Ebola: Control, Vaccination and Prevention
During the outbreak in West Africa in 2014-2016, all that could be done for Ebola prevention was to isolate patients, provide supportive care, and administer patients largely ineffective drugs. At the time, there was no Ebola vaccination available that had proven effective in humans and was registered for use in patients.
With the vaccines and experimental drugs available to us in 2019, MSF teams were able to offer people the chance to protect themselves individually as well as access to promising treatments.
There are now two vaccines against Ebola, which are in clinical study phases and are not licenced. One, the rVSV-ZEBOV vaccine produced by Merck, has been used in a 'ring' vaccination strategy since the beginning of 2019 (read more about this below). As of 7 March 2020, more than 300,300 people have been given this vaccine.
A second vaccine produced by Johnson&Johnson Ad26.ZEBOV/MVA-BN-Filo, began to be used by MSF teams in mid-November, following an announcement by the Ministry of Health.
While vaccination is a good measure designed to prevent the disease from spreading further, treatments alone won't end any Ebola outbreak. Responders still need to urgently find a way to cut transmission.
What is ‘ring’ vaccination?
Ring vaccination entails vaccinating anyone who has been in contact with someone infected with Ebola (first-degree contacts) as well as all their contacts (second-degree contacts, or ‘contacts of contacts’).
Implementing this method is time-consuming and challenging, as there are problems with identifying each and every person’s individual contacts, and it’s not adapted to the insecurity affecting DRC. In addition, the number of people vaccinated is too small to contain the spread of the epidemic.
MSF's vaccination strategy incorporated more geographical targeting of areas of high transmission and facilitating access to vaccination for more people, including all those at the highest risk. There were nonetheless challenges posed by transporting vaccines that must be stored at a constant temperature of -60°C across large geographical areas.