Last Wednesday 20 February, a committee advising the Congolese Ministry of Health made the decision to provide the Ebola vaccine to pregnant and breastfeeding women, as well as babies under one year old, in the eastern Democratic Republic of the Congo (DRC). In a policy U-turn, the decision was also backed by the World Health Organisation (WHO) based on the advice of an independent advisory body ― the strategic advisory group of experts on immunization (SAGE).
Current WHO estimates place the number of Ebola cases in the DRC at 853 and there have been 521 deaths since the beginning of the outbreak in August 2018. The outbreak is worsened by ongoing armed conflict in the North Kivu Province.
The vaccine ― rVSV-ZEBOV ― being developed by Merck it is shown to be highly effective against the particular strain of the Ebola virus devastating the North Kivu region but still experimental and not yet licensed. Nonetheless, since August last year, the WHO and DRC have been offering the vaccine to anyone that has been in contact with an Ebola victim, as well as the contacts-of-contacts. This so-called ring vaccination minimises the spread of the disease by vaccinating those likely to be infected.
However, until last week’s decision, the experimental Ebola vaccination was being withheld from pregnant and lactating women and children under one, despite the extremely high fatality rates of this particular demographic ― 80 per cent or higher upon contracting the Ebola virus ― moreover, nearly all pregnant survivors miscarry (1).
This previous hesitancy to give the vaccine to pregnant women is based on the fact that it is made from a live livestock virus ― vesicular stomatitis virus ― modified to contain a protein from the Ebola virus that teaches the immune system to fight Ebola. The vesicular stomatitis virus does not cause disease in humans, but could potentially harm the foetus, although there is currently no evidence of this. Furthermore, there is a potential risk that breastfeeding women may pass on the virus to their babies through breastmilk.
Advocates for vaccinating pregnant women against Ebola have long argued that under the given circumstances, the potential benefits far outweigh the potential harm. Moreover, unless the vaccine is actually given to pregnant women, there will be no data to determine whether it is safe or not. This knowledge would also be beneficial in future outbreaks, according to a statement given by Carleigh Krubiner, a policy fellow at the Center for Global Development.
Krubiner also added in her statement, “The DRC’s decision to extend Ebola vaccine coverage to pregnant women is a huge step forward, not only for pregnant women in areas affected by outbreaks but for all pregnant women who may face the threat of Ebola in the future.” The recent decision has been praised by many others as well, including Doctors Without Borders.
Vaccinated pregnant women in the DRC will be closely monitored until after they have given birth to determine whether the vaccine has any adverse effects. The panel of experts has also recommended including pregnant and breastfeeding women in trials of three other new experimental Ebola vaccines on at-risk populations in neighbouring areas.
(1) Black, B.O., Caluwaerts, S., and Achar, J. 2015. Ebola viral disease and pregnancy. Obstetric Medicine. DOI: 10.1177/1753495X15597354