Pregnancy Outcomes among Women Receiving rVSVΔ-ZEBOV-GP Ebola Vaccine during the Sierra Leone Trial to Introduce a Vaccine against Ebola

Emerg Infect Dis. 2020 Mar;26(3):541-548. doi: 10.3201/eid2603.191018. Epub 2020 Mar 17.


Little information exists regarding Ebola vaccine rVSVΔG-ZEBOV-GP and pregnancy. The Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE) randomized participants without blinding to immediate or deferred (18-24 weeks postenrollment) vaccination. Pregnancy was an exclusion criterion, but 84 women were inadvertently vaccinated in early pregnancy or became pregnant <60 days after vaccination or enrollment. Among immediate vaccinated women, 45% (14/31) reported pregnancy loss, compared with 33% (11/33) of unvaccinated women with contemporaneous pregnancies (relative risk 1.35, 95% CI 0.73-2.52). Pregnancy loss was similar among women with higher risk for vaccine viremia (conception before or <14 days after vaccination) (44% [4/9]) and women with lower risk (conception >15 days after vaccination) (45% [10/22]). No congenital anomalies were detected among 44 live-born infants examined. These data highlight the need for Ebola vaccination decisions to balance the possible risk for an adverse pregnancy outcome with the risk for Ebola exposure.

Trial registration: NCT02378753.

Keywords: Ebola; Ebola vaccine; Ebola virus; Ebola virus disease; STRIVE; Sierra Leone; Sierra Leone Trial to Introduce a Vaccine against Ebola; West Africa; pregnancy; rVSVΔ-ZEBOV-GP; vaccine safety; vaccine-preventable diseases; viruses.

Publication types

  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Double-Blind Method
  • Ebola Vaccines / adverse effects
  • Ebola Vaccines / immunology*
  • Female
  • Hemorrhagic Fever, Ebola / epidemiology*
  • Hemorrhagic Fever, Ebola / prevention & control
  • Humans
  • Pregnancy
  • Pregnancy Complications, Infectious / epidemiology*
  • Pregnancy Complications, Infectious / prevention & control
  • Pregnancy Outcome
  • Prenatal Care*
  • Sierra Leone / epidemiology
  • Vaccination
  • Young Adult


  • Ebola Vaccines

Associated data

  • PACTR/PACTR201502001037220