ays after the Democratic Republic of the Congo declared an end to a deadly Ebola outbreak in the western province of Équateur, a new one emerged in North Kivu province. With the number of cases and death toll rising rapidly, the country’s ministry of health, the World Health Organization, and partners are working to launch a rapid and effective response that includes the use of an experimental vaccine. But their decision not to vaccinate women who are pregnant or lactating unfairly deprives them of the protection they deserve against this deadly disease.
The latest outbreak is due to the Zaire strain of the Ebola virus, a highly lethal variant that was responsible for more than 11,000 deaths in the 2013-2016 epidemic in West Africa and which killed 60 percent of those infected in the recent initial DRC outbreak. The new Ebola eruption has the potential to be even more lethal, as the North Kivu Province is the site of an ongoing armed conflict that makes medical treatment far more difficult to provide.
Fortunately, an experimental vaccine called rVSV-ZEBOV has been shown to be highly effective against this strain of Ebola virus. The DRC’s ministry of health, along with WHO and partners, has already begun employing the vaccine using the highly successful ring vaccination strategy, in which contacts and contacts-of-contacts of people with Ebola are offered the vaccine to halt the spread of the disease.
Some contacts, though, won’t get the vaccine. Pregnant women and those who are lactating are being excluded from this life-saving intervention. From a public health perspective and an ethical perspective, the decision to exclude pregnant and lactating women is utterly indefensible.
There’s no question that evidence about the safety of the Ebola vaccine in pregnancy is limited. But what we don’t know is dwarfed by what we do know. We know that in previous outbreaks, up to 90 percent of pregnant women infected with Ebola died from it. We know that nearly 100 percent of the pregnancies of Ebola-infected women end in miscarriage or neonatal death. And we also know that pregnant and lactating women are more likely than many others in the population to be caring for sick relatives, and thus are among those most likely to be infected. Indeed, the most recent WHO situation report on Ebola in the DRC shows that a large proportion of the cases are among women of childbearing potential.
The rVSV-ZEBOV vaccine is currently the only Ebola vaccine that has successfully completed efficacy trials and is being used in response efforts. This vaccine would not likely be viewed as appropriate for use in pregnant women outside the context of an Ebola outbreak. But during a high-incidence Ebola outbreak, the catastrophic maternal and fetal mortality rates change the calculus, with the potential benefits of offering the vaccine to pregnant contacts clearly outweighing the potential harms.
This favorable benefit-risk assessment is bolstered by the fact that in a previous trial, at least 20 women unintentionally received the Ebola vaccine while pregnant, with no evidence of harm.
rVSV-ZEBOV is a live vaccine, and live vaccines are not routinely given during pregnancy. Yet WHO recommendations regarding the use of a live yellow fever vaccine provide an important example of what could and should be done now with a live vaccine for Ebola. In its consideration of the benefits and risks of administering yellow fever vaccine to pregnant and lactating women at high risk of infection, WHO guidance states: “In [yellow fever] endemic areas, or during outbreaks, the benefits of [yellow fever] vaccination are likely to far outweigh the risk of potential transmission of vaccine virus to the fetus or infant.”
The same thinking should apply to Ebola. The rVSV-ZEBOV vaccine will give pregnant women, and the children they are carrying, a chance to live. Without it, most of the pregnant women infected with Ebola, and almost all of their infants, will die.
Current considerations related to the rVSV-ZEBOV vaccine and pregnant women highlight additional issues related to the equitable inclusion of the interests of pregnant women and their offspring in development and deployment of vaccines for emerging epidemic threats. For example, failure to routinely include pregnancy status in infectious disease surveillance systems means that accurate epidemiologic risk data are often unavailable. And failure to appropriately include pregnant women in vaccine research means that evidence about safety and effectiveness of vaccines in pregnancy has been limited and late in coming. As a result, pregnant women continue to be denied opportunities to receive vaccines that would protect them and their offspring during outbreaks and epidemics.
The Pregnancy Research Ethics for Vaccines, Epidemics, and New Technologies (PREVENT) Working Group, of which we are members, has brought together an international team of experts in bioethics, maternal immunization, maternal-fetal medicine, obstetrics, pediatrics, philosophy, public health, and vaccine research to provide specific recommendations developed to address this critical gap in vaccine research and development and epidemic response. This group recognizes that excluding pregnant women from efforts to develop and deploy vaccines against emerging threats is not acceptable. Business as usual can no longer continue.
The PREVENT team is creating a road map for the ethically responsible, socially just, and respectful inclusion of the interests of pregnant women in the development and deployment of vaccines against emerging pathogens. But pregnant and lactating women in North Kivu province can’t wait for our recommendations to be released and implemented. Continued exclusion of pregnant and lactating women from the Ebola vaccine response would be profoundly unfair — and profoundly unwise.
The DRC ministry of health and the WHO must recognize that women who are pregnant or lactating and who are contacts of Ebola patients must be given equal treatment. They are as entitled as any other contacts to the lifesaving benefits of the rVSV-ZEBOV vaccine.
Ruth R. Faden is the founder and inaugural director of the Johns Hopkins Berman Institute of Bioethics. Ruth A. Karron is director of the Center for Immunization Research and director of the Johns Hopkins Vaccine Initiative. Carleigh Krubiner is a policy fellow at the Center for Global Development.