherche Médicale StatisticsAuthor Of 1 Presentation
SAFETY AND IMMUNOGENICITY OF A TWO-DOSE AD26.ZEBOV, MVA-BN-FILO EBOLA VACCINE REGIMEN IN INFANTS: A RANDOMISED, DOUBLE-BLIND, CONTROLLED TRIAL IN SIERRA LEONE AND GUINEA
Abstract
Backgrounds:
Young children infected with Ebola have high mortality. A heterologous two-dose vaccine regimen (Ad26.ZEBOV [Ad26], MVA-BN-Filo [MVA]) was investigated in infants.
Methods
Healthy infants (4-11 months) in Sierra Leone and Guinea were randomised in a double-blind study to receive Ad26, MVA or Meningococcal Group A, C, W135, Y conjugate vaccine (MenACWY) 56 days apart. Adverse events (AEs) were assessed following each vaccine dose. Serious AEs (SAEs) were assessed from informed consent signing until six months post-dose 2. Binding antibody concentrations against EBOV GP were measured by FANG ELISA at baseline, 21 days post-dose 2, and one year post-dose 1.
Results:
A total of 108 infants underwent randomisation: 75 with Ad26, MVA and 33 with MenACWY. The vaccine regimen was well tolerated. The safety profile consisted of mild-to-moderate AEs, with the most common solicited AEs being irritability, decreased appetite, and pyrexia ≥38°C. Pyrexia was more frequent with Ad26, MVA versus control. The frequency of unsolicited AEs was similar in the Ad26, MVA and control groups. No SAEs were related to either vaccine. Strong humoral immune responses were observed in all infants who received the Ad26, MVA vaccine regimen at 21 days post-dose 2 and persisted up to one year in 96% of participants.
Conclusions/Learning Points:
The Ad26, MVA Ebola vaccine regimen was well tolerated, induced strong antibody responses in infants, and is suitable for preventing Ebola in infant populations. Binding antibody responses were comparable to levels previously reported in African children (1-3 years) and higher than the response in older children and adults.